diff --git a/CLAUDE.md b/CLAUDE.md
index 9919bfb..afbf642 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -5,7 +5,7 @@
 
 ## Current Status
 
-**Phase 1b in progress.** Category CRUD + Question CRUD done. Remaining: 知识卡编辑、题目状态流转 UI 完善、批量导入。
+**Phase 1b in progress.** Category CRUD + Question CRUD + 知识卡编辑 done. Remaining: 题目状态流转 UI 完善、批量导入。
 
 Development follows the phased roadmap in [dev-spec.md](./dev-spec.md) §九.
 
@@ -38,7 +38,7 @@ src/
 │   ├── layout/           # Sidebar, Header, AdminLayout
 │   ├── charts/           # StatsCard, chart wrappers
 │   ├── category/         # Category CRUD (columns, dialogs)
-│   ├── question/         # Question CRUD (columns, form, StatusBadge, DistractorEditor)
+│   ├── question/         # Question CRUD (columns, form, StatusBadge, DistractorEditor, KnowledgeCardFields)
 ├── lib/
 │   ├── api-client.ts     # HTTP client for /admin/* endpoints
 │   ├── auth.ts           # Admin JWT token management
diff --git a/src/components/question/KnowledgeCardFields.tsx b/src/components/question/KnowledgeCardFields.tsx
new file mode 100644
index 0000000..6551ae7
--- /dev/null
+++ b/src/components/question/KnowledgeCardFields.tsx
@@ -0,0 +1,178 @@
+import { useState } from "react"
+import type { UseFormRegisterReturn } from "react-hook-form"
+import { Button } from "@/components/ui/button"
+import { Input } from "@/components/ui/input"
+import { Label } from "@/components/ui/label"
+import { Textarea } from "@/components/ui/textarea"
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from "@/components/ui/card"
+import { Badge } from "@/components/ui/badge"
+
+const BASIC_MAX = 100
+const DEEP_MAX = 300
+
+interface KnowledgeCardFieldsProps {
+  basicRegister: UseFormRegisterReturn
+  deepRegister: UseFormRegisterReturn
+  sourceRefRegister: UseFormRegisterReturn
+  basicError?: string
+  deepError?: string
+  watchBasic: string
+  watchDeep: string
+}
+
+export function KnowledgeCardFields({
+  basicRegister,
+  deepRegister,
+  sourceRefRegister,
+  basicError,
+  deepError,
+  watchBasic,
+  watchDeep,
+}: KnowledgeCardFieldsProps) {
+  const [showPreview, setShowPreview] = useState(false)
+  const [deepExpanded, setDeepExpanded] = useState(!!watchDeep)
+
+  const basicCount = watchBasic.length
+  const deepCount = watchDeep.length
+  const basicOver = basicCount > BASIC_MAX
+  const deepOver = deepCount > DEEP_MAX
+
+  return (
+    <div className="space-y-4">
+      {/* 基础版 */}
+      <div className="space-y-2">
+        <div className="flex items-center gap-2">
+          <Label htmlFor="knowledgeCardBasic">知识卡（基础版）</Label>
+          <Badge variant="secondary" className="text-xs">
+            所有用户可见
+          </Badge>
+        </div>
+        <p className="text-sm text-muted-foreground">
+          2-3 句趣味解读，让用户答完题后学到新知识
+        </p>
+        <Textarea
+          id="knowledgeCardBasic"
+          placeholder="例：唐太宗李世民不仅是千古一帝，还是书法发烧友。他最爱王羲之的字，据说《兰亭集序》真迹被他带进了昭陵。"
+          rows={3}
+          {...basicRegister}
+        />
+        <div className="flex items-center justify-between">
+          {basicError && (
+            <p className="text-sm text-destructive">{basicError}</p>
+          )}
+          <span
+            className={`ml-auto text-xs ${basicOver ? "text-destructive font-medium" : "text-muted-foreground"}`}
+          >
+            {basicCount}/{BASIC_MAX}
+          </span>
+        </div>
+      </div>
+
+      {/* 深度版 */}
+      <div className="space-y-2">
+        <button
+          type="button"
+          className="flex items-center gap-2"
+          onClick={() => setDeepExpanded((prev) => !prev)}
+        >
+          <Label className="cursor-pointer">知识卡（深度版）</Label>
+          <Badge variant="outline" className="text-xs">
+            Pro 用户可见
+          </Badge>
+          <span className="text-xs text-muted-foreground">
+            {deepExpanded ? "收起" : "展开"}
+          </span>
+        </button>
+
+        {deepExpanded && (
+          <>
+            <p className="text-sm text-muted-foreground">
+              扩展背景故事、趣味延伸，给 Pro 用户更深层的内容体验
+            </p>
+            <Textarea
+              placeholder="例：王羲之写《兰亭集序》时喝了点酒，一气呵成。后来他多次重写都不满意，感叹「此神助耳，何吾能力致」。唐太宗派萧翼用计从辩才和尚手中骗得真迹，临终遗命将真迹陪葬昭陵。不过近年有学者认为，真迹可能并未入昭陵，而是另有下落……"
+              rows={5}
+              {...deepRegister}
+            />
+            <div className="flex items-center justify-between">
+              {deepError && (
+                <p className="text-sm text-destructive">{deepError}</p>
+              )}
+              <span
+                className={`ml-auto text-xs ${deepOver ? "text-destructive font-medium" : "text-muted-foreground"}`}
+              >
+                {deepCount}/{DEEP_MAX}
+              </span>
+            </div>
+          </>
+        )}
+      </div>
+
+      {/* 来源参考 */}
+      <div className="space-y-2">
+        <Label htmlFor="sourceRef">
+          来源参考
+          <span className="ml-1 text-muted-foreground font-normal">选填</span>
+        </Label>
+        <Input
+          id="sourceRef"
+          placeholder="如：《旧唐书·太宗本纪》"
+          {...sourceRefRegister}
+        />
+      </div>
+
+      {/* 预览切换 */}
+      <Button
+        type="button"
+        variant="outline"
+        size="sm"
+        onClick={() => setShowPreview((prev) => !prev)}
+      >
+        {showPreview ? "关闭预览" : "预览效果"}
+      </Button>
+
+      {showPreview && (
+        <Card className="border-dashed">
+          <CardHeader>
+            <CardTitle className="text-base">知识卡预览</CardTitle>
+            <CardDescription>
+              用户答完题后看到的知识卡效果
+            </CardDescription>
+          </CardHeader>
+          <CardContent className="space-y-3">
+            {watchBasic ? (
+              <p className="text-sm leading-relaxed">{watchBasic}</p>
+            ) : (
+              <p className="text-sm text-muted-foreground italic">
+                （基础版内容为空）
+              </p>
+            )}
+            {watchDeep && (
+              <>
+                <div className="border-t pt-3">
+                  <div className="flex items-center gap-1 mb-1">
+                    <Badge variant="outline" className="text-xs">
+                      Pro
+                    </Badge>
+                    <span className="text-xs text-muted-foreground">
+                      深度解读
+                    </span>
+                  </div>
+                  <p className="text-sm leading-relaxed text-muted-foreground">
+                    {watchDeep}
+                  </p>
+                </div>
+              </>
+            )}
+          </CardContent>
+        </Card>
+      )}
+    </div>
+  )
+}
diff --git a/src/components/question/QuestionForm.tsx b/src/components/question/QuestionForm.tsx
index ced8e81..b7e0f4c 100644
--- a/src/components/question/QuestionForm.tsx
+++ b/src/components/question/QuestionForm.tsx
@@ -16,6 +16,7 @@ import {
   SelectValue,
 } from "@/components/ui/select"
 import { DistractorEditor } from "@/components/question/DistractorEditor"
+import { KnowledgeCardFields } from "@/components/question/KnowledgeCardFields"
 import { fetchCategories } from "@/lib/api/category-api"
 import { DIFFICULTY_LABELS, QUESTION_STATUSES } from "@/lib/constants"
 import type { Question, Difficulty, QuestionStatus } from "@/types/question"
@@ -33,6 +34,7 @@ const questionSchema = z.object({
   status: z.enum(["draft", "reviewing", "published", "archived"]),
   knowledgeCardBasic: z.string().min(1, "请填写基础知识卡").max(100),
   knowledgeCardDeep: z.string().max(300).optional(),
+  sourceRef: z.string().max(500).optional(),
 })
 
 type FormValues = z.infer<typeof questionSchema>
@@ -65,6 +67,7 @@ export function QuestionForm({ question }: QuestionFormProps) {
           status: question.status,
           knowledgeCardBasic: question.knowledgeCardBasic,
           knowledgeCardDeep: question.knowledgeCardDeep ?? "",
+          sourceRef: question.sourceRef ?? "",
         }
       : {
           stem: "",
@@ -75,6 +78,7 @@ export function QuestionForm({ question }: QuestionFormProps) {
           status: "draft",
           knowledgeCardBasic: "",
           knowledgeCardDeep: "",
+          sourceRef: "",
         },
   })
 
@@ -208,40 +212,16 @@ export function QuestionForm({ question }: QuestionFormProps) {
 
       <Separator />
 
-      {/* 知识卡（基础版） */}
-      <div className="space-y-2">
-        <Label htmlFor="knowledgeCardBasic">知识卡（基础版）</Label>
-        <Textarea
-          id="knowledgeCardBasic"
-          placeholder="2-3 句趣味解读，100 字以内"
-          rows={3}
-          {...register("knowledgeCardBasic")}
-        />
-        {errors.knowledgeCardBasic && (
-          <p className="text-sm text-destructive">
-            {errors.knowledgeCardBasic.message}
-          </p>
-        )}
-      </div>
-
-      {/* 知识卡（深度版） */}
-      <div className="space-y-2">
-        <Label htmlFor="knowledgeCardDeep">
-          知识卡（深度版）
-          <span className="ml-1 text-muted-foreground font-normal">选填</span>
-        </Label>
-        <Textarea
-          id="knowledgeCardDeep"
-          placeholder="扩展背景故事、趣味延伸，300 字以内"
-          rows={4}
-          {...register("knowledgeCardDeep")}
-        />
-        {errors.knowledgeCardDeep && (
-          <p className="text-sm text-destructive">
-            {errors.knowledgeCardDeep.message}
-          </p>
-        )}
-      </div>
+      {/* 知识卡 */}
+      <KnowledgeCardFields
+        basicRegister={register("knowledgeCardBasic")}
+        deepRegister={register("knowledgeCardDeep")}
+        sourceRefRegister={register("sourceRef")}
+        basicError={errors.knowledgeCardBasic?.message}
+        deepError={errors.knowledgeCardDeep?.message}
+        watchBasic={watch("knowledgeCardBasic") ?? ""}
+        watchDeep={watch("knowledgeCardDeep") ?? ""}
+      />
 
       {/* 提交 */}
       <div className="flex justify-end gap-2 pt-2">
diff --git a/src/types/question.ts b/src/types/question.ts
index 9c243ca..263928b 100644
--- a/src/types/question.ts
+++ b/src/types/question.ts
@@ -11,6 +11,7 @@ export interface Question {
   status: QuestionStatus
   knowledgeCardBasic: string
   knowledgeCardDeep?: string
+  sourceRef?: string
   source: "system" | "ugc"
   stats: {
     timesAnswered: number
@@ -30,4 +31,5 @@ export interface QuestionFormData {
   status: QuestionStatus
   knowledgeCardBasic: string
   knowledgeCardDeep?: string
+  sourceRef?: string
 }