diff --git a/apps/web/src/admin/api.ts b/apps/web/src/admin/api.ts
index db949aa..99cd557 100644
--- a/apps/web/src/admin/api.ts
+++ b/apps/web/src/admin/api.ts
@@ -1,7 +1,6 @@
 import api from "utils/api"
 import { toAdminProblemRow } from "admin/transforms"
 import type {
-  AcTrend,
   BatchProblemTagResponse,
   GenerateSqlTestCaseResponse,
   RenameTagResponse,
@@ -9,6 +8,8 @@ import type {
   AdminAiReport,
   AdminAiReportList,
   StuckProblem,
+  StuckProblemDetail,
+  YearlyOverview,
   LearnBoard,
   LearnExerciseProgressList,
   LearnExerciseAttempt,
@@ -598,9 +599,13 @@ export function deleteProblemSetBadge(problemSetId: number, badgeId: number) {
   return api.delete(`admin/problem-sets/${problemSetId}/badges/${badgeId}`)
 }
 
-// 学生卡点分析
-export function getStuckProblems() {
-  return api.get<StuckProblem[]>("admin/problem-analytics/stuck")
+// 卡点分析：start 是时间段的起点（ISO），不给就是全部时间
+export function getStuckProblems(params: { className?: string; start?: string }) {
+  return api.get<StuckProblem[]>("admin/problem-analytics/stuck", { params })
+}
+
+export function getStuckProblemDetail(id: number, params: { className?: string; start?: string }) {
+  return api.get<StuckProblemDetail>(`admin/problem-analytics/stuck/${id}`, { params })
 }
 
 export function getLearnBoard(params: { type: "python" | "c"; className?: string }) {
@@ -619,12 +624,8 @@ export function getLearnExerciseAttempts(exerciseId: number, params: { className
   })
 }
 
-export function getTopACTrend(params: {
-  sinceYear: number
-  untilYear: number
-  minPerYear: number
-}) {
-  return api.get<AcTrend[]>("admin/problem-analytics/ac-trend", { params })
+export function getYearlyOverview() {
+  return api.get<YearlyOverview>("admin/problem-analytics/yearly")
 }
 
 // AI 学习分析报告
diff --git a/apps/web/src/admin/problem/Stuck.vue b/apps/web/src/admin/problem/Stuck.vue
index f69da70..3818367 100644
--- a/apps/web/src/admin/problem/Stuck.vue
+++ b/apps/web/src/admin/problem/Stuck.vue
@@ -1,49 +1,863 @@
 <script setup lang="ts">
-import PageHeader from "admin/components/PageHeader.vue"
-import { getStuckProblems } from "admin/api"
-import type { StuckProblem } from "utils/types"
+import { useRouteQuery } from "@vueuse/router"
+import { zonedParts } from "utils/functions"
+import type { StuckProblem, StuckProblemDetail, StuckStudent } from "utils/types"
+import { getStuckProblemDetail, getStuckProblems } from "admin/api"
+import { useConfigStore } from "shared/store/config"
+import UserName from "shared/components/UserName.vue"
+import { classLabel, groupClassOptions } from "oj/submission/utils"
+import { periodRange, type Period } from "oj/statistics/period"
+import { resultName, useResultColor } from "oj/statistics/results"
+import "oj/learn/learn.css"
 
-const loading = ref(true)
-const data = ref<StuckProblem[]>([])
+/**
+ * 卡点分析（设计稿「卡点与趋势」页的定稿 StuckFinalAll / StuckFinalClass）：
+ * 知识点 → 这个知识点下的题 → 一道题。
+ *
+ * 口径见后端 routes/admin/analytics.ts：人 × 题，「一次就对」= 第一次交就对的人占比，
+ * 「平均交几次」只数做对那次及之前的。门槛（至少几人做过）在前端卡，知识点的汇总跟着门槛走 ——
+ * 选了一个班时默认 10 人，相当于「课上布置过的」，不然会混进一两个人自己做的题。
+ */
+const router = useRouter()
+const configStore = useConfigStore()
+const resultColor = useResultColor()
 
-const columns: DataTableColumn<StuckProblem>[] = [
-  { title: "题目 ID", key: "problemId", width: 100 },
-  { title: "题目名称", key: "problemTitle", minWidth: 200 },
-  { title: "总提交", key: "total", width: 100, sorter: "default" },
-  { title: "失败次数", key: "failed", width: 100, sorter: "default" },
-  {
-    title: "卡住学生数",
-    key: "failedUsers",
-    width: 120,
-    sorter: "default",
-    defaultSortOrder: "descend",
-  },
-  {
-    title: "AC 率",
-    key: "acRate",
-    width: 100,
-    sorter: "default",
-    render: (row) => `${row.acRate}%`,
-  },
+const PERIODS: { label: string; value: Period }[] = [
+  { label: "这学期", value: "term" },
+  { label: "最近 30 天", value: "30d" },
+  { label: "最近 7 天", value: "7d" },
+  { label: "全部", value: "all" },
 ]
+const THRESHOLDS = [5, 10, 20, 50]
 
-onMounted(async () => {
+const className = useRouteQuery<string>("className", "", { mode: "replace" })
+const period = useRouteQuery<string>("period", "term", { mode: "replace" })
+const tag = useRouteQuery<string>("tag", "", { mode: "replace" })
+const picked = useRouteQuery<string>("problem", "", { mode: "replace" })
+const min = useRouteQuery<string>("min", "", { mode: "replace" })
+
+const problems = ref<StuckProblem[]>([])
+const detail = ref<StuckProblemDetail | null>(null)
+const loading = ref(false)
+const detailLoading = ref(false)
+
+const classOptions = computed(() => groupClassOptions(configStore.config?.classList ?? []))
+const threshold = computed(() => Number(min.value) || (className.value ? 10 : 20))
+const thresholdOptions = computed(() =>
+  THRESHOLDS.map((n) => ({ label: `至少 ${n} 人做过`, value: n })),
+)
+
+function rate(part: number, whole: number) {
+  return whole ? Math.round((part / whole) * 100) : 0
+}
+
+function firstRate(row: StuckProblem) {
+  return rate(row.firstTry, row.users)
+}
+
+function avgTries(row: { solved: number; solvedTries: number }) {
+  return row.solved ? (row.solvedTries / row.solved).toFixed(1) : "-"
+}
+
+function range() {
+  return periodRange(period.value as Period, null).start
+}
+
+const visible = computed(() => problems.value.filter((row) => row.users >= threshold.value))
+
+/** 知识点：按门槛过滤后的题，人数加权；「全部」在最前，其余一次就对从低到高 */
+const knowledge = computed(() => {
+  const groups = new Map<string, { problems: number; users: number; firstTry: number }>()
+  for (const row of visible.value) {
+    for (const name of row.tags) {
+      const group = groups.get(name) ?? { problems: 0, users: 0, firstTry: 0 }
+      group.problems += 1
+      group.users += row.users
+      group.firstTry += row.firstTry
+      groups.set(name, group)
+    }
+  }
+  const all = visible.value.reduce(
+    (sum, row) => ({ users: sum.users + row.users, firstTry: sum.firstTry + row.firstTry }),
+    { users: 0, firstTry: 0 },
+  )
+  return [
+    {
+      name: "",
+      label: "全部",
+      problems: visible.value.length,
+      rate: rate(all.firstTry, all.users),
+    },
+    ...[...groups]
+      .map(([name, group]) => ({
+        name,
+        label: name,
+        problems: group.problems,
+        rate: rate(group.firstTry, group.users),
+      }))
+      .sort((a, b) => a.rate - b.rate || b.problems - a.problems),
+  ]
+})
+
+const activeTag = computed(() =>
+  knowledge.value.some((row) => row.name === tag.value) ? tag.value : "",
+)
+
+const list = computed(() =>
+  visible.value
+    .filter((row) => !activeTag.value || row.tags.includes(activeTag.value))
+    .sort((a, b) => firstRate(a) - firstRate(b) || b.users - a.users),
+)
+
+const selected = computed(
+  () => list.value.find((row) => String(row.id) === picked.value) ?? list.value[0] ?? null,
+)
+
+async function load() {
+  loading.value = true
   try {
-    const res = await getStuckProblems()
-    data.value = res
+    problems.value = await getStuckProblems({
+      className: className.value || undefined,
+      start: range(),
+    })
   } finally {
     loading.value = false
   }
+}
+
+let detailToken = 0
+async function loadDetail() {
+  const row = selected.value
+  const token = ++detailToken
+  if (!row) {
+    detail.value = null
+    return
+  }
+  detailLoading.value = true
+  try {
+    const data = await getStuckProblemDetail(row.id, {
+      className: className.value || undefined,
+      start: range(),
+    })
+    if (token === detailToken) detail.value = data
+  } finally {
+    if (token === detailToken) detailLoading.value = false
+  }
+}
+
+watch([className, period], load)
+watch(() => [selected.value?.id, problems.value] as const, loadDetail)
+onMounted(load)
+
+// ---------------------------------------------------------------- 一道题
+
+const students = computed(() => detail.value?.students ?? [])
+const summary = computed(() => {
+  const rows = students.value
+  const solved = rows.filter((row) => row.solved)
+  return {
+    users: rows.length,
+    firstRate: rate(rows.filter((row) => row.firstTry).length, rows.length),
+    avgTries: avgTries({
+      solved: solved.length,
+      solvedTries: solved.reduce((sum, row) => sum + row.tries, 0),
+    }),
+    stuck: rows.length - solved.length,
+  }
+})
+
+const errorTotal = computed(() =>
+  (detail.value?.errors ?? []).reduce((sum, row) => sum + row.count, 0),
+)
+
+const byClass = computed(() => {
+  const groups = new Map<string, StuckStudent[]>()
+  for (const row of students.value) {
+    const key = row.className ?? ""
+    groups.set(key, [...(groups.get(key) ?? []), row])
+  }
+  return [...groups]
+    .map(([name, rows]) => {
+      const solved = rows.filter((row) => row.solved)
+      return {
+        name,
+        users: rows.length,
+        rate: rate(rows.filter((row) => row.firstTry).length, rows.length),
+        avgTries: avgTries({
+          solved: solved.length,
+          solvedTries: solved.reduce((sum, row) => sum + row.tries, 0),
+        }),
+        stuck: rows.length - solved.length,
+      }
+    })
+    .sort((a, b) => b.users - a.users)
+})
+
+const BUCKETS = [
+  { label: "1 次", min: 1, max: 1 },
+  { label: "2 次", min: 2, max: 2 },
+  { label: "3 次", min: 3, max: 3 },
+  { label: "4–5 次", min: 4, max: 5 },
+  { label: "6 次以上", min: 6, max: Infinity },
+]
+const distribution = computed(() => {
+  const solved = students.value.filter((row) => row.solved)
+  const rows = BUCKETS.map((bucket) => ({
+    ...bucket,
+    count: solved.filter((row) => row.tries >= bucket.min && row.tries <= bucket.max).length,
+  }))
+  const max = Math.max(1, ...rows.map((row) => row.count))
+  return rows.map((row) => ({ ...row, height: Math.max(2, (row.count / max) * 64) }))
+})
+
+const mostTries = computed(() =>
+  students.value
+    .filter((row) => row.solved && row.tries >= 3)
+    .sort((a, b) => b.tries - a.tries)
+    .slice(0, 6),
+)
+
+const stuckStudents = computed(() =>
+  students.value.filter((row) => !row.solved).sort((a, b) => b.tries - a.tries),
+)
+
+const currentYear = (() => {
+  const now = zonedParts(new Date())!
+  return now.month >= 9 ? now.year : now.year - 1
+})()
+const history = computed(() =>
+  (detail.value?.history ?? []).map((row) => ({
+    label: `${String(row.year).slice(2)}–${String(row.year + 1).slice(2)}`,
+    current: row.year === currentYear,
+    users: row.users,
+    rate: rate(row.firstTry, row.users),
+  })),
+)
+
+function gap(minutes: number | null) {
+  if (minutes === null) return ""
+  if (minutes < 1) return "不到 1 分钟"
+  if (minutes < 60) return `${minutes} 分钟`
+  if (minutes < 1440) return `${Math.round(minutes / 60)} 小时`
+  return `隔了 ${Math.round(minutes / 1440)} 天`
+}
+
+function href(to: Parameters<typeof router.resolve>[0]) {
+  return router.resolve(to).href
+}
+
+const links = computed(() => {
+  const row = detail.value?.problem
+  if (!row) return null
+  const scope = className.value ? { className: className.value } : {}
+  return {
+    problem: href({ name: "problem", params: { problemID: row.displayId } }),
+    statistics: href({
+      name: "statistics",
+      query: { problem: row.displayId, period: period.value, ...scope },
+    }),
+    submissions: href({ name: "submissions", query: { problem: row.displayId, ...scope } }),
+  }
 })
 </script>
 
 <template>
-  <PageHeader title="卡点分析" description="只分析前 40 道题目" />
-  <n-data-table
-    :loading="loading"
-    :columns="columns"
-    :data="data"
-    striped
-    :pagination="{ pageSize: 20 }"
-  />
+  <div class="page">
+    <div class="top">
+      <span class="title">卡点分析</span>
+      <span class="grow" />
+      <n-select
+        :value="className || null"
+        :options="classOptions"
+        filterable
+        clearable
+        placeholder="全部班级"
+        style="width: 170px"
+        @update:value="(value: string | null) => (className = value ?? '')"
+      />
+      <div class="seg">
+        <button
+          v-for="option in PERIODS"
+          :key="option.value"
+          type="button"
+          :class="{ on: period === option.value }"
+          @click="period = option.value"
+        >
+          {{ option.label }}
+        </button>
+      </div>
+    </div>
+
+    <n-spin :show="loading">
+      <div class="main">
+        <section class="card know">
+          <div class="card-head">
+            <span class="strong">知识点</span>
+            <span class="grow" />
+            <span class="muted small">一次就对</span>
+          </div>
+          <button
+            v-for="row in knowledge"
+            :key="row.name"
+            type="button"
+            class="item"
+            :class="{ on: row.name === activeTag }"
+            @click="tag = row.name"
+          >
+            <span class="line">
+              <span class="name">{{ row.label }}</span>
+              <span class="grow" />
+              <span class="muted small num">{{ row.problems }} 道</span>
+            </span>
+            <span class="line">
+              <span class="track"><span :style="{ width: `${row.rate}%` }" /></span>
+              <span class="pct num">{{ row.rate }}%</span>
+            </span>
+          </button>
+        </section>
+
+        <section class="card problems">
+          <div class="card-head">
+            <span class="strong">{{ activeTag || "全部" }}</span>
+            <span class="muted small num">{{ list.length }} 道</span>
+            <span class="grow" />
+            <n-select
+              :value="threshold"
+              :options="thresholdOptions"
+              size="small"
+              style="width: 130px"
+              @update:value="(value: number) => (min = String(value))"
+            />
+          </div>
+          <div class="scroll">
+            <div v-if="!list.length && !loading" class="none muted">
+              这段时间还没有 {{ threshold }} 人以上做过的题
+            </div>
+            <button
+              v-for="row in list"
+              :key="row.id"
+              type="button"
+              class="item"
+              :class="{ on: row.id === selected?.id }"
+              @click="picked = String(row.id)"
+            >
+              <span class="line">
+                <span class="pid muted num">{{ row.displayId }}</span>
+                <span class="ptitle">{{ row.title }}</span>
+                <span v-if="row.users > row.solved" class="stuck num">
+                  {{ row.users - row.solved }} 人没对
+                </span>
+              </span>
+              <span class="line indent">
+                <span class="track short"><span :style="{ width: `${firstRate(row)}%` }" /></span>
+                <span class="pct num">{{ firstRate(row) }}%</span>
+                <span class="muted small num nowrap">
+                  {{ row.users }} 人 · 平均 {{ avgTries(row) }} 次
+                </span>
+              </span>
+            </button>
+          </div>
+        </section>
+
+        <section v-if="list.length" class="card detail">
+          <n-spin :show="detailLoading">
+            <div v-if="detail && links" class="detail-body">
+              <div class="line dhead">
+                <span class="muted num">{{ detail.problem.displayId }}</span>
+                <span class="dtitle">{{ detail.problem.title }}</span>
+                <span v-for="name in detail.problem.tags" :key="name" class="tag">{{ name }}</span>
+                <span class="links">
+                  <a :href="links.problem" target="_blank" class="link">去题目 ›</a>
+                  <a :href="links.statistics" target="_blank" class="link">数据统计 ›</a>
+                </span>
+              </div>
+
+              <div class="stats">
+                <div>
+                  <div class="muted small">做过</div>
+                  <div class="big num">{{ summary.users }}<span class="unit"> 人</span></div>
+                </div>
+                <div>
+                  <div class="muted small">一次就对</div>
+                  <div class="big num">{{ summary.firstRate }}%</div>
+                </div>
+                <div>
+                  <div class="muted small">做对平均交</div>
+                  <div class="big num">{{ summary.avgTries }}<span class="unit"> 次</span></div>
+                </div>
+                <div>
+                  <div class="muted small">还没做对</div>
+                  <div class="big num" :class="{ red: summary.stuck }">
+                    {{ summary.stuck }}<span class="unit"> 人</span>
+                  </div>
+                </div>
+              </div>
+
+              <div v-if="errorTotal" class="block">
+                <div class="muted small">错在哪 · {{ errorTotal }} 次</div>
+                <div class="errbar">
+                  <span
+                    v-for="row in detail.errors"
+                    :key="row.result"
+                    :style="{
+                      width: `${(row.count / errorTotal) * 100}%`,
+                      background: resultColor(row.result),
+                    }"
+                  />
+                </div>
+                <div class="line small num errtext">
+                  <span v-for="row in detail.errors" :key="row.result" class="legend">
+                    <i :style="{ background: resultColor(row.result) }" />{{
+                      resultName(row.result)
+                    }}
+                    {{ row.count }}
+                  </span>
+                </div>
+              </div>
+
+              <div v-if="!className" class="block">
+                <div class="muted small">各班</div>
+                <div v-for="row in byClass" :key="row.name" class="crow">
+                  <span class="cname">{{ classLabel(row.name || null) }}</span>
+                  <span class="num cusers">{{ row.users }} 人</span>
+                  <span class="track mid"><span :style="{ width: `${row.rate}%` }" /></span>
+                  <span class="pct num">{{ row.rate }}%</span>
+                  <span class="muted num cavg">平均 {{ row.avgTries }} 次</span>
+                  <span class="grow" />
+                  <span v-if="row.stuck" class="stuck num">{{ row.stuck }} 人没对</span>
+                  <span v-else class="muted">都对了</span>
+                </div>
+              </div>
+
+              <template v-else>
+                <div class="block">
+                  <div class="muted small">交了几次才对</div>
+                  <div class="dist">
+                    <div v-for="row in distribution" :key="row.label" class="dcol">
+                      <span class="small num strong">{{ row.count }} 人</span>
+                      <span
+                        class="dbar"
+                        :class="{ first: row.min === 1, many: row.min === 6 }"
+                        :style="{ height: `${row.height}px` }"
+                      />
+                      <span class="muted small">{{ row.label }}</span>
+                    </div>
+                  </div>
+                </div>
+                <div v-if="mostTries.length" class="block">
+                  <div class="muted small">交得最多的</div>
+                  <div class="names">
+                    <div v-for="row in mostTries" :key="row.username" class="nrow">
+                      <UserName :username="row.username" class="uname" />
+                      <span class="num strong ntries">交了 {{ row.tries }} 次</span>
+                      <span class="muted num">{{ gap(row.minutes) }}</span>
+                      <span class="grow" />
+                      <a
+                        :href="
+                          href({
+                            name: 'submissions',
+                            query: { problem: detail.problem.displayId, username: row.username },
+                          })
+                        "
+                        target="_blank"
+                        class="link small"
+                        >看代码</a
+                      >
+                    </div>
+                  </div>
+                </div>
+              </template>
+
+              <div v-if="history.length" class="block">
+                <div class="muted small">历年一次就对{{ className ? "（全站）" : "" }}</div>
+                <div v-for="row in history" :key="row.label" class="hrow num">
+                  <span class="hlabel" :class="{ muted: !row.current }">
+                    {{ row.label }}{{ row.current ? " 这学年" : "" }}
+                  </span>
+                  <span class="track mid" :class="{ past: !row.current }"
+                    ><span :style="{ width: `${row.rate}%` }"
+                  /></span>
+                  <span class="pct" :class="{ strong: row.current }">{{ row.rate }}%</span>
+                  <span class="muted small">{{ row.users }} 人</span>
+                </div>
+              </div>
+
+              <div v-if="stuckStudents.length" class="block">
+                <div class="line">
+                  <span class="muted small">还没做对的 {{ stuckStudents.length }} 人</span>
+                  <span class="grow" />
+                  <a :href="links.submissions" target="_blank" class="link small"
+                    >在提交列表里看 ›</a
+                  >
+                </div>
+                <div class="names">
+                  <div v-for="row in stuckStudents" :key="row.username" class="nrow">
+                    <UserName :username="row.username" class="uname" />
+                    <span class="muted num ntries">交了 {{ row.tries }} 次</span>
+                    <span class="legend" :style="{ color: resultColor(row.lastResult) }">
+                      <i :style="{ background: resultColor(row.lastResult) }" />{{
+                        resultName(row.lastResult)
+                      }}
+                    </span>
+                    <span class="grow" />
+                    <a
+                      :href="href({ path: `/submission/${row.lastSubmissionId}` })"
+                      target="_blank"
+                      class="link small"
+                      >看代码</a
+                    >
+                  </div>
+                </div>
+              </div>
+            </div>
+          </n-spin>
+        </section>
+      </div>
+    </n-spin>
+  </div>
 </template>
+
+<style scoped>
+.page {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+.top {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+}
+.title {
+  font-size: 20px;
+  font-weight: 700;
+}
+.grow {
+  flex: 1;
+}
+.muted {
+  opacity: 0.6;
+}
+.small {
+  font-size: 12px;
+}
+.strong {
+  font-weight: 700;
+}
+.num {
+  font-variant-numeric: tabular-nums;
+}
+.seg {
+  display: flex;
+}
+.seg button {
+  height: 32px;
+  padding: 0 12px;
+  border: 1px solid rgba(128, 128, 128, 0.3);
+  background: transparent;
+  color: inherit;
+  font: inherit;
+  font-size: 13px;
+  cursor: pointer;
+  margin-left: -1px;
+}
+.seg button:first-child {
+  border-radius: 4px 0 0 4px;
+  margin-left: 0;
+}
+.seg button:last-child {
+  border-radius: 0 4px 4px 0;
+}
+.seg button.on {
+  border-color: var(--learn-green);
+  color: var(--learn-green-text);
+  font-weight: 600;
+  position: relative;
+}
+.main {
+  display: flex;
+  gap: 12px;
+  align-items: flex-start;
+}
+.card {
+  border: 1px solid var(--learn-line);
+  border-radius: 8px;
+  overflow: hidden;
+}
+.card-head {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  height: 44px;
+  padding: 0 16px;
+  font-size: 15px;
+}
+.know {
+  width: 220px;
+  flex-shrink: 0;
+}
+.problems {
+  width: 340px;
+  flex-shrink: 0;
+}
+.scroll {
+  max-height: calc(100vh - 210px);
+  overflow-y: auto;
+}
+.detail {
+  flex: 1;
+  min-width: 0;
+  min-height: 200px;
+}
+.item {
+  display: flex;
+  flex-direction: column;
+  gap: 5px;
+  width: 100%;
+  padding: 9px 16px;
+  border: 0;
+  border-top: 1px solid var(--learn-line);
+  background: transparent;
+  color: inherit;
+  font: inherit;
+  text-align: left;
+  cursor: pointer;
+}
+.item:hover {
+  background: var(--learn-soft);
+}
+.item.on {
+  background: var(--learn-green-bg);
+  box-shadow: inset 3px 0 0 var(--learn-green);
+}
+.item.on .name,
+.item.on .ptitle {
+  font-weight: 600;
+}
+.line {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+}
+.indent {
+  padding-left: 42px;
+  gap: 8px;
+}
+.nowrap {
+  white-space: nowrap;
+}
+.links {
+  display: flex;
+  gap: 12px;
+  margin-left: auto;
+}
+.pid {
+  width: 34px;
+  flex-shrink: 0;
+}
+.ptitle {
+  flex: 1;
+  min-width: 0;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+.stuck {
+  flex-shrink: 0;
+  font-size: 13px;
+  font-weight: 600;
+  color: var(--learn-red-text);
+}
+.track {
+  display: block;
+  flex-shrink: 0;
+  width: 170px;
+  height: 8px;
+  border-radius: 4px;
+  background: var(--learn-todo);
+  overflow: hidden;
+}
+.track > span {
+  display: block;
+  height: 100%;
+  background: var(--learn-green);
+}
+.know .track {
+  width: 130px;
+}
+.track.short {
+  width: 90px;
+}
+.track.mid {
+  width: 90px;
+}
+.track.past > span {
+  background: var(--learn-green-line);
+}
+.pct {
+  width: 38px;
+  flex-shrink: 0;
+  text-align: right;
+  font-weight: 600;
+}
+.none {
+  padding: 24px 16px;
+  font-size: 13px;
+}
+.detail-body {
+  padding: 14px 18px;
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+.dhead {
+  flex-wrap: wrap;
+  row-gap: 4px;
+}
+.dtitle {
+  font-size: 16px;
+  font-weight: 700;
+}
+.tag {
+  flex-shrink: 0;
+  height: 20px;
+  padding: 0 6px;
+  border-radius: 3px;
+  font-size: 12px;
+  line-height: 20px;
+  background: var(--learn-soft);
+}
+.link {
+  flex-shrink: 0;
+  color: var(--learn-green-text);
+  font-size: 13px;
+  text-decoration: none;
+  white-space: nowrap;
+}
+.link.small {
+  font-size: 12px;
+}
+.stats {
+  display: grid;
+  grid-template-columns: repeat(4, minmax(0, 1fr));
+  gap: 8px;
+}
+.big {
+  font-size: 22px;
+  font-weight: 700;
+}
+.big.red {
+  color: var(--learn-red-text);
+}
+.unit {
+  font-size: 13px;
+  font-weight: 400;
+  opacity: 0.6;
+}
+.block {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+}
+.errbar {
+  display: flex;
+  gap: 1px;
+  max-width: 440px;
+  height: 10px;
+  border-radius: 4px;
+  overflow: hidden;
+}
+.errtext {
+  gap: 12px;
+  opacity: 0.85;
+}
+.legend {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  white-space: nowrap;
+}
+.legend i {
+  width: 8px;
+  height: 8px;
+  border-radius: 2px;
+}
+.crow {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  white-space: nowrap;
+  height: 32px;
+  border-top: 1px solid var(--learn-line);
+  font-size: 13px;
+}
+.cname {
+  width: 100px;
+  flex-shrink: 0;
+}
+.cusers {
+  width: 40px;
+  text-align: right;
+}
+.cavg {
+  width: 72px;
+}
+.dist {
+  display: flex;
+  align-items: flex-end;
+  gap: 6px;
+}
+.dcol {
+  width: 64px;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 4px;
+}
+.dbar {
+  width: 40px;
+  border-radius: 3px 3px 0 0;
+  background: var(--learn-green-line);
+}
+.dbar.first {
+  background: var(--learn-green);
+}
+.dbar.many {
+  background: var(--learn-orange);
+}
+.names {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
+  column-gap: 24px;
+}
+.nrow {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  white-space: nowrap;
+  height: 28px;
+  font-size: 13px;
+  min-width: 0;
+}
+.uname {
+  width: 110px;
+  flex-shrink: 0;
+}
+.ntries {
+  width: 64px;
+  flex-shrink: 0;
+}
+.hrow {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  white-space: nowrap;
+  height: 24px;
+  font-size: 13px;
+}
+.hlabel {
+  width: 96px;
+  flex-shrink: 0;
+}
+</style>
diff --git a/apps/web/src/admin/problem/Yearly.vue b/apps/web/src/admin/problem/Yearly.vue
new file mode 100644
index 0000000..9245af0
--- /dev/null
+++ b/apps/web/src/admin/problem/Yearly.vue
@@ -0,0 +1,255 @@
+<script setup lang="ts">
+import type { YearlyOverview, YearlySummary } from "utils/types"
+import { getYearlyOverview } from "admin/api"
+import { parseTime } from "utils/functions"
+import "oj/learn/learn.css"
+
+/**
+ * 历年概况（原「年度趋势」，设计稿「卡点与趋势」页的定稿 TrendFinal）：一个学年一列。
+ *
+ * 学年从 9 月 1 日算起（原来按自然年切，一个学年被切成两半）。进行中的学年只有几个月，
+ * 拿它和整年比没有意义，所以旁边并排一列「去年同期」。单道题的历年变化挪进了卡点分析的右栏。
+ * 口径（人 × 题、一次就对、做对之前交了几次）见后端 routes/admin/analytics.ts。
+ */
+const data = ref<YearlyOverview | null>(null)
+const loading = ref(false)
+
+interface Column {
+  key: string
+  title: string
+  sub: string
+  kind: "full" | "current" | "last"
+  row: YearlySummary
+}
+
+function yearLabel(year: number) {
+  return `${String(year).slice(2)}–${String(year + 1).slice(2)}`
+}
+
+/** `until` 是开区间的终点，显示成「到 X 月 X 日」得往前退一毫秒 */
+function untilText(until: string) {
+  return `到 ${parseTime(new Date(Date.parse(until) - 1), "M月D日")}`
+}
+
+const columns = computed<Column[]>(() => {
+  if (!data.value) return []
+  const years = data.value.years
+  const out: Column[] = years.map((row, index) => {
+    const current = index === years.length - 1
+    return {
+      key: String(row.year),
+      title: yearLabel(row.year),
+      sub: current ? untilText(row.until) : "",
+      kind: current ? "current" : "full",
+      row,
+    }
+  })
+  const last = data.value.lastYearToDate
+  if (last)
+    out.push({
+      key: "last",
+      title: "去年同期",
+      sub: `${yearLabel(last.year)} ${untilText(last.until)}`,
+      kind: "last",
+      row: last,
+    })
+  return out
+})
+
+function ratio(part: number, whole: number, digits = 0) {
+  return whole ? Number(((part / whole) * (digits ? 1 : 100)).toFixed(digits)) : 0
+}
+
+interface Line {
+  label: string
+  /** 给人看的 */
+  text: (row: YearlySummary) => string
+  /** 画小横条用的值，只给数量类的行 */
+  value?: (row: YearlySummary) => number
+}
+
+const LINES: Line[] = [
+  {
+    label: "在用的年级",
+    text: (row) => (row.grades.length ? row.grades.map((g) => `${g}`).join(" · ") + " 级" : "-"),
+  },
+  { label: "做题的学生", text: (row) => `${row.users} 人`, value: (row) => row.users },
+  {
+    label: "提交",
+    text: (row) => `${row.submissions.toLocaleString("en-US")} 次`,
+    value: (row) => row.submissions,
+  },
+  { label: "做过的题", text: (row) => `${row.problems} 道`, value: (row) => row.problems },
+  {
+    label: "人均做对",
+    text: (row) => `${ratio(row.solvedPairs, row.users, 1)} 道`,
+    value: (row) => ratio(row.solvedPairs, row.users, 1),
+  },
+  { label: "一次就对", text: (row) => `${ratio(row.firstTryPairs, row.startedPairs)}%` },
+  {
+    label: "做对平均交",
+    text: (row) => (row.solvedStarted ? `${ratio(row.solvedTries, row.solvedStarted, 1)} 次` : "-"),
+  },
+  { label: "C / C++ 提交", text: (row) => `${ratio(row.cSubmissions, row.submissions)}%` },
+]
+
+/** 小横条只在完整学年之间比，进行中的和去年同期都只有几个月 */
+function barWidth(line: Line, column: Column) {
+  if (!line.value || column.kind !== "full") return null
+  const max = Math.max(
+    1,
+    ...columns.value.filter((c) => c.kind === "full").map((c) => line.value!(c.row)),
+  )
+  return `${(line.value(column.row) / max) * 100}%`
+}
+
+function exportCsv() {
+  const quote = (text: string) => `"${text.replaceAll('"', '""')}"`
+  const head = ["", ...columns.value.map((c) => [c.title, c.sub].filter(Boolean).join(" "))]
+  const rows = LINES.map((line) => [line.label, ...columns.value.map((c) => line.text(c.row))])
+  const csv = [head, ...rows].map((row) => row.map(quote).join(",")).join("\r\n")
+  // 带 BOM，Excel 才按 UTF-8 打开，不然中文是乱码
+  const url = URL.createObjectURL(new Blob(["" + csv], { type: "text/csv;charset=utf-8" }))
+  const link = document.createElement("a")
+  link.href = url
+  link.download = "历年概况.csv"
+  link.click()
+  URL.revokeObjectURL(url)
+}
+
+onMounted(async () => {
+  loading.value = true
+  try {
+    data.value = await getYearlyOverview()
+  } finally {
+    loading.value = false
+  }
+})
+</script>
+
+<template>
+  <div class="page">
+    <div class="top">
+      <span class="title">历年概况</span>
+      <span class="grow" />
+      <n-button :disabled="!columns.length" @click="exportCsv">导出表格</n-button>
+    </div>
+    <n-spin :show="loading">
+      <section class="card">
+        <div class="scroll">
+          <table>
+            <thead>
+              <tr>
+                <th class="label muted">学年（9 月起）</th>
+                <th v-for="column in columns" :key="column.key" :class="column.kind">
+                  <div>{{ column.title }}</div>
+                  <div v-if="column.sub" class="sub">{{ column.sub }}</div>
+                </th>
+              </tr>
+            </thead>
+            <tbody>
+              <tr v-for="line in LINES" :key="line.label">
+                <td class="label">{{ line.label }}</td>
+                <td v-for="column in columns" :key="column.key" :class="column.kind" class="num">
+                  <div>{{ line.text(column.row) }}</div>
+                  <div v-if="barWidth(line, column)" class="track">
+                    <span :style="{ width: barWidth(line, column)! }" />
+                  </div>
+                </td>
+              </tr>
+            </tbody>
+          </table>
+        </div>
+      </section>
+    </n-spin>
+  </div>
+</template>
+
+<style scoped>
+.page {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+.top {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+}
+.title {
+  font-size: 20px;
+  font-weight: 700;
+}
+.grow {
+  flex: 1;
+}
+.muted {
+  opacity: 0.6;
+}
+.num {
+  font-variant-numeric: tabular-nums;
+}
+.card {
+  border: 1px solid var(--learn-line);
+  border-radius: 8px;
+  overflow: hidden;
+}
+.scroll {
+  overflow-x: auto;
+}
+table {
+  border-collapse: collapse;
+  width: 100%;
+  min-width: 900px;
+}
+th,
+td {
+  padding: 0 16px;
+  text-align: right;
+  white-space: nowrap;
+}
+th {
+  height: 56px;
+  font-size: 14px;
+  font-weight: 700;
+  vertical-align: bottom;
+  padding-bottom: 10px;
+}
+td {
+  height: 52px;
+  border-top: 1px solid var(--learn-line);
+}
+.label {
+  text-align: left;
+  width: 130px;
+}
+th.label {
+  font-size: 12px;
+  font-weight: 400;
+}
+.sub {
+  font-size: 12px;
+  font-weight: 400;
+  opacity: 0.6;
+}
+.current {
+  font-weight: 700;
+  border-left: 1px solid var(--learn-line);
+}
+.last {
+  opacity: 0.7;
+}
+.track {
+  margin: 4px 0 0 auto;
+  width: 88px;
+  height: 5px;
+  border-radius: 3px;
+  background: var(--learn-todo);
+  overflow: hidden;
+}
+.track > span {
+  display: block;
+  height: 100%;
+  background: var(--learn-green-line);
+}
+</style>
diff --git a/apps/web/src/routes.ts b/apps/web/src/routes.ts
index c7d4911..be294f9 100644
--- a/apps/web/src/routes.ts
+++ b/apps/web/src/routes.ts
@@ -310,11 +310,13 @@ export const admins: RouteRecordRaw = {
       meta: { requiresTeacherAdmin: true },
     },
     {
-      path: "problem/top_ac_trend",
-      name: "admin top ac trend",
-      component: () => import("admin/problem/TopACTrend.vue"),
+      path: "problem/yearly",
+      name: "admin yearly overview",
+      component: () => import("admin/problem/Yearly.vue"),
       meta: { requiresTeacherAdmin: true },
     },
+    // 「年度趋势」改名「历年概况」之前的地址，收藏夹里可能还有
+    { path: "problem/top_ac_trend", redirect: "/admin/problem/yearly" },
     // 题单管理路由
     {
       path: "problemset/list",
diff --git a/apps/web/src/shared/layout/admin.vue b/apps/web/src/shared/layout/admin.vue
index 2323762..84b1ca0 100644
--- a/apps/web/src/shared/layout/admin.vue
+++ b/apps/web/src/shared/layout/admin.vue
@@ -85,9 +85,9 @@ const NAV: NavGroup[] = [
         role: "teacher",
       },
       {
-        label: "年度趋势",
+        label: "历年概况",
         icon: "ph:chart-line-up",
-        path: "/admin/problem/top_ac_trend",
+        path: "/admin/problem/yearly",
         role: "teacher",
       },
       { label: "自学情况", icon: "ph:student", path: "/admin/learn", role: "teacher" },
diff --git a/apps/web/src/utils/types.ts b/apps/web/src/utils/types.ts
index 49a40f2..0ac569c 100644
--- a/apps/web/src/utils/types.ts
+++ b/apps/web/src/utils/types.ts
@@ -328,7 +328,10 @@ export type {
   AdminAiReportListItem,
   AdminAiReportList,
   StuckProblem,
-  AcTrend,
+  StuckProblemDetail,
+  StuckStudent,
+  YearlyOverview,
+  YearlySummary,
   LearnBoard,
   LearnBoardStudent,
   LearnExerciseProgress,