feat(textbooks): 教材模块审计重构 — 跨模块解耦 + 权限 + i18n + 错误边界 + 纯函数抽取

P0 修复： - 解耦跨模块 UI 依赖：knowledge-point-dialogs 不再直接 import questions，改为 renderQuestionCreator render prop 由页面注入 - 接入 usePermission Hook 替换 canEdit 硬编码 - 全模块 i18n 改造：新增 en/zh-CN 翻译文件，替换所有硬编码文案 - Server Action 资源归属校验：新增 verifyChapterBelongsToTextbook/ verifyKnowledgePointBelongsToTextbook，在 reorder/update/delete/create 中校验 P1 改进： - 补齐 Error Boundary：4 个 error.tsx + TextbookSectionErrorBoundary 区块包裹 - 抽取纯函数到 utils.ts/graph-layout.ts/constants.ts 并补单测（26 用例全通过） - 消除重复组件：删除 knowledge-point-panel/create-knowledge-point-dialog - 修复类型断言：chapter.children! → 守卫式访问 - 图谱 a11y：添加 role/aria-label/aria-pressed - 统一删除确认：confirm() → AlertDialog - 数据范围过滤：getTextbooksWithScope 支持学生端按年级过滤 P2 预留： - TextbookAnalytics 埋点接口 + Provider + Hook 同步 005 架构数据 JSON：补充 getTextbooksWithScope/verify*/ChapterTreeNode 等
2026-06-22 16:25:59 +08:00
parent 45ee1ae43c
commit 22d3f07fcf
35 changed files with 2043 additions and 792 deletions
--- a/src/modules/textbooks/actions.ts
+++ b/src/modules/textbooks/actions.ts
@@ -14,7 +14,9 @@ import {
    updateKnowledgePoint,
    updateTextbook,
    deleteTextbook,
-    reorderChapters
+    reorderChapters,
+    verifyChapterBelongsToTextbook,
+    verifyKnowledgePointBelongsToTextbook,
 } from "./data-access";
 import {
    CreateTextbookSchema,
@@ -38,6 +40,11 @@ export async function reorderChaptersAction(
 ): Promise<ActionState> {
    try {
        await requirePermission(Permissions.TEXTBOOK_UPDATE);
+        // P0-4 资源归属校验：防止越权操作其他教材的章节
+        const belongs = await verifyChapterBelongsToTextbook(chapterId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Chapter does not belong to this textbook" };
+        }
        await reorderChapters(chapterId, newIndex, parentId);
        revalidatePath(`/teacher/textbooks/${textbookId}`);
        return { success: true, message: "Chapters reordered successfully" };
@@ -203,6 +210,11 @@ export async function updateChapterContentAction(

    try {
        await requirePermission(Permissions.TEXTBOOK_UPDATE);
+        // P0-4 资源归属校验
+        const belongs = await verifyChapterBelongsToTextbook(chapterId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Chapter does not belong to this textbook" };
+        }
        await updateChapterContent(parsed.data);
        revalidatePath(`/teacher/textbooks/${textbookId}`);
        return { success: true, message: "Content updated successfully" };
@@ -220,6 +232,11 @@ export async function deleteChapterAction(
 ): Promise<ActionState> {
    try {
        await requirePermission(Permissions.TEXTBOOK_DELETE);
+        // P0-4 资源归属校验
+        const belongs = await verifyChapterBelongsToTextbook(chapterId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Chapter does not belong to this textbook" };
+        }
        await deleteChapter(chapterId);
        revalidatePath(`/teacher/textbooks/${textbookId}`);
        return { success: true, message: "Chapter deleted successfully" };
@@ -254,6 +271,11 @@ export async function createKnowledgePointAction(

    try {
        await requirePermission(Permissions.TEXTBOOK_CREATE);
+        // P0-4 资源归属校验：确保 chapter 属于该 textbook，防止跨教材越权创建知识点
+        const chapterBelongs = await verifyChapterBelongsToTextbook(chapterId, textbookId);
+        if (!chapterBelongs) {
+            return { success: false, message: "Chapter does not belong to this textbook" };
+        }
        await createKnowledgePoint(parsed.data);
        revalidatePath(`/teacher/textbooks/${textbookId}`);
        return { success: true, message: "Knowledge point created successfully" };
@@ -271,6 +293,11 @@ export async function deleteKnowledgePointAction(
 ): Promise<ActionState> {
    try {
        await requirePermission(Permissions.TEXTBOOK_DELETE);
+        // P0-4 资源归属校验
+        const belongs = await verifyKnowledgePointBelongsToTextbook(kpId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Knowledge point does not belong to this textbook" };
+        }
        await deleteKnowledgePoint(kpId);
        revalidatePath(`/teacher/textbooks/${textbookId}`);
        return { success: true, message: "Knowledge point deleted successfully" };
@@ -305,6 +332,11 @@ export async function updateKnowledgePointAction(

    try {
        await requirePermission(Permissions.TEXTBOOK_UPDATE);
+        // P0-4 资源归属校验
+        const belongs = await verifyKnowledgePointBelongsToTextbook(kpId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Knowledge point does not belong to this textbook" };
+        }
        await updateKnowledgePoint(parsed.data);
        revalidatePath(`/teacher/textbooks/${textbookId}`);
        return { success: true, message: "Knowledge point updated successfully" };
--- a/src/modules/textbooks/analytics.tsx
+++ b/src/modules/textbooks/analytics.tsx
@@ -0,0 +1,43 @@
+/**
+ * 教材模块埋点接口（预留）。
+ *
+ * 当前为 no-op 实现，后续接入真实监控 SDK 时只需替换 Provider。
+ * 通过 React Context 注入，组件内调用 `useTextbookAnalytics()` 获取。
+ */
+
+"use client"
+
+import { createContext, useContext, type ReactNode } from "react"
+
+export interface TextbookAnalytics {
+  /** 教材被打开时触发 */
+  onTextbookOpen?(textbookId: string): void
+  /** 章节被阅读时触发（含停留时长） */
+  onChapterRead?(textbookId: string, chapterId: string, durationMs: number): void
+  /** 知识点被点击时触发 */
+  onKnowledgePointClick?(kpId: string): void
+  /** 知识点被创建时触发 */
+  onKnowledgePointCreate?(chapterId: string, kpId: string): void
+  /** 章节内容被编辑保存时触发 */
+  onChapterContentUpdate?(chapterId: string): void
+}
+
+const TextbookAnalyticsContext = createContext<TextbookAnalytics>({})
+
+export function TextbookAnalyticsProvider({
+  analytics,
+  children,
+}: {
+  analytics?: TextbookAnalytics
+  children: ReactNode
+}) {
+  return (
+    <TextbookAnalyticsContext.Provider value={analytics ?? {}}>
+      {children}
+    </TextbookAnalyticsContext.Provider>
+  )
+}
+
+export function useTextbookAnalytics(): TextbookAnalytics {
+  return useContext(TextbookAnalyticsContext)
+}
--- a/src/modules/textbooks/components/chapter-sidebar-list.tsx
+++ b/src/modules/textbooks/components/chapter-sidebar-list.tsx
@@ -136,9 +136,9 @@ function SortableChapterItem({ chapter, level, selectedId, onSelect, textbookId,
        
        <CollapsibleContent>
          <div className="pt-1">
-             {hasChildren && (
-                <RecursiveSortableList 
-                    items={chapter.children!} 
+             {hasChildren && chapter.children && (
+                <RecursiveSortableList
+                    items={chapter.children}
                    level={level + 1}
                    selectedId={selectedId}
                    onSelect={onSelect}
--- a/src/modules/textbooks/components/create-chapter-dialog.tsx
+++ b/src/modules/textbooks/components/create-chapter-dialog.tsx
@@ -3,6 +3,7 @@
 import { useState } from "react"
 import { Plus } from "lucide-react"
 import { useFormStatus } from "react-dom"
+import { useTranslations } from "next-intl"
 import { Button } from "@/shared/components/ui/button"
 import {
  Dialog,
@@ -20,9 +21,10 @@ import { toast } from "sonner"

 function SubmitButton() {
  const { pending } = useFormStatus()
+  const t = useTranslations("textbooks")
  return (
    <Button type="submit" disabled={pending}>
-      {pending ? "Creating..." : "Create Chapter"}
+      {pending ? t("dialog.chapter.creating") : t("dialog.chapter.submit")}
    </Button>
  )
 }
@@ -35,7 +37,14 @@ interface CreateChapterDialogProps {
  onOpenChange?: (open: boolean) => void
 }

-export function CreateChapterDialog({ textbookId, parentId, trigger, open: controlledOpen, onOpenChange }: CreateChapterDialogProps) {
+export function CreateChapterDialog({
+  textbookId,
+  parentId,
+  trigger,
+  open: controlledOpen,
+  onOpenChange,
+}: CreateChapterDialogProps) {
+  const t = useTranslations("textbooks")
  const [uncontrolledOpen, setUncontrolledOpen] = useState(false)
  const open = controlledOpen ?? uncontrolledOpen
  const setOpen = onOpenChange ?? setUncontrolledOpen
@@ -54,9 +63,13 @@ export function CreateChapterDialog({ textbookId, parentId, trigger, open: contr
    trigger === null
      ? null
      : trigger || (
-          <Button variant="ghost" size="icon" className="h-8 w-8 text-muted-foreground hover:text-foreground">
+          <Button
+            variant="ghost"
+            size="icon"
+            className="h-8 w-8 text-muted-foreground hover:text-foreground"
+          >
            <Plus className="h-4 w-4" />
-            <span className="sr-only">Add Chapter</span>
+            <span className="sr-only">{t("dialog.chapter.createTitle")}</span>
          </Button>
        )

@@ -65,21 +78,19 @@ export function CreateChapterDialog({ textbookId, parentId, trigger, open: contr
      {triggerNode ? <DialogTrigger asChild>{triggerNode}</DialogTrigger> : null}
      <DialogContent className="sm:max-w-[425px]">
        <DialogHeader>
-          <DialogTitle>Add New Chapter</DialogTitle>
-          <DialogDescription>
-            Create a new chapter or section.
-          </DialogDescription>
+          <DialogTitle>{t("dialog.chapter.createTitle")}</DialogTitle>
+          <DialogDescription>{t("dialog.chapter.createDesc")}</DialogDescription>
        </DialogHeader>
        <form action={handleSubmit}>
          <div className="grid gap-4 py-4">
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="title" className="text-right">
-                Title
+                {t("field.title")}
              </Label>
              <Input
                id="title"
                name="title"
-                placeholder="e.g. Chapter 1: Introduction"
+                placeholder={t("dialog.chapter.titlePlaceholder")}
                className="col-span-3"
                required
              />
--- a/src/modules/textbooks/components/create-knowledge-point-dialog.tsx
+++ b/src/modules/textbooks/components/create-knowledge-point-dialog.tsx
@@ -1,95 +0,0 @@
-"use client"
-
-import { useState } from "react"
-import { Plus } from "lucide-react"
-import { useFormStatus } from "react-dom"
-import { Button } from "@/shared/components/ui/button"
-import {
-  Dialog,
-  DialogContent,
-  DialogDescription,
-  DialogFooter,
-  DialogHeader,
-  DialogTitle,
-  DialogTrigger,
-} from "@/shared/components/ui/dialog"
-import { Input } from "@/shared/components/ui/input"
-import { Label } from "@/shared/components/ui/label"
-import { Textarea } from "@/shared/components/ui/textarea"
-import { createKnowledgePointAction } from "../actions"
-import { toast } from "sonner"
-
-function SubmitButton() {
-  const { pending } = useFormStatus()
-  return (
-    <Button type="submit" disabled={pending}>
-      {pending ? "Adding..." : "Add Point"}
-    </Button>
-  )
-}
-
-interface CreateKnowledgePointDialogProps {
-  chapterId: string
-  textbookId: string
-}
-
-export function CreateKnowledgePointDialog({ chapterId, textbookId }: CreateKnowledgePointDialogProps) {
-  const [open, setOpen] = useState(false)
-
-  const handleSubmit = async (formData: FormData) => {
-    const result = await createKnowledgePointAction(chapterId, textbookId, null, formData)
-    if (result.success) {
-      toast.success(result.message)
-      setOpen(false)
-    } else {
-      toast.error(result.message)
-    }
-  }
-
-  return (
-    <Dialog open={open} onOpenChange={setOpen}>
-      <DialogTrigger asChild>
-        <Button variant="ghost" size="sm" className="h-8 w-8 p-0">
-            <Plus className="h-4 w-4" />
-        </Button>
-      </DialogTrigger>
-      <DialogContent className="sm:max-w-[425px]">
-        <DialogHeader>
-          <DialogTitle>Add Knowledge Point</DialogTitle>
-          <DialogDescription>
-            Link a key concept to this chapter.
-          </DialogDescription>
-        </DialogHeader>
-        <form action={handleSubmit}>
-          <div className="grid gap-4 py-4">
-            <div className="grid gap-2">
-              <Label htmlFor="name">
-                Name
-              </Label>
-              <Input
-                id="name"
-                name="name"
-                placeholder="e.g. Pythagorean Theorem"
-                required
-              />
-            </div>
-            <div className="grid gap-2">
-              <Label htmlFor="description">
-                Description
-              </Label>
-              <Textarea
-                id="description"
-                name="description"
-                placeholder="Brief explanation..."
-                className="h-20"
-              />
-            </div>
-          </div>
-          <DialogFooter>
-            <SubmitButton />
-          </DialogFooter>
-        </form>
-      </DialogContent>
-    </Dialog>
-  )
-}
--- a/src/modules/textbooks/components/knowledge-graph.tsx
+++ b/src/modules/textbooks/components/knowledge-graph.tsx
@@ -1,120 +1,9 @@
 "use client"

 import { useMemo } from "react"
-
+import { useTranslations } from "next-intl"
 import type { KnowledgePoint } from "../types"
-import { cn } from "@/shared/lib/utils"
-import { ScrollArea } from "@/shared/components/ui/scroll-area"
-
-interface GraphNode extends KnowledgePoint {
-  x: number
-  y: number
-}
-
-interface GraphEdge {
-  id: string
-  x1: number
-  y1: number
-  x2: number
-  y2: number
-}
-
-interface GraphLayout {
-  nodes: GraphNode[]
-  edges: GraphEdge[]
-  width: number
-  height: number
-}
-
-function computeGraphLayout(knowledgePoints: KnowledgePoint[]): GraphLayout {
-  if (knowledgePoints.length === 0) {
-    return { nodes: [], edges: [], width: 0, height: 0 }
-  }
-
-  const byId = new Map<string, KnowledgePoint>()
-  for (const kp of knowledgePoints) byId.set(kp.id, kp)
-
-  const children = new Map<string, string[]>()
-  const roots: string[] = []
-
-  for (const kp of knowledgePoints) {
-    if (kp.parentId && byId.has(kp.parentId)) {
-      const arr = children.get(kp.parentId) ?? []
-      arr.push(kp.id)
-      children.set(kp.parentId, arr)
-    } else {
-      roots.push(kp.id)
-    }
-  }
-
-  const levelMap = new Map<string, number>()
-  const levels: string[][] = []
-  const queue = [...roots].map((id) => ({ id, level: 0 }))
-
-  if (queue.length === 0) {
-    for (const kp of knowledgePoints) queue.push({ id: kp.id, level: 0 })
-  }
-
-  while (queue.length > 0) {
-    const item = queue.shift()
-    if (!item) continue
-    if (levelMap.has(item.id)) continue
-    levelMap.set(item.id, item.level)
-    if (!levels[item.level]) levels[item.level] = []
-    levels[item.level].push(item.id)
-    const kids = children.get(item.id) ?? []
-    for (const kid of kids) {
-      if (!levelMap.has(kid)) queue.push({ id: kid, level: item.level + 1 })
-    }
-  }
-
-  for (const kp of knowledgePoints) {
-    if (!levelMap.has(kp.id)) {
-      const level = levels.length
-      levelMap.set(kp.id, level)
-      if (!levels[level]) levels[level] = []
-      levels[level].push(kp.id)
-    }
-  }
-
-  const nodeWidth = 160
-  const nodeHeight = 52
-  const gapX = 40
-  const gapY = 90
-  const maxCount = Math.max(...levels.map((l) => l.length), 1)
-  const width = maxCount * (nodeWidth + gapX) + gapX
-  const height = levels.length * (nodeHeight + gapY) + gapY
-
-  const positions = new Map<string, { x: number; y: number }>()
-  levels.forEach((ids, level) => {
-    ids.forEach((id, index) => {
-      const x = gapX + index * (nodeWidth + gapX)
-      const y = gapY + level * (nodeHeight + gapY)
-      positions.set(id, { x, y })
-    })
-  })
-
-  const nodes = knowledgePoints.map((kp) => {
-    const pos = positions.get(kp.id) ?? { x: gapX, y: gapY }
-    return { ...kp, x: pos.x, y: pos.y }
-  })
-
-  const edges = knowledgePoints
-    .filter((kp) => kp.parentId && positions.has(kp.parentId))
-    .map((kp) => {
-      const parentPos = positions.get(kp.parentId as string)!
-      const childPos = positions.get(kp.id)!
-      return {
-        id: `${kp.parentId}-${kp.id}`,
-        x1: parentPos.x + nodeWidth / 2,
-        y1: parentPos.y + nodeHeight,
-        x2: childPos.x + nodeWidth / 2,
-        y2: childPos.y,
-      }
-    })
-
-  return { nodes, edges, width, height }
-}
+import { computeGraphLayout, NODE_WIDTH, NODE_HEIGHT } from "../graph-layout"

 interface KnowledgeGraphProps {
  knowledgePoints: KnowledgePoint[]
@@ -122,60 +11,71 @@ interface KnowledgeGraphProps {
  onHighlight: (id: string) => void
 }

-export function KnowledgeGraph({ knowledgePoints, selectedId, onHighlight }: KnowledgeGraphProps) {
-  const graphLayout = useMemo(() => computeGraphLayout(knowledgePoints), [knowledgePoints])
+export function KnowledgeGraph({
+  knowledgePoints,
+  selectedId,
+  onHighlight,
+}: KnowledgeGraphProps) {
+  const t = useTranslations("textbooks")
+
+  const layout = useMemo(() => computeGraphLayout(knowledgePoints), [knowledgePoints])

  if (knowledgePoints.length === 0) {
    return (
      <div className="flex h-full items-center justify-center text-muted-foreground p-4 text-center text-sm">
-        该章节暂无知识点。
+        {t("reader.emptyKnowledge")}
      </div>
    )
  }

  return (
-    <ScrollArea className="flex-1 h-full px-2">
-      <div
-        className="relative"
-        style={{ width: graphLayout.width, height: graphLayout.height }}
+    <div className="h-full w-full overflow-auto p-4">
+      <svg
+        width={layout.width}
+        height={layout.height}
+        role="img"
+        aria-label={t("reader.tabs.graph")}
+        className="mx-auto"
      >
-        <svg
-          width={graphLayout.width}
-          height={graphLayout.height}
-          className="absolute inset-0"
-        >
-          {graphLayout.edges.map((edge) => (
-            <line
-              key={edge.id}
-              x1={edge.x1}
-              y1={edge.y1}
-              x2={edge.x2}
-              y2={edge.y2}
-              stroke="hsl(var(--border))"
-              strokeWidth={2}
-            />
-          ))}
-        </svg>
-        {graphLayout.nodes.map((node) => (
-          <button
-            key={node.id}
-            type="button"
-            className={cn(
-              "absolute rounded-lg border bg-card px-3 py-2 text-left text-sm shadow-sm hover:bg-accent/50",
-              selectedId === node.id && "border-primary bg-primary/5"
-            )}
-            style={{ left: node.x, top: node.y, width: 160, height: 52 }}
-            onClick={() => onHighlight(node.id)}
-          >
-            <div className="font-medium truncate">{node.name}</div>
-            {node.description && (
-              <div className="text-[10px] text-muted-foreground truncate">
-                {node.description}
-              </div>
-            )}
-          </button>
+        <title>{t("reader.tabs.graph")}</title>
+        {/* 边 */}
+        {layout.edges.map((edge) => (
+          <line
+            key={edge.id}
+            x1={edge.x1}
+            y1={edge.y1}
+            x2={edge.x2}
+            y2={edge.y2}
+            stroke="currentColor"
+            strokeOpacity={0.3}
+            strokeWidth={1.5}
+          />
        ))}
-      </div>
-    </ScrollArea>
+
+        {/* 节点 */}
+        {layout.nodes.map((node) => {
+          const isSelected = selectedId === node.id
+          return (
+            <g key={node.id} transform={`translate(${node.x}, ${node.y})`}>
+              <foreignObject width={NODE_WIDTH} height={NODE_HEIGHT}>
+                <button
+                  type="button"
+                  onClick={() => onHighlight(node.id)}
+                  className={`flex h-full w-full items-center justify-center rounded-lg border-2 px-3 text-center text-xs font-medium transition-colors cursor-pointer ${
+                    isSelected
+                      ? "border-primary bg-primary/10 text-primary"
+                      : "border-border bg-card text-card-foreground hover:border-primary/50 hover:bg-accent"
+                  }`}
+                  aria-label={`${t("reader.clickToViewKp")}: ${node.name}`}
+                  aria-pressed={isSelected}
+                >
+                  <span className="line-clamp-2">{node.name}</span>
+                </button>
+              </foreignObject>
+            </g>
+          )
+        })}
+      </svg>
+    </div>
  )
 }
--- a/src/modules/textbooks/components/knowledge-point-dialogs.tsx
+++ b/src/modules/textbooks/components/knowledge-point-dialogs.tsx
@@ -1,5 +1,7 @@
 "use client"

+import type { ReactNode } from "react"
+import { useTranslations } from "next-intl"
 import type { KnowledgePoint } from "../types"
 import { Button } from "@/shared/components/ui/button"
 import {
@@ -13,9 +15,20 @@ import {
 import { Input } from "@/shared/components/ui/input"
 import { Label } from "@/shared/components/ui/label"
 import { Textarea } from "@/shared/components/ui/textarea"
-import { CreateQuestionDialog } from "@/modules/questions/components/create-question-dialog"

-interface KnowledgePointDialogsProps {
+/**
+ * 题目创建器的渲染接口。
+ *
+ * 通过 render prop 注入，避免 textbooks 模块直接 import questions 模块组件（P0-1 解耦）。
+ * 页面层负责传入实际的 CreateQuestionDialog 实现。
+ */
+export interface QuestionCreatorRenderProps {
+  open: boolean
+  onOpenChange: (open: boolean) => void
+  targetKp: KnowledgePoint | null
+}
+
+export interface KnowledgePointDialogsProps {
  // Create KP dialog
  createDialogOpen: boolean
  setCreateDialogOpen: (open: boolean) => void
@@ -30,10 +43,16 @@ interface KnowledgePointDialogsProps {
  isUpdatingKp: boolean
  onUpdateKnowledgePoint: (formData: FormData) => Promise<void>

-  // Question dialog
+  // Question dialog（通过 render prop 注入，解耦 questions 模块）
  questionDialogOpen: boolean
  setQuestionDialogOpen: (open: boolean) => void
  targetKpForQuestion: KnowledgePoint | null
+  /**
+   * 题目创建器渲染函数。
+   * 由页面层注入实际的 questions 模块组件，模块内部不直接 import questions。
+   * 若不传则不渲染题目创建入口（学生端等无权限场景）。
+   */
+  renderQuestionCreator?: (props: QuestionCreatorRenderProps) => ReactNode
 }

 export function KnowledgePointDialogs({
@@ -50,34 +69,35 @@ export function KnowledgePointDialogs({
  questionDialogOpen,
  setQuestionDialogOpen,
  targetKpForQuestion,
+  renderQuestionCreator,
 }: KnowledgePointDialogsProps) {
+  const t = useTranslations("textbooks.dialog.knowledge")
+
  return (
    <>
      <Dialog open={createDialogOpen} onOpenChange={setCreateDialogOpen}>
        <DialogContent>
          <DialogHeader>
-            <DialogTitle>添加知识点</DialogTitle>
-            <DialogDescription>
-              从选中的文本创建知识点。
-            </DialogDescription>
+            <DialogTitle>{t("createTitle")}</DialogTitle>
+            <DialogDescription>{t("createDesc")}</DialogDescription>
          </DialogHeader>
          <form action={onCreateKnowledgePoint as (formData: FormData) => void}>
            <div className="grid gap-4 py-4">
              <div className="grid gap-2">
-                <Label htmlFor="name">名称</Label>
+                <Label htmlFor="name">{t("name")}</Label>
                <Input id="name" name="name" defaultValue={selectedText} required />
              </div>
              <div className="grid gap-2">
-                <Label htmlFor="description">描述（可选）</Label>
-                <Textarea id="description" name="description" placeholder="请输入描述..." />
+                <Label htmlFor="description">{t("description")}</Label>
+                <Textarea id="description" name="description" placeholder={t("descriptionPlaceholder")} />
              </div>
            </div>
            <DialogFooter>
              <Button type="button" variant="outline" onClick={() => setCreateDialogOpen(false)} disabled={isCreating}>
-                取消
+                {t("cancel")}
              </Button>
              <Button type="submit" disabled={isCreating}>
-                {isCreating ? "创建中..." : "创建"}
+                {isCreating ? t("creating") : t("create")}
              </Button>
            </DialogFooter>
          </form>
@@ -87,26 +107,32 @@ export function KnowledgePointDialogs({
      <Dialog open={editKpDialogOpen} onOpenChange={setEditKpDialogOpen}>
        <DialogContent>
          <DialogHeader>
-            <DialogTitle>编辑知识点</DialogTitle>
-            <DialogDescription>
-              修改知识点的名称和描述。
-            </DialogDescription>
+            <DialogTitle>{t("editTitle")}</DialogTitle>
+            <DialogDescription>{t("editDesc")}</DialogDescription>
          </DialogHeader>
          <form action={onUpdateKnowledgePoint}>
            <div className="grid gap-4 py-4">
              <div className="grid gap-2">
-                <Label htmlFor="edit-name">显示名称</Label>
+                <Label htmlFor="edit-name">{t("displayName")}</Label>
                <Input id="edit-name" name="name" defaultValue={editingKp?.name} required />
              </div>
              <div className="grid gap-2">
-                <Label htmlFor="edit-description">描述（可选）</Label>
-                <Textarea id="edit-description" name="description" defaultValue={editingKp?.description || ""} placeholder="请输入描述..." />
+                <Label htmlFor="edit-description">{t("description")}</Label>
+                <Textarea
+                  id="edit-description"
+                  name="description"
+                  defaultValue={editingKp?.description || ""}
+                  placeholder={t("descriptionPlaceholder")}
+                />
              </div>

              <div className="space-y-2 border rounded-md p-3 bg-muted/20">
                <div className="flex items-center justify-between">
-                  <Label htmlFor="edit-anchorText" className="text-muted-foreground text-xs flex items-center gap-1">
-                    高级：关联文本 (影响文中高亮)
+                  <Label
+                    htmlFor="edit-anchorText"
+                    className="text-muted-foreground text-xs flex items-center gap-1"
+                  >
+                    {t("anchorText")}
                  </Label>
                </div>
                <div className="pt-2">
@@ -118,31 +144,32 @@ export function KnowledgePointDialogs({
                    className="text-sm font-mono"
                    required
                  />
-                  <p className="text-[10px] text-muted-foreground mt-1">
-                    修改此字段会改变文中被高亮匹配的文字。通常保持与原文一致。
-                  </p>
+                  <p className="text-[10px] text-muted-foreground mt-1">{t("anchorTextHint")}</p>
                </div>
              </div>
            </div>
            <DialogFooter>
-              <Button type="button" variant="outline" onClick={() => setEditKpDialogOpen(false)} disabled={isUpdatingKp}>
-                取消
+              <Button
+                type="button"
+                variant="outline"
+                onClick={() => setEditKpDialogOpen(false)}
+                disabled={isUpdatingKp}
+              >
+                {t("cancel")}
              </Button>
              <Button type="submit" disabled={isUpdatingKp}>
-                {isUpdatingKp ? "保存中..." : "保存"}
+                {isUpdatingKp ? t("saving") : t("save")}
              </Button>
            </DialogFooter>
          </form>
        </DialogContent>
      </Dialog>

-      <CreateQuestionDialog
-        open={questionDialogOpen}
-        onOpenChange={setQuestionDialogOpen}
-        defaultKnowledgePointIds={targetKpForQuestion ? [targetKpForQuestion.id] : []}
-        defaultContent={targetKpForQuestion ? `Please explain the knowledge point: ${targetKpForQuestion.name}` : ""}
-        defaultType="text"
-      />
+      {renderQuestionCreator?.({
+        open: questionDialogOpen,
+        onOpenChange: setQuestionDialogOpen,
+        targetKp: targetKpForQuestion,
+      })}
    </>
  )
 }
--- a/src/modules/textbooks/components/knowledge-point-list.tsx
+++ b/src/modules/textbooks/components/knowledge-point-list.tsx
@@ -1,6 +1,7 @@
 "use client"

 import { PlusCircle, Pencil, Trash2 } from "lucide-react"
+import { useTranslations } from "next-intl"

 import type { KnowledgePoint } from "../types"
 import { cn } from "@/shared/lib/utils"
@@ -11,6 +12,8 @@ import { Button } from "@/shared/components/ui/button"
 interface KnowledgePointListProps {
  knowledgePoints: KnowledgePoint[]
  canEdit: boolean
+  /** 是否有创建题目权限（控制"创建相关题目"按钮可见性） */
+  canCreateQuestion?: boolean
  highlightedKpId: string | null
  onHighlight: (id: string) => void
  onEdit: (kp: KnowledgePoint) => void
@@ -21,16 +24,19 @@ interface KnowledgePointListProps {
 export function KnowledgePointList({
  knowledgePoints,
  canEdit,
+  canCreateQuestion = false,
  highlightedKpId,
  onHighlight,
  onEdit,
  onDelete,
  onCreateQuestion,
 }: KnowledgePointListProps) {
+  const t = useTranslations("textbooks")
+
  if (knowledgePoints.length === 0) {
    return (
      <div className="flex h-full items-center justify-center text-muted-foreground p-4 text-center text-sm">
-        该章节暂无知识点。
+        {t("reader.emptyKnowledge")}
      </div>
    )
  }
@@ -51,22 +57,27 @@ export function KnowledgePointList({
            <div className="flex items-start justify-between gap-2">
              <h4 className="text-sm font-medium leading-none">{kp.name}</h4>
              <div className="flex items-center gap-1">
-                <Badge variant="outline" className="text-[10px] h-5 px-1">Lv.{kp.level}</Badge>
+                <Badge variant="outline" className="text-[10px] h-5 px-1">
+                  {t("panel.level")}
+                  {kp.level}
+                </Badge>
                {canEdit && (
                  <div className="flex items-center gap-1 ml-1">
-                    <Button
-                      variant="ghost"
-                      size="icon"
-                      className="h-5 w-5 text-muted-foreground hover:text-foreground"
-                      onClick={(e) => {
-                        e.stopPropagation()
-                        onCreateQuestion(kp)
-                      }}
-                      title="创建相关题目"
-                      aria-label="创建相关题目"
-                    >
-                      <PlusCircle className="h-3 w-3" />
-                    </Button>
+                    {canCreateQuestion && (
+                      <Button
+                        variant="ghost"
+                        size="icon"
+                        className="h-5 w-5 text-muted-foreground hover:text-foreground"
+                        onClick={(e) => {
+                          e.stopPropagation()
+                          onCreateQuestion(kp)
+                        }}
+                        title={t("dialog.knowledge.createQuestion")}
+                        aria-label={t("dialog.knowledge.createQuestion")}
+                      >
+                        <PlusCircle className="h-3 w-3" />
+                      </Button>
+                    )}
                    <Button
                      variant="ghost"
                      size="icon"
@@ -75,8 +86,8 @@ export function KnowledgePointList({
                        e.stopPropagation()
                        onEdit(kp)
                      }}
-                      title="编辑知识点"
-                      aria-label="编辑知识点"
+                      title={t("dialog.knowledge.editKp")}
+                      aria-label={t("dialog.knowledge.editKp")}
                    >
                      <Pencil className="h-3 w-3" />
                    </Button>
@@ -85,8 +96,8 @@ export function KnowledgePointList({
                      size="icon"
                      className="h-5 w-5 text-muted-foreground hover:text-destructive"
                      onClick={(e) => onDelete(kp.id, e)}
-                      title="删除知识点"
-                      aria-label="删除知识点"
+                      title={t("dialog.knowledge.deleteKp")}
+                      aria-label={t("dialog.knowledge.deleteKp")}
                    >
                      <Trash2 className="h-3 w-3" />
                    </Button>
--- a/src/modules/textbooks/components/knowledge-point-panel.tsx
+++ b/src/modules/textbooks/components/knowledge-point-panel.tsx
@@ -1,157 +0,0 @@
-"use client"
-
-import { useState } from "react"
-import { useRouter } from "next/navigation"
-import { Card, CardContent } from "@/shared/components/ui/card"
-import { Button } from "@/shared/components/ui/button"
-import { Tag, Trash2 } from "lucide-react"
-import { KnowledgePoint } from "../types"
-import { CreateKnowledgePointDialog } from "./create-knowledge-point-dialog"
-import { deleteKnowledgePointAction } from "../actions"
-import { toast } from "sonner"
-import { ScrollArea } from "@/shared/components/ui/scroll-area"
-import {
-  AlertDialog,
-  AlertDialogAction,
-  AlertDialogCancel,
-  AlertDialogContent,
-  AlertDialogDescription,
-  AlertDialogFooter,
-  AlertDialogHeader,
-  AlertDialogTitle,
-} from "@/shared/components/ui/alert-dialog"
-
-interface KnowledgePointPanelProps {
-  knowledgePoints: KnowledgePoint[]
-  selectedChapterId: string | null
-  textbookId: string
-}
-
-export function KnowledgePointPanel({ 
-  knowledgePoints, 
-  selectedChapterId, 
-  textbookId 
-}: KnowledgePointPanelProps) {
-  const router = useRouter()
-  const [showDeleteDialog, setShowDeleteDialog] = useState(false)
-  const [deleteTarget, setDeleteTarget] = useState<KnowledgePoint | null>(null)
-  const [isDeleting, setIsDeleting] = useState(false)
-  
-  const requestDelete = (kp: KnowledgePoint) => {
-    setDeleteTarget(kp)
-    setShowDeleteDialog(true)
-  }
-
-  const handleDelete = async () => {
-    if (!deleteTarget) return
-    setIsDeleting(true)
-    try {
-      const result = await deleteKnowledgePointAction(deleteTarget.id, textbookId)
-      if (result.success) {
-        toast.success(result.message)
-        setShowDeleteDialog(false)
-        setDeleteTarget(null)
-        router.refresh()
-      } else {
-        toast.error(result.message)
-      }
-    } catch {
-      toast.error("Failed to delete knowledge point")
-    } finally {
-      setIsDeleting(false)
-    }
-  }
-
-  // Filter KPs for the selected chapter
-  const chapterKPs = selectedChapterId 
-    ? knowledgePoints.filter(kp => kp.chapterId === selectedChapterId)
-    : []
-
-  return (
-    <div className="h-full flex flex-col">
-      <div className="flex items-center justify-between p-4 border-b">
-        <h3 className="font-semibold text-sm uppercase tracking-wider text-muted-foreground flex items-center gap-2">
-            <Tag className="h-4 w-4" />
-            Knowledge Points
-        </h3>
-        {selectedChapterId && (
-            <CreateKnowledgePointDialog 
-                chapterId={selectedChapterId} 
-                textbookId={textbookId} 
-            />
-        )}
-      </div>
-
-      <ScrollArea className="flex-1">
-        <div className="p-4 space-y-3">
-        {selectedChapterId ? (
-            chapterKPs.length > 0 ? (
-                <>
-                    {chapterKPs.map((kp) => (
-                        <Card key={kp.id} className="relative group hover:shadow-sm transition-shadow">
-                            <CardContent className="p-3">
-                                <div className="flex justify-between items-start gap-2">
-                                    <div className="space-y-1">
-                                        <div className="font-medium text-sm leading-tight text-foreground">
-                                            {kp.name}
-                                        </div>
-                                        {kp.description && (
-                                            <p className="text-xs text-muted-foreground line-clamp-2">
-                                                {kp.description}
-                                            </p>
-                                        )}
-                                    </div>
-                                    <Button
-                                        variant="ghost"
-                                        size="icon"
-                                        className="h-6 w-6 -mr-1 -mt-1 opacity-0 group-hover:opacity-100 transition-opacity text-muted-foreground hover:text-destructive"
-                                        onClick={() => requestDelete(kp)}
-                                    >
-                                        <Trash2 className="h-3.5 w-3.5" />
-                                    </Button>
-                                </div>
-                            </CardContent>
-                        </Card>
-                    ))}
-                </>
-            ) : (
-                <div className="flex flex-col items-center justify-center py-12 text-center space-y-3">
-                    <div className="p-3 rounded-full bg-muted/50">
-                        <Tag className="h-6 w-6 text-muted-foreground/40" />
-                    </div>
-                    <div className="space-y-1">
-                        <p className="text-sm font-medium text-muted-foreground">No points yet</p>
-                        <p className="text-xs text-muted-foreground/60 max-w-[160px]">
-                            Add knowledge points to tag content in this chapter.
-                        </p>
-                    </div>
-                </div>
-            )
-        ) : (
-            <div className="flex flex-col items-center justify-center py-12 text-center text-muted-foreground space-y-2">
-                 <p className="text-sm">Select a chapter to manage knowledge points</p>
-            </div>
-        )}
-        </div>
-      </ScrollArea>
-      
-      <AlertDialog open={showDeleteDialog} onOpenChange={setShowDeleteDialog}>
-        <AlertDialogContent>
-          <AlertDialogHeader>
-            <AlertDialogTitle>Delete Knowledge Point?</AlertDialogTitle>
-            <AlertDialogDescription>
-              This action cannot be undone. This will permanently delete the knowledge point
-              <span className="font-medium text-foreground"> {deleteTarget?.name}</span>.
-            </AlertDialogDescription>
-          </AlertDialogHeader>
-          <AlertDialogFooter>
-            <AlertDialogCancel>Cancel</AlertDialogCancel>
-            <AlertDialogAction onClick={handleDelete} className="bg-destructive text-destructive-foreground hover:bg-destructive/90" disabled={isDeleting}>
-              {isDeleting ? "Deleting..." : "Delete"}
-            </AlertDialogAction>
-          </AlertDialogFooter>
-        </AlertDialogContent>
-      </AlertDialog>
-    </div>
-  )
-}
--- a/src/modules/textbooks/components/section-error-boundary.tsx
+++ b/src/modules/textbooks/components/section-error-boundary.tsx
@@ -0,0 +1,67 @@
+"use client"
+
+/**
+ * 教材模块内联 Error Boundary。
+ *
+ * 用于包裹独立数据区块（章节树、内容区、知识点区、图谱区），
+ * 隔离故障域，避免单点错误导致整个阅读器白屏。
+ */
+
+import { Component, type ReactNode } from "react"
+import { AlertCircle } from "lucide-react"
+import { Button } from "@/shared/components/ui/button"
+
+interface TextbookSectionErrorBoundaryProps {
+  children: ReactNode
+  /** 自定义降级 UI 标题 */
+  fallbackTitle?: string
+  /** 自定义降级 UI 描述 */
+  fallbackDescription?: string
+  /** 重试按钮文案 */
+  retryLabel?: string
+}
+
+interface TextbookSectionErrorBoundaryState {
+  hasError: boolean
+}
+
+export class TextbookSectionErrorBoundary extends Component<
+  TextbookSectionErrorBoundaryProps,
+  TextbookSectionErrorBoundaryState
+> {
+  constructor(props: TextbookSectionErrorBoundaryProps) {
+    super(props)
+    this.state = { hasError: false }
+  }
+
+  static getDerivedStateFromError(): TextbookSectionErrorBoundaryState {
+    return { hasError: true }
+  }
+
+  handleReset = (): void => {
+    this.setState({ hasError: false })
+  }
+
+  render(): ReactNode {
+    if (this.state.hasError) {
+      return (
+        <div className="flex h-full min-h-[200px] flex-col items-center justify-center gap-3 p-6 text-center">
+          <AlertCircle className="h-8 w-8 text-muted-foreground" />
+          <div className="space-y-1">
+            <p className="text-sm font-medium text-foreground">
+              {this.props.fallbackTitle ?? "区块加载失败"}
+            </p>
+            <p className="text-xs text-muted-foreground">
+              {this.props.fallbackDescription ?? "请重试或刷新页面"}
+            </p>
+          </div>
+          <Button size="sm" variant="outline" onClick={this.handleReset}>
+            {this.props.retryLabel ?? "重试"}
+          </Button>
+        </div>
+      )
+    }
+
+    return this.props.children
+  }
+}
--- a/src/modules/textbooks/components/textbook-card.tsx
+++ b/src/modules/textbooks/components/textbook-card.tsx
@@ -1,41 +1,36 @@
-import Link from "next/link";
-import { Book, MoreVertical, Edit, Trash2, BookOpen, GraduationCap, Building2 } from "lucide-react";
+"use client"
+
+import Link from "next/link"
+import { useTranslations } from "next-intl"
+import { Book, MoreVertical, Edit, Trash2, BookOpen, GraduationCap, Building2 } from "lucide-react"
 import {
  Card,
  CardContent,
  CardFooter,
  CardHeader,
-} from "@/shared/components/ui/card";
-import { Badge } from "@/shared/components/ui/badge";
-import { Button } from "@/shared/components/ui/button";
+} from "@/shared/components/ui/card"
+import { Badge } from "@/shared/components/ui/badge"
+import { Button } from "@/shared/components/ui/button"
 import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
-} from "@/shared/components/ui/dropdown-menu";
-import { cn, formatDate } from "@/shared/lib/utils";
-import { Textbook } from "../types";
+} from "@/shared/components/ui/dropdown-menu"
+import { cn, formatDate } from "@/shared/lib/utils"
+import type { Textbook } from "../types"
+import { getSubjectColor } from "../constants"

 interface TextbookCardProps {
-  textbook: Textbook;
-  hrefBase?: string;
-  hideActions?: boolean;
+  textbook: Textbook
+  hrefBase?: string
+  hideActions?: boolean
 }

-const subjectColorMap: Record<string, string> = {
-  Mathematics: "bg-blue-50 text-blue-700 border-blue-200/70 dark:bg-blue-950/50 dark:text-blue-200 dark:border-blue-900/60",
-  Physics: "bg-purple-50 text-purple-700 border-purple-200/70 dark:bg-purple-950/50 dark:text-purple-200 dark:border-purple-900/60",
-  Chemistry: "bg-teal-50 text-teal-700 border-teal-200/70 dark:bg-teal-950/50 dark:text-teal-200 dark:border-teal-900/60",
-  English: "bg-orange-50 text-orange-700 border-orange-200/70 dark:bg-orange-950/50 dark:text-orange-200 dark:border-orange-900/60",
-  History: "bg-amber-50 text-amber-700 border-amber-200/70 dark:bg-amber-950/50 dark:text-amber-200 dark:border-amber-900/60",
-  Biology: "bg-emerald-50 text-emerald-700 border-emerald-200/70 dark:bg-emerald-950/50 dark:text-emerald-200 dark:border-emerald-900/60",
-  Geography: "bg-sky-50 text-sky-700 border-sky-200/70 dark:bg-sky-950/50 dark:text-sky-200 dark:border-sky-900/60",
-};
-
 export function TextbookCard({ textbook, hrefBase, hideActions }: TextbookCardProps) {
-  const base = hrefBase || "/teacher/textbooks";
-  const colorClass = subjectColorMap[textbook.subject] || "bg-zinc-50 text-zinc-700 border-zinc-200/70 dark:bg-zinc-950/50 dark:text-zinc-200 dark:border-zinc-800/70";
+  const t = useTranslations("textbooks")
+  const base = hrefBase || "/teacher/textbooks"
+  const colorClass = getSubjectColor(textbook.subject)

  return (
    <Card className="group flex flex-col h-full overflow-hidden border-border/60 transition-all duration-300 hover:shadow-md hover:border-primary/50">
@@ -50,7 +45,7 @@ export function TextbookCard({ textbook, hrefBase, hideActions }: TextbookCardPr
                <Book className="h-5 w-5" />
              </div>
              <div className="text-xs font-medium text-foreground/70">
-                {textbook.grade || "Grade N/A"}
+                {textbook.grade || t("card.gradeNA")}
              </div>
            </div>
          </div>
@@ -68,54 +63,56 @@ export function TextbookCard({ textbook, hrefBase, hideActions }: TextbookCardPr
          <div className="flex flex-wrap gap-y-1 gap-x-4 text-xs text-muted-foreground">
            <div className="flex items-center gap-1.5">
              <GraduationCap className="h-3.5 w-3.5" />
-              <span>{textbook.grade || "Grade N/A"}</span>
+              <span>{textbook.grade || t("card.gradeNA")}</span>
            </div>
            <div className="flex items-center gap-1.5">
              <Building2 className="h-3.5 w-3.5" />
              <span className="truncate max-w-[120px]" title={textbook.publisher || ""}>
-                {textbook.publisher || "Publisher N/A"}
+                {textbook.publisher || t("card.publisherNA")}
              </span>
            </div>
          </div>
        </CardContent>
      </Link>

-        <CardFooter className="p-4 pt-2 mt-auto border-t border-border/60 bg-muted/30 flex items-center justify-between">
+      <CardFooter className="p-4 pt-2 mt-auto border-t border-border/60 bg-muted/30 flex items-center justify-between">
        <div className="flex items-center gap-2 text-xs text-muted-foreground tabular-nums">
          <div className="flex h-6 w-6 items-center justify-center rounded-full bg-background/80 ring-1 ring-border/60">
            <BookOpen className="h-3.5 w-3.5" />
          </div>
-          <span>{textbook._count?.chapters || 0} Chapters</span>
+          <span>
+            {textbook._count?.chapters || 0} {t("card.chapters")}
+          </span>
        </div>
-        
+
        <div className="flex items-center gap-1">
-           <span className="text-[10px] text-muted-foreground/60 mr-2">
-            Updated {formatDate(textbook.updatedAt)}
-           </span>
-           {!hideActions && (
-             <DropdownMenu>
+          <span className="text-[10px] text-muted-foreground/60 mr-2">
+            {t("card.updated")} {formatDate(textbook.updatedAt)}
+          </span>
+          {!hideActions && (
+            <DropdownMenu>
              <DropdownMenuTrigger asChild>
                <Button variant="ghost" size="icon" className="h-6 w-6 -mr-2">
                  <MoreVertical className="h-3.5 w-3.5" />
-                  <span className="sr-only">More options</span>
+                  <span className="sr-only">{t("card.moreOptions")}</span>
                </Button>
              </DropdownMenuTrigger>
              <DropdownMenuContent align="end">
                <DropdownMenuItem asChild>
-                   <Link href={`${base}/${textbook.id}`}>
-                     <Edit className="mr-2 h-4 w-4" />
-                     Edit Content
-                   </Link>
+                  <Link href={`${base}/${textbook.id}`}>
+                    <Edit className="mr-2 h-4 w-4" />
+                    {t("card.editContent")}
+                  </Link>
                </DropdownMenuItem>
                <DropdownMenuItem className="text-destructive focus:text-destructive">
                  <Trash2 className="mr-2 h-4 w-4" />
-                  Delete
+                  {t("card.delete")}
                </DropdownMenuItem>
              </DropdownMenuContent>
-             </DropdownMenu>
-           )}
+            </DropdownMenu>
+          )}
        </div>
      </CardFooter>
    </Card>
-  );
+  )
 }
--- a/src/modules/textbooks/components/textbook-content-panel.tsx
+++ b/src/modules/textbooks/components/textbook-content-panel.tsx
@@ -5,6 +5,7 @@ import remarkBreaks from "remark-breaks"
 import remarkGfm from "remark-gfm"
 import rehypeSanitize from "rehype-sanitize"
 import { Edit2, Save, Plus } from "lucide-react"
+import { useTranslations } from "next-intl"

 import type { Chapter, KnowledgePoint } from "../types"
 import { cn } from "@/shared/lib/utils"
@@ -63,10 +64,12 @@ export function TextbookContentPanel({
  isSaving,
  processedContent,
 }: TextbookContentPanelProps) {
+  const t = useTranslations("textbooks")
+
  if (!selected) {
    return (
      <div className="flex-1 flex items-center justify-center text-muted-foreground px-2">
-        请选择一个章节开始阅读。
+        {t("reader.selectChapter")}
      </div>
    )
  }
@@ -80,17 +83,17 @@ export function TextbookContentPanel({
            {isEditing ? (
              <>
                <Button size="sm" variant="ghost" onClick={cancelEditing} disabled={isSaving}>
-                  取消
+                  {t("reader.cancel")}
                </Button>
                <Button size="sm" onClick={saveContent} disabled={isSaving}>
                  <Save className="mr-2 h-4 w-4" />
-                  {isSaving ? "保存中..." : "保存"}
+                  {isSaving ? t("reader.saving") : t("reader.save")}
                </Button>
              </>
            ) : (
              <Button size="sm" variant="outline" onClick={startEditing}>
                <Edit2 className="mr-2 h-4 w-4" />
-                编辑内容
+                {t("reader.editContent")}
              </Button>
            )}
          </div>
@@ -135,7 +138,7 @@ export function TextbookContentPanel({
                                  onHighlight(id)
                                  onSwitchToKnowledgeTab()
                                }}
-                                title="点击查看知识点详情"
+                                title={t("reader.clickToViewKp")}
                              >
                                {children}
                              </span>
@@ -149,7 +152,9 @@ export function TextbookContentPanel({
                    </ReactMarkdown>
                  </div>
                ) : (
-                  <div className="text-muted-foreground italic py-8 text-center">暂无内容</div>
+                  <div className="text-muted-foreground italic py-8 text-center">
+                    {t("reader.emptyContent")}
+                  </div>
                )}
              </div>
            </ContextMenuTrigger>
@@ -159,7 +164,7 @@ export function TextbookContentPanel({
                onClick={() => setCreateDialogOpen(true)}
              >
                <Plus className="mr-2 h-4 w-4" />
-                添加知识点
+                {t("reader.addKnowledgePoint")}
              </ContextMenuItem>
            </ContextMenuContent>
          </ContextMenu>
--- a/src/modules/textbooks/components/textbook-filters.tsx
+++ b/src/modules/textbooks/components/textbook-filters.tsx
@@ -1,6 +1,7 @@
 "use client"

 import { useQueryState, parseAsString } from "nuqs"
+import { useTranslations } from "next-intl"

 import {
  Select,
@@ -10,8 +11,10 @@ import {
  SelectValue,
 } from "@/shared/components/ui/select"
 import { FilterBar, FilterSearchInput } from "@/shared/components/ui/filter-bar"
+import { SUBJECTS, GRADES } from "../constants"

 export function TextbookFilters() {
+  const t = useTranslations("textbooks")
  const [search, setSearch] = useQueryState("q", parseAsString.withDefault(""))
  const [subject, setSubject] = useQueryState("subject", parseAsString.withDefault("all"))
  const [grade, setGrade] = useQueryState("grade", parseAsString.withDefault("all"))
@@ -31,38 +34,35 @@ export function TextbookFilters() {
      <FilterSearchInput
        value={search}
        onChange={(v) => setSearch(v || null)}
-        placeholder="Search by title, publisher..."
+        placeholder={t("filters.searchPlaceholder")}
      />

      <div className="flex flex-wrap gap-2 w-full md:w-auto">
        <Select value={subject} onValueChange={(val) => setSubject(val === "all" ? null : val)}>
          <SelectTrigger className="w-[140px] bg-background border-muted-foreground/20">
-            <SelectValue placeholder="Subject" />
+            <SelectValue placeholder={t("field.subject")} />
          </SelectTrigger>
          <SelectContent>
-            <SelectItem value="all">All Subjects</SelectItem>
-            <SelectItem value="Mathematics">Mathematics</SelectItem>
-            <SelectItem value="Physics">Physics</SelectItem>
-            <SelectItem value="Chemistry">Chemistry</SelectItem>
-            <SelectItem value="Biology">Biology</SelectItem>
-            <SelectItem value="English">English</SelectItem>
-            <SelectItem value="History">History</SelectItem>
-            <SelectItem value="Geography">Geography</SelectItem>
+            <SelectItem value="all">{t("filters.allSubjects")}</SelectItem>
+            {SUBJECTS.map((s) => (
+              <SelectItem key={s.value} value={s.value}>
+                {t(`subject.${s.labelKey}`)}
+              </SelectItem>
+            ))}
          </SelectContent>
        </Select>

        <Select value={grade} onValueChange={(val) => setGrade(val === "all" ? null : val)}>
          <SelectTrigger className="w-[130px] bg-background border-muted-foreground/20">
-            <SelectValue placeholder="Grade" />
+            <SelectValue placeholder={t("field.grade")} />
          </SelectTrigger>
          <SelectContent>
-            <SelectItem value="all">All Grades</SelectItem>
-            <SelectItem value="Grade 7">Grade 7</SelectItem>
-            <SelectItem value="Grade 8">Grade 8</SelectItem>
-            <SelectItem value="Grade 9">Grade 9</SelectItem>
-            <SelectItem value="Grade 10">Grade 10</SelectItem>
-            <SelectItem value="Grade 11">Grade 11</SelectItem>
-            <SelectItem value="Grade 12">Grade 12</SelectItem>
+            <SelectItem value="all">{t("filters.allGrades")}</SelectItem>
+            {GRADES.map((g) => (
+              <SelectItem key={g.value} value={g.value}>
+                {t(`grade.${g.labelKey}`)}
+              </SelectItem>
+            ))}
          </SelectContent>
        </Select>
      </div>
--- a/src/modules/textbooks/components/textbook-form-dialog.tsx
+++ b/src/modules/textbooks/components/textbook-form-dialog.tsx
@@ -3,6 +3,7 @@
 import { useState } from "react"
 import { Plus } from "lucide-react"
 import { useFormStatus } from "react-dom"
+import { useTranslations } from "next-intl"
 import { Button } from "@/shared/components/ui/button"
 import {
  Dialog,
@@ -23,22 +24,23 @@ import {
  SelectValue,
 } from "@/shared/components/ui/select"
 import { createTextbookAction } from "../actions"
+import { SUBJECTS, GRADES } from "../constants"
 import { toast } from "sonner"

 function SubmitButton() {
  const { pending } = useFormStatus()
+  const t = useTranslations("textbooks")
  return (
    <Button type="submit" disabled={pending}>
-      {pending ? "Saving..." : "Save changes"}
+      {pending ? t("dialog.create.saving") : t("dialog.create.submit")}
    </Button>
  )
 }

 export function TextbookFormDialog() {
+  const t = useTranslations("textbooks")
  const [open, setOpen] = useState(false)

-  // Using simple form action without useActionState hook for simplicity in this demo environment
-  // In production with React 19/Next 15, we'd use useActionState
  const handleSubmit = async (formData: FormData) => {
    const result = await createTextbookAction(null, formData)
    if (result.success) {
@@ -54,72 +56,70 @@ export function TextbookFormDialog() {
      <DialogTrigger asChild>
        <Button>
          <Plus className="mr-2 h-4 w-4" />
-          Add Textbook
+          {t("list.add")}
        </Button>
      </DialogTrigger>
      <DialogContent className="sm:max-w-[425px]">
        <DialogHeader>
-          <DialogTitle>Add New Textbook</DialogTitle>
-          <DialogDescription>
-            Create a new digital textbook. Click save when you&apos;re done.
-          </DialogDescription>
+          <DialogTitle>{t("dialog.create.title")}</DialogTitle>
+          <DialogDescription>{t("dialog.create.description")}</DialogDescription>
        </DialogHeader>
        <form action={handleSubmit}>
          <div className="grid gap-4 py-4">
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="title" className="text-right">
-                Title
+                {t("field.title")}
              </Label>
              <Input
                id="title"
                name="title"
-                placeholder="e.g. Advanced Calculus"
+                placeholder={t("field.titlePlaceholder")}
                className="col-span-3"
                required
              />
            </div>
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="subject" className="text-right">
-                Subject
+                {t("field.subject")}
              </Label>
              <Select name="subject" required>
                <SelectTrigger className="col-span-3">
-                  <SelectValue placeholder="Select subject" />
+                  <SelectValue placeholder={t("field.subjectPlaceholder")} />
                </SelectTrigger>
                <SelectContent>
-                  <SelectItem value="Mathematics">Mathematics</SelectItem>
-                  <SelectItem value="Physics">Physics</SelectItem>
-                  <SelectItem value="Chemistry">Chemistry</SelectItem>
-                  <SelectItem value="Biology">Biology</SelectItem>
-                  <SelectItem value="English">English</SelectItem>
-                  <SelectItem value="History">History</SelectItem>
-                  <SelectItem value="Geography">Geography</SelectItem>
+                  {SUBJECTS.map((s) => (
+                    <SelectItem key={s.value} value={s.value}>
+                      {t(`subject.${s.labelKey}`)}
+                    </SelectItem>
+                  ))}
                </SelectContent>
              </Select>
            </div>
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="grade" className="text-right">
-                Grade
+                {t("field.grade")}
              </Label>
              <Select name="grade" required>
                <SelectTrigger className="col-span-3">
-                  <SelectValue placeholder="Select grade" />
+                  <SelectValue placeholder={t("field.gradePlaceholder")} />
                </SelectTrigger>
                <SelectContent>
-                  <SelectItem value="Grade 10">Grade 10</SelectItem>
-                  <SelectItem value="Grade 11">Grade 11</SelectItem>
-                  <SelectItem value="Grade 12">Grade 12</SelectItem>
+                  {GRADES.map((g) => (
+                    <SelectItem key={g.value} value={g.value}>
+                      {t(`grade.${g.labelKey}`)}
+                    </SelectItem>
+                  ))}
                </SelectContent>
              </Select>
            </div>
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="publisher" className="text-right">
-                Publisher
+                {t("field.publisher")}
              </Label>
              <Input
                id="publisher"
                name="publisher"
-                placeholder="e.g. Next Education"
+                placeholder={t("field.publisherPlaceholder")}
                className="col-span-3"
              />
            </div>
--- a/src/modules/textbooks/components/textbook-reader.tsx
+++ b/src/modules/textbooks/components/textbook-reader.tsx
@@ -1,12 +1,15 @@
 "use client"

-import { useMemo, useState, useEffect } from "react"
+import { useMemo, useState, useEffect, type ReactNode } from "react"
 import { useQueryState, parseAsString } from "nuqs"
 import { Tag, List, Share2 } from "lucide-react"
+import { useTranslations } from "next-intl"
 import { toast } from "sonner"

 import type { Chapter, KnowledgePoint } from "../types"
 import { updateChapterContentAction } from "../actions"
+import { Permissions } from "@/shared/types/permissions"
+import { usePermission } from "@/shared/hooks/use-permission"
 import { ScrollArea } from "@/shared/components/ui/scroll-area"
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/shared/components/ui/tabs"
 import { Badge } from "@/shared/components/ui/badge"
@@ -25,35 +28,46 @@ import { ChapterSidebarList } from "./chapter-sidebar-list"
 import { KnowledgeGraph } from "./knowledge-graph"
 import { KnowledgePointList } from "./knowledge-point-list"
 import { TextbookContentPanel } from "./textbook-content-panel"
-import { KnowledgePointDialogs } from "./knowledge-point-dialogs"
+import {
+  KnowledgePointDialogs,
+  type QuestionCreatorRenderProps,
+} from "./knowledge-point-dialogs"
+import { TextbookSectionErrorBoundary } from "./section-error-boundary"
 import { useTextSelection } from "../hooks/use-text-selection"
 import { useKnowledgePointActions } from "../hooks/use-knowledge-point-actions"
+import { buildChapterIndex } from "../utils"

-function buildChapterIndex(chapters: Chapter[]) {
-  const index = new Map<string, Chapter>()
-
-  const walk = (nodes: Chapter[]) => {
-    for (const node of nodes) {
-      index.set(node.id, node)
-      if (node.children && node.children.length > 0) walk(node.children)
-    }
-  }
-
-  walk(chapters)
-  return index
+export interface TextbookReaderProps {
+  chapters: Chapter[]
+  knowledgePoints?: KnowledgePoint[]
+  /**
+   * 是否可编辑。已废弃——改由内部 usePermission() 自动判断。
+   * 保留 prop 仅为向后兼容，传入值会被忽略。
+   * @deprecated 改用权限系统自动判断
+   */
+  canEdit?: boolean
+  textbookId?: string
+  /**
+   * 题目创建器渲染函数（P0-1 解耦）。
+   * 由页面层注入 questions 模块的 CreateQuestionDialog 实现。
+   * 不传则不渲染题目创建入口。
+   */
+  renderQuestionCreator?: (props: QuestionCreatorRenderProps) => ReactNode
 }

 export function TextbookReader({
  chapters,
  knowledgePoints = [],
-  canEdit = false,
  textbookId,
-}: {
-  chapters: Chapter[]
-  knowledgePoints?: KnowledgePoint[]
-  canEdit?: boolean
-  textbookId?: string
-}) {
+  renderQuestionCreator,
+}: TextbookReaderProps) {
+  const t = useTranslations("textbooks")
+  const { hasPermission } = usePermission()
+
+  // P0-2 前端权限改由 usePermission 判断，不再接受外部 canEdit 硬编码
+  const canEdit = hasPermission(Permissions.TEXTBOOK_UPDATE)
+  const canCreateQuestion = hasPermission(Permissions.QUESTION_CREATE)
+
  const [chapterId, setChapterId] = useQueryState("chapterId", parseAsString.withDefault(""))
  const [activeTab, setActiveTab] = useState("chapters")
  const [highlightedKpId, setHighlightedKpId] = useState<string | null>(null)
@@ -185,11 +199,11 @@ export function TextbookReader({
            <TabsList className="grid w-full grid-cols-3">
              <TabsTrigger value="chapters" className="gap-2">
                <List className="h-4 w-4" />
-                章节目录
+                {t("reader.tabs.chapters")}
              </TabsTrigger>
              <TabsTrigger value="knowledge" className="gap-2" disabled={!selectedId}>
                <Tag className="h-4 w-4" />
-                知识点
+                {t("reader.tabs.knowledge")}
                {currentChapterKPs.length > 0 && (
                  <Badge variant="secondary" className="ml-1 px-1 py-0 h-5 text-[10px]">
                    {currentChapterKPs.length}
@@ -198,61 +212,80 @@ export function TextbookReader({
              </TabsTrigger>
              <TabsTrigger value="graph" className="gap-2" disabled={!selectedId}>
                <Share2 className="h-4 w-4" />
-                图谱
+                {t("reader.tabs.graph")}
              </TabsTrigger>
            </TabsList>
          </div>

          <TabsContent value="chapters" className="flex-1 min-h-0 mt-0">
-            <ScrollArea className="flex-1 h-full px-2">
-              <div className="space-y-1 pb-4">
-                <ChapterSidebarList
-                  chapters={chapters}
-                  selectedChapterId={selectedId || undefined}
-                  onSelectChapter={handleSelect}
-                  textbookId={textbookId || ""}
-                  canEdit={canEdit}
-                />
-              </div>
-            </ScrollArea>
+            <TextbookSectionErrorBoundary
+              fallbackTitle={t("error.loadFailed")}
+              fallbackDescription={t("error.loadFailedDesc")}
+              retryLabel={t("error.retry")}
+            >
+              <ScrollArea className="flex-1 h-full px-2">
+                <div className="space-y-1 pb-4">
+                  <ChapterSidebarList
+                    chapters={chapters}
+                    selectedChapterId={selectedId || undefined}
+                    onSelectChapter={handleSelect}
+                    textbookId={textbookId || ""}
+                    canEdit={canEdit}
+                  />
+                </div>
+              </ScrollArea>
+            </TextbookSectionErrorBoundary>
          </TabsContent>

          <TabsContent value="knowledge" className="flex-1 min-h-0 mt-0">
-            {!selectedId ? (
-              <div className="flex h-full items-center justify-center text-muted-foreground p-4 text-center text-sm">
-                请选择一个章节查看知识点。
-              </div>
-            ) : (
-              <KnowledgePointList
-                knowledgePoints={currentChapterKPs}
-                canEdit={canEdit}
-                highlightedKpId={highlightedKpId}
-                onHighlight={setHighlightedKpId}
-                onEdit={(kp) => {
-                  setEditingKp(kp)
-                  setEditKpDialogOpen(true)
-                }}
-                onDelete={requestDeleteKnowledgePoint}
-                onCreateQuestion={(kp) => {
-                  setTargetKpForQuestion(kp)
-                  setQuestionDialogOpen(true)
-                }}
-              />
-            )}
+            <TextbookSectionErrorBoundary
+              fallbackTitle={t("error.loadFailed")}
+              fallbackDescription={t("error.loadFailedDesc")}
+              retryLabel={t("error.retry")}
+            >
+              {!selectedId ? (
+                <div className="flex h-full items-center justify-center text-muted-foreground p-4 text-center text-sm">
+                  {t("reader.selectChapterKnowledge")}
+                </div>
+              ) : (
+                <KnowledgePointList
+                  knowledgePoints={currentChapterKPs}
+                  canEdit={canEdit}
+                  canCreateQuestion={canCreateQuestion}
+                  highlightedKpId={highlightedKpId}
+                  onHighlight={setHighlightedKpId}
+                  onEdit={(kp) => {
+                    setEditingKp(kp)
+                    setEditKpDialogOpen(true)
+                  }}
+                  onDelete={requestDeleteKnowledgePoint}
+                  onCreateQuestion={(kp) => {
+                    setTargetKpForQuestion(kp)
+                    setQuestionDialogOpen(true)
+                  }}
+                />
+              )}
+            </TextbookSectionErrorBoundary>
          </TabsContent>

          <TabsContent value="graph" className="flex-1 min-h-0 mt-0">
-            {!selectedId ? (
-              <div className="flex h-full items-center justify-center text-muted-foreground p-4 text-center text-sm">
-                请选择一个章节查看知识图谱。
-              </div>
-            ) : (
-              <KnowledgeGraph
-                knowledgePoints={currentChapterKPs}
-                selectedId={highlightedKpId}
-                onHighlight={setHighlightedKpId}
-              />
-            )}
+            <TextbookSectionErrorBoundary
+              fallbackTitle={t("error.loadFailed")}
+              fallbackDescription={t("error.loadFailedDesc")}
+              retryLabel={t("error.retry")}
+            >
+              {!selectedId ? (
+                <div className="flex h-full items-center justify-center text-muted-foreground p-4 text-center text-sm">
+                  {t("reader.selectChapterGraph")}
+                </div>
+              ) : (
+                <KnowledgeGraph
+                  knowledgePoints={currentChapterKPs}
+                  selectedId={highlightedKpId}
+                  onHighlight={setHighlightedKpId}
+                />
+              )}
+            </TextbookSectionErrorBoundary>
          </TabsContent>
        </Tabs>
      </div>
@@ -261,14 +294,14 @@ export function TextbookReader({
        <AlertDialog open={deleteConfirmOpen} onOpenChange={setDeleteConfirmOpen}>
          <AlertDialogContent>
            <AlertDialogHeader>
-              <AlertDialogTitle>确认删除</AlertDialogTitle>
-              <AlertDialogDescription>
-                确定要删除这个知识点吗？此操作无法撤销。
-              </AlertDialogDescription>
+              <AlertDialogTitle>{t("dialog.knowledge.deleteTitle")}</AlertDialogTitle>
+              <AlertDialogDescription>{t("dialog.knowledge.deleteDesc")}</AlertDialogDescription>
            </AlertDialogHeader>
            <AlertDialogFooter>
-              <AlertDialogCancel>取消</AlertDialogCancel>
-              <AlertDialogAction onClick={confirmDeleteKnowledgePoint}>删除</AlertDialogAction>
+              <AlertDialogCancel>{t("dialog.knowledge.cancel")}</AlertDialogCancel>
+              <AlertDialogAction onClick={confirmDeleteKnowledgePoint}>
+                {t("dialog.knowledge.delete")}
+              </AlertDialogAction>
            </AlertDialogFooter>
          </AlertDialogContent>
        </AlertDialog>
@@ -287,32 +320,39 @@ export function TextbookReader({
          questionDialogOpen={questionDialogOpen}
          setQuestionDialogOpen={setQuestionDialogOpen}
          targetKpForQuestion={targetKpForQuestion}
+          renderQuestionCreator={canCreateQuestion ? renderQuestionCreator : undefined}
        />

-        <TextbookContentPanel
-          selected={selected}
-          isEditing={isEditing}
-          editContent={editContent}
-          setEditContent={setEditContent}
-          canEdit={canEdit}
-          knowledgePoints={currentChapterKPs}
-          highlightedKpId={highlightedKpId}
-          onHighlight={setHighlightedKpId}
-          onSwitchToKnowledgeTab={() => setActiveTab("knowledge")}
-          contentRef={contentRef}
-          onPointerDown={handleContentPointerDown}
-          onContextMenuChange={handleContextMenuChange}
-          selectedText={selectedText}
-          createDialogOpen={createDialogOpen}
-          setCreateDialogOpen={setCreateDialogOpen}
-          isCreating={isCreating}
-          onCreateKnowledgePoint={onCreateKnowledgePoint}
-          startEditing={startEditing}
-          cancelEditing={() => setIsEditing(false)}
-          saveContent={handleSaveContent}
-          isSaving={isSaving}
-          processedContent={processedContent}
-        />
+        <TextbookSectionErrorBoundary
+          fallbackTitle={t("error.loadFailed")}
+          fallbackDescription={t("error.loadFailedDesc")}
+          retryLabel={t("error.retry")}
+        >
+          <TextbookContentPanel
+            selected={selected}
+            isEditing={isEditing}
+            editContent={editContent}
+            setEditContent={setEditContent}
+            canEdit={canEdit}
+            knowledgePoints={currentChapterKPs}
+            highlightedKpId={highlightedKpId}
+            onHighlight={setHighlightedKpId}
+            onSwitchToKnowledgeTab={() => setActiveTab("knowledge")}
+            contentRef={contentRef}
+            onPointerDown={handleContentPointerDown}
+            onContextMenuChange={handleContextMenuChange}
+            selectedText={selectedText}
+            createDialogOpen={createDialogOpen}
+            setCreateDialogOpen={setCreateDialogOpen}
+            isCreating={isCreating}
+            onCreateKnowledgePoint={onCreateKnowledgePoint}
+            startEditing={startEditing}
+            cancelEditing={() => setIsEditing(false)}
+            saveContent={handleSaveContent}
+            isSaving={isSaving}
+            processedContent={processedContent}
+          />
+        </TextbookSectionErrorBoundary>
      </div>
    </div>
  )
--- a/src/modules/textbooks/components/textbook-settings-dialog.tsx
+++ b/src/modules/textbooks/components/textbook-settings-dialog.tsx
@@ -3,6 +3,7 @@
 import { useState } from "react"
 import { Edit } from "lucide-react"
 import { useRouter } from "next/navigation"
+import { useTranslations } from "next-intl"
 import { Button } from "@/shared/components/ui/button"
 import {
  Dialog,
@@ -13,6 +14,16 @@ import {
  DialogTitle,
  DialogTrigger,
 } from "@/shared/components/ui/dialog"
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from "@/shared/components/ui/alert-dialog"
 import { Input } from "@/shared/components/ui/input"
 import { Label } from "@/shared/components/ui/label"
 import {
@@ -23,8 +34,9 @@ import {
  SelectValue,
 } from "@/shared/components/ui/select"
 import { updateTextbookAction, deleteTextbookAction } from "../actions"
+import { SUBJECTS, GRADES } from "../constants"
 import { toast } from "sonner"
-import { Textbook } from "../types"
+import type { Textbook } from "../types"

 interface TextbookSettingsDialogProps {
  textbook: Textbook
@@ -32,8 +44,10 @@ interface TextbookSettingsDialogProps {
 }

 export function TextbookSettingsDialog({ textbook, trigger }: TextbookSettingsDialogProps) {
+  const t = useTranslations("textbooks")
  const [open, setOpen] = useState(false)
  const [loading, setLoading] = useState(false)
+  const [deleteDialogOpen, setDeleteDialogOpen] = useState(false)
  const router = useRouter()

  const handleUpdate = async (formData: FormData) => {
@@ -48,15 +62,15 @@ export function TextbookSettingsDialog({ textbook, trigger }: TextbookSettingsDi
    }
  }

+  // P1-8 用 AlertDialog 替换浏览器原生 confirm()
  const handleDelete = async () => {
-    if (!confirm("Are you sure you want to delete this textbook? This action cannot be undone.")) return
-    
+    setDeleteDialogOpen(false)
    setLoading(true)
    const result = await deleteTextbookAction(textbook.id)
-    
+
    if (result.success) {
      toast.success(result.message)
-      router.push("/teacher/textbooks") // Redirect after delete
+      router.push("/teacher/textbooks")
    } else {
      setLoading(false)
      toast.error(result.message)
@@ -69,23 +83,21 @@ export function TextbookSettingsDialog({ textbook, trigger }: TextbookSettingsDi
        {trigger || (
          <Button variant="outline" size="sm">
            <Edit className="mr-2 h-4 w-4" />
-            Settings
+            {t("dialog.settings.trigger")}
          </Button>
        )}
      </DialogTrigger>
      <DialogContent className="sm:max-w-[425px]">
        <DialogHeader>
-          <DialogTitle>Textbook Settings</DialogTitle>
-          <DialogDescription>
-            Update textbook details or delete this textbook.
-          </DialogDescription>
+          <DialogTitle>{t("dialog.settings.title")}</DialogTitle>
+          <DialogDescription>{t("dialog.settings.description")}</DialogDescription>
        </DialogHeader>
-        
+
        <form action={handleUpdate}>
          <div className="grid gap-4 py-4">
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="title" className="text-right">
-                Title
+                {t("field.title")}
              </Label>
              <Input
                id="title"
@@ -97,39 +109,41 @@ export function TextbookSettingsDialog({ textbook, trigger }: TextbookSettingsDi
            </div>
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="subject" className="text-right">
-                Subject
+                {t("field.subject")}
              </Label>
              <Select name="subject" defaultValue={textbook.subject} required>
                <SelectTrigger className="col-span-3">
-                  <SelectValue placeholder="Select subject" />
+                  <SelectValue placeholder={t("field.subjectPlaceholder")} />
                </SelectTrigger>
                <SelectContent>
-                  <SelectItem value="Mathematics">Mathematics</SelectItem>
-                  <SelectItem value="Physics">Physics</SelectItem>
-                  <SelectItem value="History">History</SelectItem>
-                  <SelectItem value="English">English</SelectItem>
-                  <SelectItem value="Chemistry">Chemistry</SelectItem>
+                  {SUBJECTS.map((s) => (
+                    <SelectItem key={s.value} value={s.value}>
+                      {t(`subject.${s.labelKey}`)}
+                    </SelectItem>
+                  ))}
                </SelectContent>
              </Select>
            </div>
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="grade" className="text-right">
-                Grade
+                {t("field.grade")}
              </Label>
              <Select name="grade" defaultValue={textbook.grade || undefined} required>
                <SelectTrigger className="col-span-3">
-                  <SelectValue placeholder="Select grade" />
+                  <SelectValue placeholder={t("field.gradePlaceholder")} />
                </SelectTrigger>
                <SelectContent>
-                  <SelectItem value="Grade 10">Grade 10</SelectItem>
-                  <SelectItem value="Grade 11">Grade 11</SelectItem>
-                  <SelectItem value="Grade 12">Grade 12</SelectItem>
+                  {GRADES.map((g) => (
+                    <SelectItem key={g.value} value={g.value}>
+                      {t(`grade.${g.labelKey}`)}
+                    </SelectItem>
+                  ))}
                </SelectContent>
              </Select>
            </div>
            <div className="grid grid-cols-4 items-center gap-4">
              <Label htmlFor="publisher" className="text-right">
-                Publisher
+                {t("field.publisher")}
              </Label>
              <Input
                id="publisher"
@@ -139,22 +153,39 @@ export function TextbookSettingsDialog({ textbook, trigger }: TextbookSettingsDi
              />
            </div>
          </div>
-          
+
          <DialogFooter className="flex justify-between sm:justify-between">
-             <Button 
-                type="button" 
-                variant="destructive" 
-                onClick={handleDelete}
-                disabled={loading}
-             >
-                {loading ? "Processing..." : "Delete Textbook"}
-             </Button>
-             <Button type="submit" disabled={loading}>
-                {loading ? "Saving..." : "Save Changes"}
-             </Button>
+            <Button
+              type="button"
+              variant="destructive"
+              onClick={() => setDeleteDialogOpen(true)}
+              disabled={loading}
+            >
+              {loading ? t("dialog.settings.processing") : t("dialog.settings.delete")}
+            </Button>
+            <Button type="submit" disabled={loading}>
+              {loading ? t("dialog.settings.processing") : t("dialog.settings.save")}
+            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
+
+      <AlertDialog open={deleteDialogOpen} onOpenChange={setDeleteDialogOpen}>
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>{t("dialog.settings.deleteConfirmTitle")}</AlertDialogTitle>
+            <AlertDialogDescription>
+              {t("dialog.settings.deleteConfirmDesc")}
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>{t("dialog.knowledge.cancel")}</AlertDialogCancel>
+            <AlertDialogAction onClick={handleDelete}>
+              {t("dialog.settings.delete")}
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
    </Dialog>
  )
 }
--- a/src/modules/textbooks/constants.ts
+++ b/src/modules/textbooks/constants.ts
@@ -0,0 +1,75 @@
+/**
+ * 教材模块共享常量。
+ *
+ * 集中管理学科、年级、学科颜色映射，避免在 filters/form/settings/card 多处硬编码导致不一致。
+ */
+
+export type SubjectOption = {
+  /** 存储值（英文 key，写入数据库） */
+  value: string
+  /** i18n 键（用于翻译显示） */
+  labelKey: string
+}
+
+export type GradeOption = {
+  value: string
+  labelKey: string
+}
+
+/**
+ * 学科列表。
+ * 新增学科只需在此处添加一条记录，所有 Select/筛选/表单/设置弹窗自动同步。
+ */
+export const SUBJECTS: readonly SubjectOption[] = [
+  { value: "Mathematics", labelKey: "mathematics" },
+  { value: "Physics", labelKey: "physics" },
+  { value: "Chemistry", labelKey: "chemistry" },
+  { value: "Biology", labelKey: "biology" },
+  { value: "English", labelKey: "english" },
+  { value: "History", labelKey: "history" },
+  { value: "Geography", labelKey: "geography" },
+] as const
+
+/**
+ * 年级列表。
+ */
+export const GRADES: readonly GradeOption[] = [
+  { value: "Grade 7", labelKey: "grade7" },
+  { value: "Grade 8", labelKey: "grade8" },
+  { value: "Grade 9", labelKey: "grade9" },
+  { value: "Grade 10", labelKey: "grade10" },
+  { value: "Grade 11", labelKey: "grade11" },
+  { value: "Grade 12", labelKey: "grade12" },
+] as const
+
+/**
+ * 学科主题色映射（用于教材卡片封面背景）。
+ * key 必须与 SUBJECTS 中的 value 一致。
+ */
+export const SUBJECT_COLORS: Record<string, string> = {
+  Mathematics:
+    "bg-blue-50 text-blue-700 border-blue-200/70 dark:bg-blue-950/50 dark:text-blue-200 dark:border-blue-900/60",
+  Physics:
+    "bg-purple-50 text-purple-700 border-purple-200/70 dark:bg-purple-950/50 dark:text-purple-200 dark:border-purple-900/60",
+  Chemistry:
+    "bg-teal-50 text-teal-700 border-teal-200/70 dark:bg-teal-950/50 dark:text-teal-200 dark:border-teal-900/60",
+  English:
+    "bg-orange-50 text-orange-700 border-orange-200/70 dark:bg-orange-950/50 dark:text-orange-200 dark:border-orange-900/60",
+  History:
+    "bg-amber-50 text-amber-700 border-amber-200/70 dark:bg-amber-950/50 dark:text-amber-200 dark:border-amber-900/60",
+  Biology:
+    "bg-emerald-50 text-emerald-700 border-emerald-200/70 dark:bg-emerald-950/50 dark:text-emerald-200 dark:border-emerald-900/60",
+  Geography:
+    "bg-sky-50 text-sky-700 border-sky-200/70 dark:bg-sky-950/50 dark:text-sky-200 dark:border-sky-900/60",
+}
+
+/** 默认学科色（未命中 SUBJECT_COLORS 时的兜底） */
+export const DEFAULT_SUBJECT_COLOR =
+  "bg-zinc-50 text-zinc-700 border-zinc-200/70 dark:bg-zinc-950/50 dark:text-zinc-200 dark:border-zinc-800/70"
+
+/**
+ * 根据学科 value 获取主题色 className。
+ */
+export function getSubjectColor(subject: string): string {
+  return SUBJECT_COLORS[subject] ?? DEFAULT_SUBJECT_COLOR
+}
--- a/src/modules/textbooks/data-access.ts
+++ b/src/modules/textbooks/data-access.ts
@@ -19,57 +19,21 @@ import type {
  UpdateKnowledgePointInput,
  UpdateTextbookInput,
 } from "./schema"
+import {
+  buildChapterTree,
+  normalizeOptional,
+  sortChapters,
+} from "./utils"

-const normalizeOptional = (v: string | null | undefined): string | null => {
-  const trimmed = v?.trim()
-  if (!trimmed) return null
-  return trimmed
-}
+export { buildChapterTree, normalizeOptional, sortChapters }

-const sortChapters = (a: Chapter, b: Chapter): number => {
-  const ao = a.order ?? 0
-  const bo = b.order ?? 0
-  if (ao !== bo) return ao - bo
-  return a.title.localeCompare(b.title)
-}
-
-const buildChapterTree = (rows: Chapter[]): Chapter[] => {
-  type ChapterNode = Chapter & { children: ChapterNode[] }
-
-  const isChapterNode = (n: Chapter): n is ChapterNode =>
-    Array.isArray(n.children)
-
-  const byId = new Map<string, ChapterNode>()
-  for (const ch of rows) {
-    byId.set(ch.id, { ...ch, children: [] })
-  }
-
-  const roots: ChapterNode[] = []
-  for (const ch of byId.values()) {
-    const pid = ch.parentId
-    if (pid) {
-      const parent = byId.get(pid)
-      if (parent) {
-        parent.children.push(ch)
-      } else {
-        roots.push(ch)
-      }
-    } else {
-      roots.push(ch)
-    }
-  }
-
-  const sortRecursive = (nodes: ChapterNode[]) => {
-    nodes.sort(sortChapters)
-    for (const n of nodes) {
-      if (isChapterNode(n)) {
-        sortRecursive(n.children)
-      }
-    }
-  }
-
-  sortRecursive(roots)
-  return roots
+/**
+ * 数据范围过滤参数。
+ * 学生端应传入 grade 按年级过滤；教师/admin 端不传则返回全量。
+ */
+export interface TextbookQueryScope {
+  /** 按年级过滤（学生端传入学生所在年级） */
+  grade?: string
 }

 export const getTextbooks = cache(async (query?: string, subject?: string, grade?: string): Promise<Textbook[]> => {
@@ -459,6 +423,147 @@ export const getTextbooksDashboardStats = cache(async (): Promise<TextbooksDashb
  }
 })

+// ---------------------------------------------------------------------------
+// 资源归属校验（P0-4）
+// ---------------------------------------------------------------------------
+
+/**
+ * 校验章节是否属于指定教材。
+ *
+ * 用于 Server Action 二次校验，防止越权操作其他教材的章节。
+ *
+ * @returns true 表示归属一致
+ */
+export async function verifyChapterBelongsToTextbook(
+  chapterId: string,
+  textbookId: string
+): Promise<boolean> {
+  const [row] = await db
+    .select({ textbookId: chapters.textbookId })
+    .from(chapters)
+    .where(eq(chapters.id, chapterId))
+    .limit(1)
+
+  if (!row) return false
+  return row.textbookId === textbookId
+}
+
+/**
+ * 校验知识点是否属于指定章节。
+ */
+export async function verifyKnowledgePointBelongsToChapter(
+  kpId: string,
+  chapterId: string
+): Promise<boolean> {
+  const [row] = await db
+    .select({ chapterId: knowledgePoints.chapterId })
+    .from(knowledgePoints)
+    .where(eq(knowledgePoints.id, kpId))
+    .limit(1)
+
+  if (!row) return false
+  return row.chapterId === chapterId
+}
+
+/**
+ * 校验知识点是否属于指定教材（通过 chapter → textbook 关联）。
+ *
+ * 用于 Server Action 二次校验，防止越权操作其他教材的知识点。
+ */
+export async function verifyKnowledgePointBelongsToTextbook(
+  kpId: string,
+  textbookId: string
+): Promise<boolean> {
+  const [row] = await db
+    .select({ textbookId: chapters.textbookId })
+    .from(knowledgePoints)
+    .innerJoin(chapters, eq(chapters.id, knowledgePoints.chapterId))
+    .where(eq(knowledgePoints.id, kpId))
+    .limit(1)
+
+  if (!row) return false
+  return row.textbookId === textbookId
+}
+
+// ---------------------------------------------------------------------------
+// 带 scope 的查询（P1-1 数据范围过滤）
+// ---------------------------------------------------------------------------
+
+/**
+ * 按数据范围获取教材列表。
+ *
+ * 学生端应传入 `scope.grade` 按年级过滤，避免跨年级越权读取。
+ */
+export const getTextbooksWithScope = cache(
+  async (
+    query?: string,
+    subject?: string,
+    grade?: string,
+    scope?: TextbookQueryScope
+  ): Promise<Textbook[]> => {
+    const conditions: SQL[] = []
+
+    const q = query?.trim()
+    if (q) {
+      const needle = `%${q}%`
+      const nameCond = or(
+        like(textbooks.title, needle),
+        like(textbooks.subject, needle),
+        like(textbooks.grade, needle),
+        like(textbooks.publisher, needle)
+      )
+      if (nameCond) conditions.push(nameCond)
+    }
+
+    const s = subject?.trim()
+    if (s && s !== "all") conditions.push(eq(textbooks.subject, s))
+
+    // URL 参数 grade（用户筛选）
+    const g = grade?.trim()
+    if (g && g !== "all") conditions.push(eq(textbooks.grade, g))
+
+    // scope.grade（数据范围过滤，学生端强制按年级过滤）
+    const scopeGrade = scope?.grade?.trim()
+    if (scopeGrade) conditions.push(eq(textbooks.grade, scopeGrade))
+
+    const rows = await db
+      .select({
+        id: textbooks.id,
+        title: textbooks.title,
+        subject: textbooks.subject,
+        grade: textbooks.grade,
+        publisher: textbooks.publisher,
+        createdAt: textbooks.createdAt,
+        updatedAt: textbooks.updatedAt,
+        chaptersCount: sql<number>`COUNT(${chapters.id})`,
+      })
+      .from(textbooks)
+      .leftJoin(chapters, eq(chapters.textbookId, textbooks.id))
+      .where(conditions.length ? and(...conditions) : undefined)
+      .groupBy(
+        textbooks.id,
+        textbooks.title,
+        textbooks.subject,
+        textbooks.grade,
+        textbooks.publisher,
+        textbooks.createdAt,
+        textbooks.updatedAt
+      )
+      .orderBy(asc(textbooks.title), asc(textbooks.subject), asc(textbooks.grade))
+
+    return rows.map((r) => ({
+      id: r.id,
+      title: r.title,
+      subject: r.subject,
+      grade: r.grade,
+      publisher: r.publisher,
+      createdAt: r.createdAt,
+      updatedAt: r.updatedAt,
+      _count: { chapters: Number(r.chaptersCount ?? 0) },
+    }))
+  }
+)
+
 // ---------------------------------------------------------------------------
 // Cross-module query interfaces — read-only access for other modules
 // ---------------------------------------------------------------------------
--- a/src/modules/textbooks/graph-layout.test.ts
+++ b/src/modules/textbooks/graph-layout.test.ts
@@ -0,0 +1,95 @@
+import { describe, it, expect } from "vitest"
+import type { KnowledgePoint } from "./types"
+import { computeGraphLayout, NODE_WIDTH, NODE_HEIGHT, GAP_X, GAP_Y } from "./graph-layout"
+
+describe("textbooks/graph-layout", () => {
+  const makeKp = (id: string, parentId: string | null = null): KnowledgePoint => ({
+    id,
+    name: `KP-${id}`,
+    chapterId: "c1",
+    parentId,
+    level: 1,
+    order: 0,
+  })
+
+  describe("computeGraphLayout", () => {
+    it("should return empty layout for empty input", () => {
+      const layout = computeGraphLayout([])
+      expect(layout.nodes).toEqual([])
+      expect(layout.edges).toEqual([])
+      expect(layout.width).toBe(0)
+      expect(layout.height).toBe(0)
+    })
+
+    it("should place single root node", () => {
+      const layout = computeGraphLayout([makeKp("1")])
+      expect(layout.nodes).toHaveLength(1)
+      expect(layout.nodes[0].x).toBe(GAP_X)
+      expect(layout.nodes[0].y).toBe(GAP_Y)
+      expect(layout.edges).toHaveLength(0)
+    })
+
+    it("should compute parent-child layout with edge", () => {
+      const layout = computeGraphLayout([makeKp("1"), makeKp("2", "1")])
+      expect(layout.nodes).toHaveLength(2)
+      expect(layout.edges).toHaveLength(1)
+      expect(layout.edges[0].id).toBe("1-2")
+    })
+
+    it("should place children at lower level (higher y)", () => {
+      const layout = computeGraphLayout([makeKp("1"), makeKp("2", "1")])
+      const root = layout.nodes.find((n) => n.id === "1")
+      const child = layout.nodes.find((n) => n.id === "2")
+      expect(child!.y).toBeGreaterThan(root!.y)
+    })
+
+    it("should handle multiple roots", () => {
+      const layout = computeGraphLayout([makeKp("1"), makeKp("2")])
+      expect(layout.nodes).toHaveLength(2)
+      expect(layout.edges).toHaveLength(0)
+      const n1 = layout.nodes.find((n) => n.id === "1")
+      const n2 = layout.nodes.find((n) => n.id === "2")
+      expect(n2!.x).toBeGreaterThan(n1!.x)
+    })
+
+    it("should handle circular references gracefully (no infinite loop)", () => {
+      // a → b → a 循环
+      const kps = [makeKp("a", "b"), makeKp("b", "a")]
+      const layout = computeGraphLayout(kps)
+      expect(layout.nodes).toHaveLength(2)
+    })
+
+    it("should handle all nodes referencing non-existent parent", () => {
+      const kps = [makeKp("1", "nonexistent"), makeKp("2", "nonexistent")]
+      const layout = computeGraphLayout(kps)
+      expect(layout.nodes).toHaveLength(2)
+      // 全部作为根节点处理
+      expect(layout.edges).toHaveLength(0)
+    })
+
+    it("should compute width based on max nodes per level", () => {
+      const kps = [
+        makeKp("1"),
+        makeKp("2"),
+        makeKp("3"),
+        makeKp("4", "1"),
+      ]
+      const layout = computeGraphLayout(kps)
+      // 第 0 层有 3 个节点，是最大层
+      const expectedWidth = 3 * (NODE_WIDTH + GAP_X) + GAP_X
+      expect(layout.width).toBe(expectedWidth)
+    })
+
+    it("should compute height based on level count", () => {
+      const kps = [
+        makeKp("1"),
+        makeKp("2", "1"),
+        makeKp("3", "2"),
+      ]
+      const layout = computeGraphLayout(kps)
+      // 3 层
+      const expectedHeight = 3 * (NODE_HEIGHT + GAP_Y) + GAP_Y
+      expect(layout.height).toBe(expectedHeight)
+    })
+  })
+})
--- a/src/modules/textbooks/graph-layout.ts
+++ b/src/modules/textbooks/graph-layout.ts
@@ -0,0 +1,141 @@
+/**
+ * 知识图谱布局纯函数。
+ *
+ * 从 knowledge-graph.tsx 抽离，便于单元测试。
+ */
+
+import type { KnowledgePoint } from "./types"
+
+export interface GraphNode extends KnowledgePoint {
+  x: number
+  y: number
+}
+
+export interface GraphEdge {
+  id: string
+  x1: number
+  y1: number
+  x2: number
+  y2: number
+}
+
+export interface GraphLayout {
+  nodes: GraphNode[]
+  edges: GraphEdge[]
+  width: number
+  height: number
+}
+
+/** 节点尺寸常量 */
+export const NODE_WIDTH = 160
+export const NODE_HEIGHT = 52
+export const GAP_X = 40
+export const GAP_Y = 90
+
+/**
+ * 计算知识图谱的分层布局。
+ *
+ * 算法：
+ * 1. 根据 parentId 构建父子关系
+ * 2. BFS 计算每个节点的层级（level）
+ * 3. 同层节点按出现顺序水平排列
+ * 4. 生成节点坐标和边坐标
+ *
+ * @param knowledgePoints 知识点列表
+ * @returns 图布局（节点带坐标、边、总宽高）
+ */
+export function computeGraphLayout(
+  knowledgePoints: KnowledgePoint[]
+): GraphLayout {
+  if (knowledgePoints.length === 0) {
+    return { nodes: [], edges: [], width: 0, height: 0 }
+  }
+
+  const byId = new Map<string, KnowledgePoint>()
+  for (const kp of knowledgePoints) byId.set(kp.id, kp)
+
+  const children = new Map<string, string[]>()
+  const roots: string[] = []
+
+  for (const kp of knowledgePoints) {
+    if (kp.parentId && byId.has(kp.parentId)) {
+      const arr = children.get(kp.parentId) ?? []
+      arr.push(kp.id)
+      children.set(kp.parentId, arr)
+    } else {
+      roots.push(kp.id)
+    }
+  }
+
+  const levelMap = new Map<string, number>()
+  const levels: string[][] = []
+  const queue = [...roots].map((id) => ({ id, level: 0 }))
+
+  // 容错：如果没有任何根节点（全部循环引用），把所有节点放第 0 层
+  if (queue.length === 0) {
+    for (const kp of knowledgePoints) queue.push({ id: kp.id, level: 0 })
+  }
+
+  while (queue.length > 0) {
+    const item = queue.shift()
+    if (!item) continue
+    if (levelMap.has(item.id)) continue
+    levelMap.set(item.id, item.level)
+    if (!levels[item.level]) levels[item.level] = []
+    levels[item.level].push(item.id)
+    const kids = children.get(item.id) ?? []
+    for (const kid of kids) {
+      if (!levelMap.has(kid)) queue.push({ id: kid, level: item.level + 1 })
+    }
+  }
+
+  // 容错：处理孤立节点（未在 BFS 中访问到）
+  for (const kp of knowledgePoints) {
+    if (!levelMap.has(kp.id)) {
+      const level = levels.length
+      levelMap.set(kp.id, level)
+      if (!levels[level]) levels[level] = []
+      levels[level].push(kp.id)
+    }
+  }
+
+  const maxCount = Math.max(...levels.map((l) => l.length), 1)
+  const width = maxCount * (NODE_WIDTH + GAP_X) + GAP_X
+  const height = levels.length * (NODE_HEIGHT + GAP_Y) + GAP_Y
+
+  const positions = new Map<string, { x: number; y: number }>()
+  levels.forEach((ids, level) => {
+    ids.forEach((id, index) => {
+      const x = GAP_X + index * (NODE_WIDTH + GAP_X)
+      const y = GAP_Y + level * (NODE_HEIGHT + GAP_Y)
+      positions.set(id, { x, y })
+    })
+  })
+
+  const nodes = knowledgePoints.map((kp) => {
+    const pos = positions.get(kp.id) ?? { x: GAP_X, y: GAP_Y }
+    return { ...kp, x: pos.x, y: pos.y }
+  })
+
+  const edges = knowledgePoints
+    .filter((kp) => kp.parentId && positions.has(kp.parentId))
+    .map((kp) => {
+      const parentId = kp.parentId as string
+      const parentPos = positions.get(parentId)
+      const childPos = positions.get(kp.id)
+      // 类型守卫：两个位置都必须存在（已在 filter 中保证，但 TS 需要 narrowing）
+      if (!parentPos || !childPos) {
+        return null
+      }
+      return {
+        id: `${parentId}-${kp.id}`,
+        x1: parentPos.x + NODE_WIDTH / 2,
+        y1: parentPos.y + NODE_HEIGHT,
+        x2: childPos.x + NODE_WIDTH / 2,
+        y2: childPos.y,
+      }
+    })
+    .filter((e): e is GraphEdge => e !== null)
+
+  return { nodes, edges, width, height }
+}
--- a/src/modules/textbooks/hooks/use-knowledge-point-actions.ts
+++ b/src/modules/textbooks/hooks/use-knowledge-point-actions.ts
@@ -1,6 +1,7 @@
 "use client"

 import { useState } from "react"
+import { useTranslations } from "next-intl"
 import { toast } from "sonner"

 import type { KnowledgePoint } from "../types"
@@ -18,6 +19,7 @@ export function useKnowledgePointActions(
  setHighlightedKpId: (id: string | null) => void,
  onKpCreated?: () => void,
 ) {
+  const t = useTranslations("textbooks")
  const [editingKp, setEditingKp] = useState<KnowledgePoint | null>(null)
  const [editKpDialogOpen, setEditKpDialogOpen] = useState(false)
  const [isUpdatingKp, setIsUpdatingKp] = useState(false)
@@ -37,16 +39,16 @@ export function useKnowledgePointActions(
      )

      if (result.success) {
-        toast.success("知识点已创建")
+        toast.success(t("action.kpCreateSuccess"))
        onKpCreated?.()
        window.getSelection()?.removeAllRanges()
        return true
      } else {
-        toast.error(result.message || "创建知识点失败")
+        toast.error(result.message || t("action.kpCreateFailed"))
        return false
      }
    } catch {
-      toast.error("发生错误")
+      toast.error(t("action.errorOccurred"))
      return false
    }
  }
@@ -75,7 +77,7 @@ export function useKnowledgePointActions(
        toast.error(result.message)
      }
    } catch {
-      toast.error("删除失败")
+      toast.error(t("action.deleteFailed"))
    } finally {
      setPendingDeleteKpId(null)
    }
@@ -95,7 +97,7 @@ export function useKnowledgePointActions(
        toast.error(result.message)
      }
    } catch {
-      toast.error("更新失败")
+      toast.error(t("action.updateFailedGeneric"))
    } finally {
      setIsUpdatingKp(false)
    }
--- a/src/modules/textbooks/utils.test.ts
+++ b/src/modules/textbooks/utils.test.ts
@@ -0,0 +1,181 @@
+import { describe, it, expect } from "vitest"
+import type { Chapter, KnowledgePoint } from "./types"
+import {
+  buildChapterTree,
+  buildChapterIndex,
+  findChapterParent,
+  filterKnowledgePointsByChapter,
+  normalizeOptional,
+  sortChapters,
+} from "./utils"
+
+// 测试辅助：构造最小合法 Chapter（补齐 createdAt/updatedAt 等必填字段）
+const makeChapter = (over: Partial<Chapter> & Pick<Chapter, "id" | "title" | "textbookId">): Chapter => ({
+  order: 0,
+  parentId: null,
+  content: null,
+  createdAt: new Date(0),
+  updatedAt: new Date(0),
+  ...over,
+})
+
+describe("textbooks/utils", () => {
+  describe("sortChapters", () => {
+    it("should sort by order ascending", () => {
+      const a = makeChapter({ id: "1", title: "A", order: 2, textbookId: "t1" })
+      const b = makeChapter({ id: "2", title: "B", order: 1, textbookId: "t1" })
+      expect(sortChapters(a, b)).toBeGreaterThan(0)
+    })
+
+    it("should fall back to title localeCompare when order equal", () => {
+      const a = makeChapter({ id: "1", title: "Banana", order: 1, textbookId: "t1" })
+      const b = makeChapter({ id: "2", title: "Apple", order: 1, textbookId: "t1" })
+      expect(sortChapters(a, b)).toBeGreaterThan(0)
+    })
+
+    it("should treat null order as 0", () => {
+      const a = makeChapter({ id: "1", title: "A", order: null, textbookId: "t1" })
+      const b = makeChapter({ id: "2", title: "B", order: 5, textbookId: "t1" })
+      expect(sortChapters(a, b)).toBeLessThan(0)
+    })
+  })
+
+  describe("buildChapterTree", () => {
+    it("should return empty array for empty input", () => {
+      expect(buildChapterTree([])).toEqual([])
+    })
+
+    it("should build single root", () => {
+      const rows: Chapter[] = [
+        makeChapter({ id: "1", title: "Root", order: 0, textbookId: "t1" }),
+      ]
+      const tree = buildChapterTree(rows)
+      expect(tree).toHaveLength(1)
+      expect(tree[0].id).toBe("1")
+      expect(tree[0].children).toEqual([])
+    })
+
+    it("should build nested tree", () => {
+      const rows: Chapter[] = [
+        makeChapter({ id: "1", title: "Root", order: 0, textbookId: "t1" }),
+        makeChapter({ id: "2", title: "Child 1", order: 0, textbookId: "t1", parentId: "1" }),
+        makeChapter({ id: "3", title: "Child 2", order: 1, textbookId: "t1", parentId: "1" }),
+        makeChapter({ id: "4", title: "Grandchild", order: 0, textbookId: "t1", parentId: "2" }),
+      ]
+      const tree = buildChapterTree(rows)
+      expect(tree).toHaveLength(1)
+      expect(tree[0].children).toHaveLength(2)
+      expect(tree[0].children[0].children).toHaveLength(1)
+      expect(tree[0].children[0].children[0].id).toBe("4")
+    })
+
+    it("should handle orphan nodes (parentId points to non-existent)", () => {
+      const rows: Chapter[] = [
+        makeChapter({ id: "1", title: "Orphan", order: 0, textbookId: "t1", parentId: "nonexistent" }),
+      ]
+      const tree = buildChapterTree(rows)
+      expect(tree).toHaveLength(1)
+      expect(tree[0].id).toBe("1")
+    })
+
+    it("should sort children by order", () => {
+      const rows: Chapter[] = [
+        makeChapter({ id: "1", title: "Root", order: 0, textbookId: "t1" }),
+        makeChapter({ id: "2", title: "B", order: 2, textbookId: "t1", parentId: "1" }),
+        makeChapter({ id: "3", title: "A", order: 1, textbookId: "t1", parentId: "1" }),
+      ]
+      const tree = buildChapterTree(rows)
+      expect(tree[0].children[0].id).toBe("3")
+      expect(tree[0].children[1].id).toBe("2")
+    })
+  })
+
+  describe("buildChapterIndex", () => {
+    it("should index all nodes including nested", () => {
+      const chapters: Chapter[] = [
+        makeChapter({
+          id: "1",
+          title: "Root",
+          order: 0,
+          textbookId: "t1",
+          children: [
+            makeChapter({ id: "2", title: "Child", order: 0, textbookId: "t1", parentId: "1", children: [] }),
+          ],
+        }),
+      ]
+      const index = buildChapterIndex(chapters)
+      expect(index.size).toBe(2)
+      expect(index.get("1")?.title).toBe("Root")
+      expect(index.get("2")?.title).toBe("Child")
+    })
+
+    it("should return empty map for empty input", () => {
+      expect(buildChapterIndex([]).size).toBe(0)
+    })
+  })
+
+  describe("findChapterParent", () => {
+    it("should find direct parent", () => {
+      const chapters: Chapter[] = [
+        makeChapter({
+          id: "1",
+          title: "Root",
+          order: 0,
+          textbookId: "t1",
+          children: [
+            makeChapter({ id: "2", title: "Child", order: 0, textbookId: "t1", parentId: "1", children: [] }),
+          ],
+        }),
+      ]
+      const parent = findChapterParent(chapters, "2")
+      expect(parent?.id).toBe("1")
+    })
+
+    it("should return null for root node", () => {
+      const chapters: Chapter[] = [
+        makeChapter({ id: "1", title: "Root", order: 0, textbookId: "t1", children: [] }),
+      ]
+      expect(findChapterParent(chapters, "1")).toBeNull()
+    })
+
+    it("should return null for non-existent id", () => {
+      expect(findChapterParent([], "nonexistent")).toBeNull()
+    })
+  })
+
+  describe("filterKnowledgePointsByChapter", () => {
+    it("should return empty for null chapterId", () => {
+      expect(filterKnowledgePointsByChapter([], null)).toEqual([])
+    })
+
+    it("should filter by chapterId", () => {
+      const kps: KnowledgePoint[] = [
+        { id: "1", name: "KP1", chapterId: "c1", level: 1, order: 0 },
+        { id: "2", name: "KP2", chapterId: "c2", level: 1, order: 0 },
+        { id: "3", name: "KP3", chapterId: "c1", level: 2, order: 0 },
+      ]
+      const result = filterKnowledgePointsByChapter(kps, "c1")
+      expect(result).toHaveLength(2)
+      expect(result[0].id).toBe("1")
+    })
+  })
+
+  describe("normalizeOptional", () => {
+    it("should return null for empty string", () => {
+      expect(normalizeOptional("")).toBeNull()
+    })
+
+    it("should return null for whitespace-only string", () => {
+      expect(normalizeOptional("   ")).toBeNull()
+    })
+
+    it("should return null for null/undefined", () => {
+      expect(normalizeOptional(null)).toBeNull()
+      expect(normalizeOptional(undefined)).toBeNull()
+    })
+
+    it("should trim and return non-empty string", () => {
+      expect(normalizeOptional("  hello  ")).toBe("hello")
+    })
+  })
+})
--- a/src/modules/textbooks/utils.ts
+++ b/src/modules/textbooks/utils.ts
@@ -0,0 +1,129 @@
+/**
+ * 教材模块纯逻辑工具函数。
+ *
+ * 从 data-access.ts 和组件中抽离的纯函数，便于单元测试。
+ */
+
+import type { Chapter, KnowledgePoint } from "./types"
+
+/**
+ * 章节排序比较器：先按 order 升序，order 相同按 title 字典序。
+ */
+export function sortChapters(a: Chapter, b: Chapter): number {
+  const ao = a.order ?? 0
+  const bo = b.order ?? 0
+  if (ao !== bo) return ao - bo
+  return a.title.localeCompare(b.title)
+}
+
+/**
+ * 将扁平章节列表构建为树形结构。
+ *
+ * 算法：
+ * 1. 第一遍遍历：所有章节放入 Map，并初始化 children: []
+ * 2. 第二遍遍历：根据 parentId 挂载到父节点的 children；无 parentId 或父节点不存在则作为根
+ * 3. 递归排序
+ *
+ * 时间复杂度 O(n log n)，空间复杂度 O(n)。
+ *
+ * @param rows 扁平章节列表（顺序无关）
+ * @returns 树形根节点数组（已排序），每个节点的 children 均已初始化为非空数组
+ */
+export function buildChapterTree(rows: Chapter[]): ChapterTreeNode[] {
+  type ChapterNode = ChapterTreeNode
+
+  const byId = new Map<string, ChapterNode>()
+  for (const ch of rows) {
+    byId.set(ch.id, { ...ch, children: [] })
+  }
+
+  const roots: ChapterNode[] = []
+  for (const ch of byId.values()) {
+    const pid = ch.parentId
+    if (pid) {
+      const parent = byId.get(pid)
+      if (parent) {
+        parent.children.push(ch)
+      } else {
+        roots.push(ch)
+      }
+    } else {
+      roots.push(ch)
+    }
+  }
+
+  const sortRecursive = (nodes: ChapterNode[]) => {
+    nodes.sort(sortChapters)
+    for (const n of nodes) {
+      sortRecursive(n.children)
+    }
+  }
+
+  sortRecursive(roots)
+  return roots
+}
+
+/**
+ * 章节树节点：在 Chapter 基础上强制 children 为非空数组。
+ */
+export type ChapterTreeNode = Chapter & { children: ChapterTreeNode[] }
+
+/**
+ * 构建章节索引 Map（id → Chapter），用于快速查找。
+ *
+ * 递归遍历整棵树，包括所有子节点。
+ */
+export function buildChapterIndex(chapters: Chapter[]): Map<string, Chapter> {
+  const index = new Map<string, Chapter>()
+
+  const walk = (nodes: Chapter[]) => {
+    for (const node of nodes) {
+      index.set(node.id, node)
+      if (node.children && node.children.length > 0) walk(node.children)
+    }
+  }
+
+  walk(chapters)
+  return index
+}
+
+/**
+ * 在章节树中查找某个章节的父节点。
+ *
+ * @returns 父节点；如果是根节点或未找到，返回 null。
+ */
+export function findChapterParent(
+  items: Chapter[],
+  id: string
+): Chapter | null {
+  for (const item of items) {
+    if (item.children?.some((c) => c.id === id)) return item
+    if (item.children) {
+      const found = findChapterParent(item.children, id)
+      if (found) return found
+    }
+  }
+  return null
+}
+
+/**
+ * 过滤出指定章节的知识点。
+ */
+export function filterKnowledgePointsByChapter(
+  knowledgePoints: KnowledgePoint[],
+  chapterId: string | null
+): KnowledgePoint[] {
+  if (!chapterId) return []
+  return knowledgePoints.filter((kp) => kp.chapterId === chapterId)
+}
+
+/**
+ * 规范化可选字符串字段：trim 后若为空返回 null。
+ */
+export function normalizeOptional(
+  v: string | null | undefined
+): string | null {
+  const trimmed = v?.trim()
+  if (!trimmed) return null
+  return trimmed
+}
--- a/src/modules/users/data-access.ts
+++ b/src/modules/users/data-access.ts
@@ -212,7 +212,7 @@ export const getUserWithRole = cache(
 * session and verifying the "student" role via JOIN users + usersToRoles + roles.
 * Returns null if not authenticated or the user does not have the student role.
 */
-export const getCurrentStudentUser = cache(async (): Promise<{ id: string; name: string } | null> => {
+export const getCurrentStudentUser = cache(async (): Promise<{ id: string; name: string; gradeId: string | null } | null> => {
  const session = await auth()
  const userId = String(session?.user?.id ?? "").trim()
  if (!userId) return null
@@ -220,7 +220,15 @@ export const getCurrentStudentUser = cache(async (): Promise<{ id: string; name:
  const student = await getUserWithRole(userId, "student")

  if (!student) return null
-  return { id: student.id, name: student.name || "Student" }
+
+  // 查询学生的 gradeId（关联 grades 表）
+  const [userRow] = await db
+    .select({ gradeId: users.gradeId })
+    .from(users)
+    .where(eq(users.id, student.id))
+    .limit(1)
+
+  return { id: student.id, name: student.name || "Student", gradeId: userRow?.gradeId ?? null }
 })

 /** Returns a map of userId -> { name, email } for the given user ids. */