diff --git a/apps/web/src/oj/api.ts b/apps/web/src/oj/api.ts
index bd6fda6..bcfb611 100644
--- a/apps/web/src/oj/api.ts
+++ b/apps/web/src/oj/api.ts
@@ -40,6 +40,7 @@ import {
   type FlowchartStatistics,
   type SubmissionStatistics,
   type SubmissionStatisticsItems,
+  type SubmissionStatisticsGrid,
   type TodaySubmissionStatistics,
 } from "@oj2/contract"
 import api from "utils/api"
@@ -197,6 +198,17 @@ export function getSubmissionStatistics(
   })
 }
 
+/** 统计页的方块串：范围内每个学生的每一次提交（口径见契约 submissionStatisticsGridSchema） */
+export function getSubmissionStatisticsGrid(
+  duration: { start?: string; end: string },
+  problemDisplayId?: string,
+  username?: string,
+) {
+  return api.get<SubmissionStatisticsGrid>("submissions/statistics/grid", {
+    params: { ...duration, problemDisplayId, username },
+  })
+}
+
 /**
  * 全服榜单。上限（100 名）由服务端定，调用方只管翻页 ——
  * 「全服 Top10」就是这个榜的第一页，取 limit=10 即可，不需要另一个上限参数。
diff --git a/apps/web/src/oj/classroom/board.vue b/apps/web/src/oj/classroom/board.vue
index 919e7bc..de2b1e5 100644
--- a/apps/web/src/oj/classroom/board.vue
+++ b/apps/web/src/oj/classroom/board.vue
@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import { getClassBoard, setClassLesson } from "oj/api"
+import { useHiddenStudents } from "shared/composables/hiddenStudents"
 import { useCollabStore } from "shared/store/collab"
 import { useConfigStore } from "shared/store/config"
 import { errorMessage } from "utils/api"
@@ -14,7 +15,7 @@ import type { ClassBoard, ClassBoardCell, ClassBoardStudent } from "utils/types"
  * 没交过 → 卡住 → 在做 → 做完，没交过的名单还单独摆在最上面，老师扫一眼就能走过去。
  *
  * 班级**不记本地**，默认由后端猜最近两小时在交题的班 —— 记本地的话，上一节课的班会
- * 悄悄留在框里，老师看的整个是别人的班。（提交统计弹窗是记一小时的，见 composables/statisticsQuery.ts，
+ * 悄悄留在框里，老师看的整个是别人的班。（原来的提交统计弹窗是记一小时的，
  * 那边是老师自己手选的查询；这里后端本来就猜得出，没必要冒这个险。）
  */
 
@@ -137,14 +138,27 @@ function nameOf(student: ClassBoardStudent) {
   return student.realName || student.username
 }
 
+/**
+ * 请假隐藏（原来在「数据统计」弹框里，统计改成回头看之后挪到这儿 —— 盯这节课的是看板）。
+ * 请假、转班、学号错了的那几个一直挂在「还没交过」里，会盖住真正要去看的人。
+ * 藏两个小时（够一节课），下节课自动回来；只记在这台电脑上，换人换机器都不继承。
+ * 键沿用统计弹框那份，老师上午藏的人这里接着藏着
+ */
+const { hideMode, hideStudent, showAll, isHidden } = useHiddenStudents("oj_hidden_students")
+const hiddenStudents = computed(() =>
+  (board.value?.students ?? []).filter((student) => isHidden(student.username)),
+)
+
 const students = computed(() =>
-  [...(board.value?.students ?? [])].sort(
-    (a, b) =>
-      GROUP_ORDER[groupOf(a)] - GROUP_ORDER[groupOf(b)] ||
-      // 同样是没交过，经常不动手的排前面
-      Number(oftenIdle(b)) - Number(oftenIdle(a)) ||
-      nameOf(a).localeCompare(nameOf(b), "zh-CN"),
-  ),
+  [...(board.value?.students ?? [])]
+    .filter((student) => !isHidden(student.username))
+    .sort(
+      (a, b) =>
+        GROUP_ORDER[groupOf(a)] - GROUP_ORDER[groupOf(b)] ||
+        // 同样是没交过，经常不动手的排前面
+        Number(oftenIdle(b)) - Number(oftenIdle(a)) ||
+        nameOf(a).localeCompare(nameOf(b), "zh-CN"),
+    ),
 )
 
 const idle = computed(() => students.value.filter((student) => groupOf(student) === "idle"))
@@ -164,7 +178,8 @@ const stuckCount = computed(
 )
 
 const summary = computed(() => {
-  const all = board.value?.students ?? []
+  // 分母也减掉请假的，不然「做完 30/38」永远到不了头
+  const all = students.value
   return (board.value?.problems ?? []).map((problem, i) => ({
     ...problem,
     done: all.filter((student) => student.cells[i]?.status === "accepted").length,
@@ -311,20 +326,48 @@ function submissionsHref(student: ClassBoardStudent, problemDisplayId?: string)
 
         <template v-if="!projector">
           <n-alert
-            v-if="idle.length"
+            v-if="idle.length || hiddenStudents.length"
             type="warning"
             :title="`今天还没交过（${idle.length} 人）`"
             class="section"
           >
-            <div v-if="idleOften.length">
-              <b>经常没交</b>（最近 {{ board.recentLessons }} 节课最多交过 1 节）：{{
-                idleOften.map(nameOf).join("、")
-              }}
-            </div>
-            <div v-if="idleOthers.length">
-              <template v-if="idleOften.length"><b>其他</b>：</template
-              >{{ idleOthers.map(nameOf).join("、") }}
-            </div>
+            <n-flex align="center" :size="10" class="hide-bar">
+              <n-switch v-model:value="hideMode" size="small">
+                <template #checked>请假隐藏中 · 点名字旁的 × 藏起来</template>
+                <template #unchecked>请假隐藏</template>
+              </n-switch>
+              <n-button
+                v-if="hiddenStudents.length"
+                size="tiny"
+                text
+                type="primary"
+                @click="showAll"
+              >
+                隐藏了 {{ hiddenStudents.length }} 位：{{ hiddenStudents.map(nameOf).join("、") }} ·
+                恢复
+              </n-button>
+            </n-flex>
+            <n-flex v-if="hideMode" :size="8">
+              <n-tag
+                v-for="student in idle"
+                :key="student.userId"
+                closable
+                @close="hideStudent(student.username)"
+              >
+                {{ nameOf(student) }}
+              </n-tag>
+            </n-flex>
+            <template v-else>
+              <div v-if="idleOften.length">
+                <b>经常没交</b>（最近 {{ board.recentLessons }} 节课最多交过 1 节）：{{
+                  idleOften.map(nameOf).join("、")
+                }}
+              </div>
+              <div v-if="idleOthers.length">
+                <template v-if="idleOften.length"><b>其他</b>：</template
+                >{{ idleOthers.map(nameOf).join("、") }}
+              </div>
+            </template>
           </n-alert>
 
           <n-text v-if="stuckCount" type="error" class="meta">
@@ -420,6 +463,10 @@ function submissionsHref(student: ClassBoardStudent, problemDisplayId?: string)
   text-decoration: underline;
 }
 
+.hide-bar {
+  margin-bottom: 6px;
+}
+
 .board {
   max-width: 1400px;
   margin: 0 auto;
diff --git a/apps/web/src/oj/problem/components/EditorToolbar.vue b/apps/web/src/oj/problem/components/EditorToolbar.vue
index dd86e3c..74eaae1 100644
--- a/apps/web/src/oj/problem/components/EditorToolbar.vue
+++ b/apps/web/src/oj/problem/components/EditorToolbar.vue
@@ -13,7 +13,7 @@ import { Icon } from "@iconify/vue"
 import { NFlex, useThemeVars } from "naive-ui"
 import SubmitCode from "./SubmitCode.vue"
 import { useProblemPageContext } from "../composables/problemPageContext"
-import { statisticsOpen, useEditorMenu } from "../composables/editorMenu"
+import { openStatistics, useEditorMenu } from "../composables/editorMenu"
 import { useTeacherCollab } from "../composables/teacherCollab"
 
 const SubmitFlowchart = defineAsyncComponent(() => import("./SubmitFlowchart.vue"))
@@ -228,7 +228,7 @@ const changeLanguage = (v: LANGUAGE) => {
     <n-button
       v-if="ctx.classStats && statisticsInline && userStore.isTeacherOrAbove"
       :size="buttonSize"
-      @click="statisticsOpen = true"
+      @click="openStatistics(problem!._id)"
     >
       课堂统计
     </n-button>
diff --git a/apps/web/src/oj/problem/composables/editorMenu.ts b/apps/web/src/oj/problem/composables/editorMenu.ts
index a9460c5..0d2b4c1 100644
--- a/apps/web/src/oj/problem/composables/editorMenu.ts
+++ b/apps/web/src/oj/problem/composables/editorMenu.ts
@@ -12,10 +12,12 @@ import { useTeacherCollab } from "./teacherCollab"
 import { useProblemPageContext } from "./problemPageContext"
 
 /**
- * 「课堂统计」弹窗开着没有。弹窗挂在题目页上（StatisticsModal），菜单可能在工具栏里、
- * 也可能在手机页签行的「⋯」里，所以这个开关放在模块级，大家共用一个
+ * 「课堂统计」：新标签打开数据统计页，带上这道题（原来是题目页上的弹框）。
+ * 工具栏按钮和手机页签行的「⋯」都走这一个。新标签是因为老师多半正开着这道题在看
  */
-export const statisticsOpen = ref(false)
+export function openStatistics(problemDisplayId: string) {
+  window.open(`/statistics?problem=${encodeURIComponent(problemDisplayId)}`, "_blank")
+}
 
 /**
  * 编辑器的「更多」菜单：去自测猫 / 复制代码 / 重置代码 / 编辑题目，放不下时再加上课堂统计。
@@ -111,7 +113,7 @@ export function useEditorMenu(statisticsInline: Ref<boolean>) {
   function select(key: string) {
     switch (key) {
       case "statistics":
-        statisticsOpen.value = true
+        openStatistics(problem.value!._id)
         return true
       case "testcat":
         goTestCat()
diff --git a/apps/web/src/oj/problem/detail.vue b/apps/web/src/oj/problem/detail.vue
index 05bcfe2..5e0fa24 100644
--- a/apps/web/src/oj/problem/detail.vue
+++ b/apps/web/src/oj/problem/detail.vue
@@ -15,7 +15,6 @@ import type { RouteLocationNormalized } from "vue-router"
 import SubmissionEffects from "./components/SubmissionEffects.vue"
 import ResultTabLabel from "./components/ResultTabLabel.vue"
 import ContextBar from "./components/ContextBar.vue"
-import StatisticsModal from "./components/StatisticsModal.vue"
 import { useEditorMenu } from "./composables/editorMenu"
 import {
   DRAWER_TITLE,
@@ -255,7 +254,6 @@ onBeforeUnmount(() => {
 <template>
   <template v-if="problem">
     <SubmissionEffects />
-    <StatisticsModal />
     <!--
       桌面：两栏顶满整个内容区（设计稿「机房（方案 B）」），中间一条 1px 分隔线、可拖动。
       布局给内容区留了 16px 内边距，这里用负边距抵掉
diff --git a/apps/web/src/oj/statistics/components/AttemptSquares.vue b/apps/web/src/oj/statistics/components/AttemptSquares.vue
new file mode 100644
index 0000000..c79fabb
--- /dev/null
+++ b/apps/web/src/oj/statistics/components/AttemptSquares.vue
@@ -0,0 +1,163 @@
+<script lang="ts">
+import type { Submission } from "utils/types"
+
+/**
+ * 代码按提交 id 缓存，整页共用：交了就不会再变，老师在一排方块之间来回对比时
+ * 不用每次都等网络。失败的不进缓存，下次停上去再试。
+ */
+const codeCache = new Map<string, Submission>()
+</script>
+
+<script setup lang="ts">
+import { getSubmission } from "oj/api"
+import { JUDGE_STATUS, LANGUAGE_FORMAT_VALUE, SubmissionStatus } from "utils/constants"
+import { parseTime } from "utils/functions"
+import type { SUBMISSION_RESULT } from "utils/types"
+import { useTone, type Tone } from "oj/submission/composables/tone"
+
+/**
+ * 一个人在一道题上的每一次提交，一格一次、从早到晚（设计稿「统计重设计」）。
+ * 鼠标停在一格上看那一次的代码，点一下新页面打开那条提交。
+ */
+const props = withDefaults(
+  defineProps<{
+    items: Array<{ id: string; result: SUBMISSION_RESULT; createTime: string }>
+    size?: number
+  }>(),
+  { size: 14 },
+)
+
+const tone = useTone()
+
+function toneOf(result: number): Tone {
+  if (result === SubmissionStatus.accepted) return "success"
+  if (
+    result === SubmissionStatus.compile_error ||
+    result === SubmissionStatus.runtime_error ||
+    result === SubmissionStatus.ast_check_failed ||
+    result === SubmissionStatus.partial_accepted
+  ) {
+    return "warning"
+  }
+  if (result === SubmissionStatus.pending || result === SubmissionStatus.judging) return "info"
+  return "error"
+}
+
+const code = reactive<Record<string, Submission | "loading" | "failed">>({})
+
+async function load(id: string) {
+  const hit = codeCache.get(id)
+  if (hit) {
+    code[id] = hit
+    return
+  }
+  if (code[id] === "loading") return
+  code[id] = "loading"
+  try {
+    const res = await getSubmission(id)
+    codeCache.set(id, res)
+    code[id] = res
+  } catch {
+    code[id] = "failed"
+  }
+}
+
+function open(id: string) {
+  window.open("/submission/" + id, "_blank", "noopener")
+}
+
+const cells = computed(() =>
+  props.items.map((item, index) => ({
+    ...item,
+    index: index + 1,
+    color: tone(toneOf(item.result)).solid,
+  })),
+)
+</script>
+
+<template>
+  <span class="squares">
+    <n-popover
+      v-for="cell in cells"
+      :key="cell.id"
+      :delay="200"
+      :style="{ maxWidth: '560px' }"
+      @update:show="(show: boolean) => show && load(cell.id)"
+    >
+      <template #trigger>
+        <button
+          class="square"
+          :style="{ width: `${size}px`, height: `${size}px`, background: cell.color }"
+          :aria-label="`第 ${cell.index} 次：${JUDGE_STATUS[cell.result]?.name ?? ''}`"
+          @click.stop="open(cell.id)"
+        ></button>
+      </template>
+      <div class="pop">
+        <div class="pop-head">
+          <b>{{ JUDGE_STATUS[cell.result]?.name }}</b>
+          <span class="muted"
+            >{{ parseTime(cell.createTime, "M月D日 HH:mm") }} · 第 {{ cell.index }} 次</span
+          >
+        </div>
+        <n-code
+          v-if="typeof code[cell.id] === 'object'"
+          class="pop-code"
+          :code="(code[cell.id] as Submission).code"
+          :language="LANGUAGE_FORMAT_VALUE[(code[cell.id] as Submission).language]"
+          show-line-numbers
+        />
+        <span v-else-if="code[cell.id] === 'failed'" class="muted">代码没拉下来，点方块打开看</span>
+        <span v-else class="muted">代码加载中…</span>
+        <span class="muted small">点方块在新页面打开这一条</span>
+      </div>
+    </n-popover>
+  </span>
+</template>
+
+<style scoped>
+.squares {
+  display: inline-flex;
+  flex-wrap: wrap;
+  gap: 4px;
+  align-items: center;
+}
+
+.square {
+  flex: none;
+  padding: 0;
+  border: 0;
+  border-radius: 3px;
+  cursor: pointer;
+}
+
+.square:hover {
+  outline: 2px solid currentColor;
+  outline-offset: 1px;
+}
+
+.pop {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.pop-head {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+.pop-code {
+  max-height: 360px;
+  overflow: auto;
+  font-size: 14px;
+}
+
+.muted {
+  opacity: 0.65;
+}
+
+.small {
+  font-size: 12px;
+}
+</style>
diff --git a/apps/web/src/oj/statistics/components/ByClass.vue b/apps/web/src/oj/statistics/components/ByClass.vue
new file mode 100644
index 0000000..1dd041f
--- /dev/null
+++ b/apps/web/src/oj/statistics/components/ByClass.vue
@@ -0,0 +1,204 @@
+<script setup lang="ts">
+import { useThemeVars } from "naive-ui"
+import type { SubmissionStatisticsGrid } from "@oj2/contract"
+import { SubmissionStatus } from "utils/constants"
+import { useTone } from "oj/submission/composables/tone"
+import { classLabel, submissionDayText } from "oj/submission/utils"
+
+/**
+ * 没选班级、也没填学生时（多半是从题目页进来，只带了题号）：先按班级列出来，
+ * 点一个班再看人。「一道没交」要花名册人数，后端在这种情况下给 classSizes。
+ */
+const props = defineProps<{ grid: SubmissionStatisticsGrid }>()
+const emit = defineEmits<{ pick: [className: string] }>()
+
+const theme = useThemeVars()
+const tone = useTone()
+
+function isAc(result: number) {
+  return result === SubmissionStatus.accepted || result === SubmissionStatus.ast_check_failed
+}
+
+const classes = computed(() => {
+  const need = props.grid.problems.map((problem) => problem.problemDisplayId)
+  const groups = new Map<string, SubmissionStatisticsGrid["rows"]>()
+  for (const row of props.grid.rows) {
+    const key = row.className ?? ""
+    groups.set(key, [...(groups.get(key) ?? []), row])
+  }
+  return [...groups.entries()]
+    .map(([className, rows]) => {
+      let submissions = 0
+      let accepted = 0
+      let last = ""
+      let done = 0
+      for (const row of rows) {
+        const solved = new Set(
+          row.submissions.filter((item) => isAc(item.result)).map((item) => item.problemDisplayId),
+        )
+        if (need.every((pid) => solved.has(pid))) done++
+        submissions += row.submissions.length
+        accepted += row.submissions.filter((item) => isAc(item.result)).length
+        const lastTime = row.submissions.at(-1)?.createTime ?? ""
+        if (lastTime > last) last = lastTime
+      }
+      const size = props.grid.classSizes[className] ?? rows.length
+      return {
+        className,
+        label: className ? classLabel(className) : "没有班级",
+        size,
+        done,
+        tried: rows.length - done,
+        none: Math.max(0, size - rows.length),
+        rate: submissions ? `${Math.round((accepted / submissions) * 100)}%` : "—",
+        last,
+      }
+    })
+    .sort((a, b) => b.last.localeCompare(a.last))
+})
+</script>
+
+<template>
+  <div class="by-class">
+    <div class="cols">
+      <span class="c-class">班级</span>
+      <span class="c-done">做完</span>
+      <span class="c-n">交了没对</span>
+      <span class="c-n">没交</span>
+      <span class="c-n">正确率</span>
+      <span class="c-last">最近一次</span>
+      <span class="spacer"></span>
+    </div>
+    <div class="rows">
+      <div v-for="row in classes" :key="row.className" class="row">
+        <b class="c-class">{{ row.label }}</b>
+        <span class="c-done">
+          <span class="bar">
+            <span
+              class="fill"
+              :style="{ width: `${row.size ? (row.done / row.size) * 100 : 0}%` }"
+            ></span>
+          </span>
+          <span class="num">{{ row.done }}/{{ row.size }}</span>
+        </span>
+        <span class="c-n" :style="{ color: tone('warning').color }">{{ row.tried }}</span>
+        <span class="c-n" :style="{ color: tone('error').color }">{{ row.none }}</span>
+        <span class="c-n muted">{{ row.rate }}</span>
+        <span class="c-last muted">{{ row.last ? submissionDayText(row.last) : "—" }}</span>
+        <span class="spacer"></span>
+        <n-button
+          v-if="row.className"
+          size="small"
+          text
+          type="primary"
+          @click="emit('pick', row.className)"
+        >
+          看这个班 →
+        </n-button>
+      </div>
+      <div v-if="!classes.length" class="empty">这段时间没有人交</div>
+      <p class="note">没选班级，先按班级列出来；点一个班再看每个人。「做完」是这几道题都做对了。</p>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.by-class {
+  flex: 1 1 0;
+  min-height: 0;
+  display: flex;
+  flex-direction: column;
+}
+
+.cols {
+  height: 32px;
+  flex: none;
+  box-sizing: border-box;
+  padding: 0 20px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  font-size: 12px;
+  color: v-bind("theme.textColor3");
+  background: v-bind("theme.actionColor");
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+}
+
+.rows {
+  flex: 1 1 0;
+  min-height: 0;
+  overflow-y: auto;
+}
+
+.row {
+  height: 44px;
+  box-sizing: border-box;
+  padding: 0 20px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+}
+
+.c-class {
+  width: 140px;
+  flex: none;
+}
+
+.c-done {
+  width: 240px;
+  flex: none;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+.c-n {
+  width: 90px;
+  flex: none;
+}
+
+.c-last {
+  width: 110px;
+  flex: none;
+}
+
+.bar {
+  width: 150px;
+  height: 6px;
+  border-radius: 3px;
+  background: v-bind("theme.dividerColor");
+  overflow: hidden;
+}
+
+.fill {
+  display: block;
+  height: 6px;
+  background: v-bind("theme.successColor");
+}
+
+.num {
+  font-variant-numeric: tabular-nums;
+}
+
+.muted {
+  color: v-bind("theme.textColor3");
+}
+
+.spacer {
+  flex: 1 1 0;
+}
+
+.empty {
+  padding: 40px 16px;
+  text-align: center;
+  color: v-bind("theme.textColor3");
+}
+
+.note {
+  margin: 0;
+  padding: 10px 20px;
+  font-size: 12px;
+  color: v-bind("theme.textColor3");
+}
+</style>
diff --git a/apps/web/src/oj/statistics/components/CodeStats.vue b/apps/web/src/oj/statistics/components/CodeStats.vue
new file mode 100644
index 0000000..78311bd
--- /dev/null
+++ b/apps/web/src/oj/statistics/components/CodeStats.vue
@@ -0,0 +1,698 @@
+<script setup lang="ts">
+import { Icon } from "@iconify/vue"
+import { useThemeVars } from "naive-ui"
+import type { SubmissionStatistics, SubmissionStatisticsGrid } from "@oj2/contract"
+import { SubmissionStatus } from "utils/constants"
+import { parseTime } from "utils/functions"
+import StatusPill from "oj/submission/components/StatusPill.vue"
+import { useTone } from "oj/submission/composables/tone"
+import AttemptSquares from "./AttemptSquares.vue"
+
+/**
+ * 代码统计的主体（设计稿「统计重设计 · 定稿 B」）：左边题目，右边学生。
+ * 选一道题看全班每人在这道题上的每一次；选「全部」看每人几道做完、展开按题看。
+ *
+ * 数字口径（做完、没交）跟着统计接口走（stats），这里的方块串和每题做完几人
+ * 从 grid 里的逐条提交算。
+ */
+const props = defineProps<{
+  stats: SubmissionStatistics
+  grid: SubmissionStatisticsGrid
+}>()
+
+const theme = useThemeVars()
+const tone = useTone()
+
+type Attempt = SubmissionStatisticsGrid["rows"][number]["submissions"][number]
+
+function isAc(result: number) {
+  return result === SubmissionStatus.accepted || result === SubmissionStatus.ast_check_failed
+}
+
+interface Student {
+  username: string
+  name: string
+  /** 题号 → 这道题上的每一次，从早到晚 */
+  byProblem: Map<string, Attempt[]>
+  total: number
+  accepted: number
+  last: string | null
+}
+
+/** 花名册上的每一个人：交过的从 grid 来，一条没交的从统计接口的 dataUnaccepted 来 */
+const students = computed<Student[]>(() => {
+  const list: Student[] = props.grid.rows.map((row) => {
+    const byProblem = new Map<string, Attempt[]>()
+    for (const item of row.submissions) {
+      const bucket = byProblem.get(item.problemDisplayId) ?? []
+      bucket.push(item)
+      byProblem.set(item.problemDisplayId, bucket)
+    }
+    return {
+      username: row.username,
+      name: row.realName || row.username,
+      byProblem,
+      total: row.submissions.length,
+      accepted: row.submissions.filter((item) => isAc(item.result)).length,
+      last: row.submissions.at(-1)?.createTime ?? null,
+    }
+  })
+  const seen = new Set(list.map((item) => item.username))
+  for (const row of props.stats.dataUnaccepted) {
+    if (seen.has(row.username)) continue
+    list.push({
+      username: row.username,
+      name: row.realName || row.username,
+      byProblem: new Map(),
+      total: 0,
+      accepted: 0,
+      last: null,
+    })
+  }
+  return list
+})
+
+const problems = computed(() => props.grid.problems)
+const personCount = computed(() => props.stats.personCount || students.value.length)
+
+function solvedOn(student: Student, pid: string) {
+  return (student.byProblem.get(pid) ?? []).some((item) => isAc(item.result))
+}
+
+function doneCount(student: Student) {
+  return problems.value.filter((problem) => solvedOn(student, problem.problemDisplayId)).length
+}
+
+const problemRows = computed(() =>
+  problems.value.map((problem) => {
+    const pid = problem.problemDisplayId
+    const tried = students.value.filter((student) => student.byProblem.has(pid))
+    const done = tried.filter((student) => solvedOn(student, pid)).length
+    const attempts = tried.reduce((sum, student) => sum + student.byProblem.get(pid)!.length, 0)
+    return {
+      ...problem,
+      done,
+      tried: tried.length,
+      avg: tried.length ? (attempts / tried.length).toFixed(1) : "—",
+    }
+  }),
+)
+
+const allDone = computed(
+  () => students.value.filter((student) => doneCount(student) === problems.value.length).length,
+)
+
+// ---------- 选中哪道题、筛哪些人 ----------
+
+/** "" = 全部。只有一道题时直接选中它 */
+const focus = ref("")
+watch(
+  problems,
+  (list) => {
+    if (list.length === 1) focus.value = list[0]!.problemDisplayId
+    else if (!list.some((problem) => problem.problemDisplayId === focus.value)) focus.value = ""
+  },
+  { immediate: true },
+)
+
+/** 默认只看没做完的：复盘要找的是他们，做完的一长串沉在下面也看不见 */
+const onlyUnfinished = ref(true)
+
+const focusRow = computed(() =>
+  problemRows.value.find((row) => row.problemDisplayId === focus.value),
+)
+
+/** 这道题上：没过的在前（交得越多越靠前 —— 卡得最久），一次没交的其次，做完的沉底 */
+const problemStudents = computed(() => {
+  const pid = focus.value
+  const list = students.value.map((student) => {
+    const items = student.byProblem.get(pid) ?? []
+    return { student, items, solved: items.some((item) => isAc(item.result)) }
+  })
+  const rank = (row: (typeof list)[number]) => (row.solved ? 2 : row.items.length ? 0 : 1)
+  return list
+    .filter((row) => !onlyUnfinished.value || !row.solved)
+    .sort(
+      (a, b) =>
+        rank(a) - rank(b) ||
+        b.items.length - a.items.length ||
+        a.student.name.localeCompare(b.student.name, "zh-CN"),
+    )
+})
+
+/** 全部题：没做完的在前（交得多的更前），一道没交的其次，全做完的沉底 */
+const allStudents = computed(() => {
+  const n = problems.value.length
+  const list = students.value.map((student) => ({ student, done: doneCount(student) }))
+  const rank = (row: (typeof list)[number]) => (row.done === n ? 2 : row.student.total ? 0 : 1)
+  return list
+    .filter((row) => !onlyUnfinished.value || row.done < n)
+    .sort(
+      (a, b) =>
+        rank(a) - rank(b) ||
+        b.student.total - a.student.total ||
+        a.student.name.localeCompare(b.student.name, "zh-CN"),
+    )
+})
+
+const unfinishedCount = computed(() =>
+  focus.value
+    ? students.value.filter((student) => !solvedOn(student, focus.value)).length
+    : students.value.filter((student) => doneCount(student) < problems.value.length).length,
+)
+
+const expanded = ref("")
+watch([focus, onlyUnfinished], () => (expanded.value = ""))
+
+function toggle(username: string) {
+  expanded.value = expanded.value === username ? "" : username
+}
+
+/** 展开一个人：没过的题在前、交得多的更前 */
+function problemsOf(student: Student) {
+  return [...problems.value].sort((a, b) => {
+    const sa = solvedOn(student, a.problemDisplayId)
+    const sb = solvedOn(student, b.problemDisplayId)
+    if (sa !== sb) return sa ? 1 : -1
+    return (
+      (student.byProblem.get(b.problemDisplayId)?.length ?? 0) -
+      (student.byProblem.get(a.problemDisplayId)?.length ?? 0)
+    )
+  })
+}
+
+function rate(student: Student) {
+  return student.total ? `${Math.round((student.accepted / student.total) * 100)}%` : "—"
+}
+
+function dayText(time: string | null) {
+  return time ? parseTime(time, "M月D日 HH:mm") : "—"
+}
+
+function pct(done: number, total: number) {
+  return total > 0 ? `${Math.min(100, (done / total) * 100)}%` : "0%"
+}
+</script>
+
+<template>
+  <div class="code-stats">
+    <!-- 左：题目 -->
+    <section class="problems">
+      <div class="col-head">题目（按你填的顺序）</div>
+      <div class="problem-list">
+        <button
+          v-if="problems.length > 1"
+          class="problem"
+          :class="{ on: focus === '' }"
+          @click="focus = ''"
+        >
+          <span class="p-line">
+            <b>全部 {{ problems.length }} 道</b>
+            <span class="spacer"></span>
+            <span class="muted">做完 {{ allDone }}/{{ personCount }} 人</span>
+          </span>
+          <span class="bar"
+            ><span class="fill" :style="{ width: pct(allDone, personCount) }"></span
+          ></span>
+        </button>
+        <button
+          v-for="row in problemRows"
+          :key="row.problemDisplayId"
+          class="problem"
+          :class="{ on: focus === row.problemDisplayId }"
+          @click="focus = row.problemDisplayId"
+        >
+          <span class="p-line">
+            <span class="muted">{{ row.problemDisplayId }}</span>
+            <b class="p-title">{{ row.title }}</b>
+            <span class="spacer"></span>
+            <span class="muted">做完 {{ row.done }}/{{ personCount }} · 平均 {{ row.avg }} 次</span>
+          </span>
+          <span class="bar"
+            ><span class="fill" :style="{ width: pct(row.done, personCount) }"></span
+          ></span>
+        </button>
+        <div v-if="!problems.length" class="empty">这段时间没有人交</div>
+      </div>
+    </section>
+
+    <!-- 右：学生 -->
+    <section class="students">
+      <div class="s-head">
+        <template v-if="focusRow">
+          <b class="s-title">{{ focusRow.problemDisplayId }} {{ focusRow.title }}</b>
+          <span class="muted">
+            做完 {{ focusRow.done }}/{{ personCount }} · 交了没对
+            {{ focusRow.tried - focusRow.done }} · 没交
+            {{ Math.max(0, personCount - focusRow.tried) }}
+          </span>
+        </template>
+        <template v-else>
+          <b class="s-title">全部 {{ problems.length }} 道</b>
+          <span class="muted">
+            做完 {{ allDone }}/{{ personCount }} · 没做完 {{ unfinishedCount }} · 一道没交
+            {{ stats.dataUnaccepted.length }}
+          </span>
+        </template>
+        <span class="spacer"></span>
+        <button class="chip" :class="{ on: onlyUnfinished }" @click="onlyUnfinished = true">
+          没做完 <span class="n">{{ unfinishedCount }}</span>
+        </button>
+        <button class="chip" :class="{ on: !onlyUnfinished }" @click="onlyUnfinished = false">
+          全部 <span class="n">{{ students.length }}</span>
+        </button>
+      </div>
+
+      <!-- 一道题：每人一行，后面是这道题上的每一次 -->
+      <template v-if="focusRow">
+        <div class="cols">
+          <span class="c-name">学生</span>
+          <span class="c-last">最后一次</span>
+          <span class="c-n">次数</span>
+          <span class="c-seq">每一次（从早到晚）</span>
+          <span class="c-when">最近一次在</span>
+        </div>
+        <div class="rows">
+          <div v-for="row in problemStudents" :key="row.student.username" class="row">
+            <span class="c-name name" :title="row.student.username">{{ row.student.name }}</span>
+            <span class="c-last">
+              <StatusPill v-if="row.items.length" :result="row.items.at(-1)!.result" />
+              <b v-else class="none" :style="{ color: tone('error').color }">没交</b>
+            </span>
+            <span class="c-n muted">{{ row.items.length || "—" }}</span>
+            <span class="c-seq"><AttemptSquares :items="row.items" /></span>
+            <span class="c-when muted">{{ dayText(row.items.at(-1)?.createTime ?? null) }}</span>
+          </div>
+          <div v-if="!problemStudents.length" class="empty">全都做完了</div>
+        </div>
+      </template>
+
+      <!-- 全部题：每人一行，一格一道题；点开按题看方块串 -->
+      <template v-else>
+        <div class="cols">
+          <span class="c-caret"></span>
+          <span class="c-name">学生</span>
+          <span class="c-done">做完</span>
+          <span class="c-n">提交</span>
+          <span class="c-rate">正确率</span>
+          <span class="c-grid">{{ problems.map((p) => p.problemDisplayId).join(" · ") }}</span>
+        </div>
+        <div class="rows">
+          <template v-for="row in allStudents" :key="row.student.username">
+            <div
+              class="row clickable"
+              :class="{ on: expanded === row.student.username }"
+              @click="toggle(row.student.username)"
+            >
+              <span class="c-caret">
+                <Icon
+                  :icon="
+                    expanded === row.student.username ? 'ph:caret-down-bold' : 'ph:caret-right-bold'
+                  "
+                  :width="12"
+                />
+              </span>
+              <span class="c-name name" :title="row.student.username">{{ row.student.name }}</span>
+              <span
+                class="c-done done"
+                :style="{
+                  color:
+                    row.done === problems.length
+                      ? tone('success').color
+                      : row.student.total
+                        ? theme.textColor1
+                        : tone('error').color,
+                }"
+              >
+                {{ row.done }}/{{ problems.length }}
+              </span>
+              <span class="c-n muted">{{ row.student.total }}</span>
+              <span class="c-rate muted">{{ rate(row.student) }}</span>
+              <span class="c-grid cells">
+                <span
+                  v-for="problem in problems"
+                  :key="problem.problemDisplayId"
+                  class="cell"
+                  :title="problem.problemDisplayId + ' ' + problem.title"
+                  :style="
+                    solvedOn(row.student, problem.problemDisplayId)
+                      ? { background: tone('success').solid, color: '#fff' }
+                      : row.student.byProblem.has(problem.problemDisplayId)
+                        ? { background: tone('error').background, color: tone('error').color }
+                        : { background: theme.actionColor, color: theme.textColor3 }
+                  "
+                >
+                  {{
+                    solvedOn(row.student, problem.problemDisplayId)
+                      ? "✓"
+                      : (row.student.byProblem.get(problem.problemDisplayId)?.length ?? "·")
+                  }}
+                </span>
+              </span>
+            </div>
+            <div v-if="expanded === row.student.username" class="detail">
+              <div
+                v-for="problem in problemsOf(row.student)"
+                :key="problem.problemDisplayId"
+                class="d-line"
+              >
+                <span class="d-title"
+                  ><span class="muted">{{ problem.problemDisplayId }}</span>
+                  {{ problem.title }}</span
+                >
+                <span
+                  class="d-state"
+                  :style="{
+                    color: solvedOn(row.student, problem.problemDisplayId)
+                      ? tone('success').color
+                      : tone('error').color,
+                  }"
+                >
+                  {{ row.student.byProblem.get(problem.problemDisplayId)?.length ?? 0 }} 次 ·
+                  {{
+                    solvedOn(row.student, problem.problemDisplayId)
+                      ? "已通过"
+                      : row.student.byProblem.has(problem.problemDisplayId)
+                        ? "还没过"
+                        : "没交"
+                  }}
+                </span>
+                <AttemptSquares
+                  :items="row.student.byProblem.get(problem.problemDisplayId) ?? []"
+                />
+              </div>
+            </div>
+          </template>
+          <div v-if="!allStudents.length" class="empty">全都做完了</div>
+        </div>
+      </template>
+      <div v-if="grid.truncated" class="truncated">
+        范围太大，方块串只画了最近 5000 条；上面的人数、正确率仍是全部算的。
+      </div>
+    </section>
+  </div>
+</template>
+
+<style scoped>
+.code-stats {
+  flex: 1 1 0;
+  min-height: 0;
+  display: flex;
+}
+
+.problems {
+  width: 380px;
+  flex: none;
+  display: flex;
+  flex-direction: column;
+  border-right: 1px solid v-bind("theme.dividerColor");
+  min-height: 0;
+}
+
+.col-head {
+  height: 36px;
+  flex: none;
+  box-sizing: border-box;
+  padding: 0 16px 0 20px;
+  display: flex;
+  align-items: center;
+  font-size: 12px;
+  color: v-bind("theme.textColor3");
+  background: v-bind("theme.actionColor");
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+}
+
+.problem-list {
+  flex: 1 1 0;
+  min-height: 0;
+  overflow-y: auto;
+}
+
+.problem {
+  width: 100%;
+  height: 50px;
+  box-sizing: border-box;
+  padding: 0 16px 0 20px;
+  display: flex;
+  flex-direction: column;
+  justify-content: center;
+  gap: 6px;
+  border: 0;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+  background: transparent;
+  font: inherit;
+  color: inherit;
+  text-align: left;
+  cursor: pointer;
+}
+
+.problem:hover {
+  background: v-bind("theme.hoverColor");
+}
+
+.problem.on {
+  background: v-bind("tone('success').background");
+}
+
+.p-line {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  white-space: nowrap;
+  min-width: 0;
+}
+
+.p-title {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  min-width: 0;
+}
+
+.bar {
+  height: 4px;
+  border-radius: 2px;
+  background: v-bind("theme.dividerColor");
+  overflow: hidden;
+}
+
+.fill {
+  display: block;
+  height: 4px;
+  border-radius: 2px;
+  background: v-bind("theme.successColor");
+}
+
+.muted {
+  color: v-bind("theme.textColor3");
+  font-size: 12px;
+}
+
+.spacer {
+  flex: 1 1 0;
+}
+
+.students {
+  flex: 1 1 0;
+  min-width: 0;
+  min-height: 0;
+  display: flex;
+  flex-direction: column;
+}
+
+.s-head {
+  height: 44px;
+  flex: none;
+  box-sizing: border-box;
+  padding: 0 20px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+  white-space: nowrap;
+}
+
+.s-title {
+  font-size: 15px;
+}
+
+.chip {
+  height: 28px;
+  padding: 0 12px;
+  border: 1px solid v-bind("theme.borderColor");
+  border-radius: 14px;
+  background: transparent;
+  font: inherit;
+  font-size: 13px;
+  color: v-bind("theme.textColor2");
+  cursor: pointer;
+}
+
+.chip.on {
+  border-color: v-bind("theme.primaryColor");
+  background: v-bind("tone('success').background");
+  color: v-bind("tone('success').color");
+  font-weight: 600;
+}
+
+.chip .n {
+  opacity: 0.75;
+  font-weight: 400;
+}
+
+.cols {
+  height: 32px;
+  flex: none;
+  box-sizing: border-box;
+  padding: 0 20px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  font-size: 12px;
+  color: v-bind("theme.textColor3");
+  background: v-bind("theme.actionColor");
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+}
+
+.rows {
+  flex: 1 1 0;
+  min-height: 0;
+  overflow-y: auto;
+}
+
+.row {
+  min-height: 38px;
+  box-sizing: border-box;
+  padding: 6px 20px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+}
+
+.row.clickable {
+  cursor: pointer;
+}
+
+.row.clickable:hover {
+  background: v-bind("theme.hoverColor");
+}
+
+.row.on {
+  background: v-bind("tone('success').background");
+}
+
+.c-caret {
+  width: 16px;
+  flex: none;
+  display: flex;
+  color: v-bind("theme.textColor3");
+}
+.c-name {
+  width: 110px;
+  flex: none;
+}
+.c-last {
+  width: 120px;
+  flex: none;
+}
+.c-n {
+  width: 50px;
+  flex: none;
+}
+.c-seq {
+  flex: 1 1 0;
+  min-width: 0;
+}
+.c-when {
+  width: 100px;
+  flex: none;
+}
+.c-done {
+  width: 60px;
+  flex: none;
+}
+.c-rate {
+  width: 60px;
+  flex: none;
+}
+.c-grid {
+  flex: 1 1 0;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.name {
+  font-weight: 600;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.done {
+  font-weight: 600;
+  font-variant-numeric: tabular-nums;
+}
+
+.none {
+  font-size: 13px;
+}
+
+.cells {
+  display: flex;
+  gap: 4px;
+  flex-wrap: wrap;
+  white-space: normal;
+}
+
+.cell {
+  width: 30px;
+  height: 18px;
+  border-radius: 4px;
+  font-size: 11px;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.detail {
+  padding: 6px 20px 8px 46px;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+  background: v-bind("theme.actionColor");
+}
+
+.d-line {
+  min-height: 28px;
+  display: flex;
+  align-items: center;
+  gap: 12px;
+}
+
+.d-title {
+  width: 190px;
+  flex: none;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.d-state {
+  width: 100px;
+  flex: none;
+  font-size: 12px;
+}
+
+.empty {
+  padding: 40px 16px;
+  text-align: center;
+  color: v-bind("theme.textColor3");
+}
+
+.truncated {
+  padding: 8px 20px;
+  font-size: 12px;
+  color: v-bind("tone('warning').color");
+  border-top: 1px solid v-bind("theme.dividerColor");
+}
+</style>
diff --git a/apps/web/src/oj/statistics/components/FlowStats.vue b/apps/web/src/oj/statistics/components/FlowStats.vue
new file mode 100644
index 0000000..4ba0d45
--- /dev/null
+++ b/apps/web/src/oj/statistics/components/FlowStats.vue
@@ -0,0 +1,450 @@
+<script setup lang="ts">
+import {
+  ArcElement,
+  BarElement,
+  CategoryScale,
+  Chart as ChartJS,
+  Filler,
+  Legend,
+  LinearScale,
+  LineElement,
+  PointElement,
+  RadialLinearScale,
+  Tooltip,
+} from "chart.js"
+import { WordCloudController, WordElement } from "chartjs-chart-wordcloud"
+import { useThemeVars } from "naive-ui"
+import { Bar, Doughnut, Radar } from "vue-chartjs"
+import type { FlowchartStatistics } from "@oj2/contract"
+import { useChartTheme } from "shared/composables/chartTheme"
+import { FLOWCHART_CRITERIA_ORDER } from "utils/constants"
+import { useTone } from "oj/submission/composables/tone"
+import RingChart from "./RingChart.vue"
+import StatItem from "./StatItem.vue"
+
+ChartJS.register(
+  ArcElement,
+  BarElement,
+  CategoryScale,
+  Filler,
+  Legend,
+  LinearScale,
+  LineElement,
+  PointElement,
+  RadialLinearScale,
+  Tooltip,
+  WordCloudController,
+  WordElement,
+)
+
+/**
+ * 流程图统计（设计稿「统计重设计 · 流程图」）：等级分布、四项评分、各项平均分、
+ * 高频问题词云、每人最好的一次。图表都是 chart.js，和站里别的图一套主题。
+ */
+const props = defineProps<{ data: FlowchartStatistics }>()
+
+const theme = useThemeVars()
+const tone = useTone()
+const { chartKey } = useChartTheme()
+
+const GRADES = ["S", "A", "B", "C"] as const
+const gradeColor = computed(() => ({
+  S: tone("success").solid,
+  A: tone("info").solid,
+  B: tone("warning").solid,
+  C: tone("error").solid,
+}))
+
+/** 拿到 A / S 算完成（和题单、课堂条的口径一致） */
+const goodCount = computed(
+  () => props.data.people.filter((row) => row.bestGrade === "S" || row.bestGrade === "A").length,
+)
+const personCount = computed(() => props.data.personCount || props.data.people.length)
+
+const gradeData = computed(() => ({
+  labels: GRADES.map((grade) => `${grade} 级`),
+  datasets: [
+    {
+      data: GRADES.map((grade) => props.data.gradeDistribution[grade] ?? 0),
+      backgroundColor: GRADES.map((grade) => gradeColor.value[grade]),
+      borderWidth: 0,
+    },
+  ],
+}))
+
+const gradeOptions = {
+  responsive: true,
+  maintainAspectRatio: false,
+  cutout: "60%",
+  plugins: { legend: { position: "right" as const } },
+}
+
+/** 四项按固定顺序（jsonb 不保留键序，逻辑正确性要在最前） */
+const criteria = computed(() =>
+  FLOWCHART_CRITERIA_ORDER.filter((key) => props.data.criteriaAverages[key]).map((key) => ({
+    key,
+    ...props.data.criteriaAverages[key]!,
+  })),
+)
+
+const radarData = computed(() => ({
+  labels: criteria.value.map((item) => item.key),
+  datasets: [
+    {
+      label: "平均得分率",
+      data: criteria.value.map((item) => Math.round((item.avg / (item.max || 1)) * 100)),
+      backgroundColor: "rgba(32, 128, 240, 0.18)",
+      borderColor: tone("info").solid,
+      pointBackgroundColor: tone("info").solid,
+      fill: true,
+    },
+  ],
+}))
+
+const radarOptions = {
+  responsive: true,
+  maintainAspectRatio: false,
+  plugins: {
+    legend: { display: false },
+    tooltip: {
+      callbacks: { label: (context: { parsed: { r: number } }) => `${context.parsed.r}%` },
+    },
+  },
+  scales: { r: { min: 0, max: 100, ticks: { stepSize: 25, display: false } } },
+}
+
+const barData = computed(() => ({
+  labels: criteria.value.map((item) => item.key),
+  datasets: [
+    {
+      label: "平均分",
+      data: criteria.value.map((item) => item.avg),
+      backgroundColor: tone("info").solid,
+      borderRadius: 4,
+    },
+  ],
+}))
+
+const barOptions = computed(() => ({
+  indexAxis: "y" as const,
+  responsive: true,
+  maintainAspectRatio: false,
+  plugins: {
+    legend: { display: false },
+    tooltip: {
+      callbacks: {
+        label: (context: { dataIndex: number; parsed: { x: number | null } }) =>
+          `${context.parsed.x ?? 0} / ${criteria.value[context.dataIndex]?.max ?? 100}`,
+      },
+    },
+  },
+  scales: { x: { min: 0, max: Math.max(...criteria.value.map((item) => item.max), 10) } },
+}))
+
+// ---------- 词云（chart.js 的 wordCloud 插件，canvas 上画，要自己管实例） ----------
+
+const WORD_COLORS = ["#2080f0", "#18a058", "#d03050", "#f0a020", "#7a3e9d", "#13c2c2"]
+const cloudCanvas = useTemplateRef<HTMLCanvasElement>("cloudCanvas")
+let cloud: ChartJS | null = null
+
+function drawCloud() {
+  cloud?.destroy()
+  cloud = null
+  const words = props.data.wordFrequencies
+  if (!cloudCanvas.value || !words.length) return
+  const max = Math.max(...words.map((word) => word.count))
+  cloud = new ChartJS(cloudCanvas.value, {
+    type: "wordCloud" as never,
+    data: {
+      labels: words.map((word) => word.word),
+      datasets: [
+        {
+          label: "",
+          data: words.map((word) => 12 + (word.count / max) * 42),
+          color: words.map((_, i) => WORD_COLORS[i % WORD_COLORS.length]),
+          rotate: 0,
+        } as never,
+      ],
+    },
+    options: {
+      responsive: true,
+      maintainAspectRatio: false,
+      plugins: {
+        legend: { display: false },
+        tooltip: {
+          callbacks: {
+            label: (context: { dataIndex: number }) => {
+              const word = words[context.dataIndex]
+              return word ? `${word.word}：${word.count} 次` : ""
+            },
+          },
+        },
+      },
+    } as never,
+  })
+}
+
+watch(
+  () => [props.data.wordFrequencies, chartKey.value],
+  () => nextTick(drawCloud),
+  { immediate: true },
+)
+onUnmounted(() => cloud?.destroy())
+
+// ---------- 每人最好的一次：没交的在前，其次按分数从低到高 ----------
+
+const people = computed(() => [
+  ...props.data.dataUnaccepted.map((row) => ({
+    username: row.username,
+    name: row.realName,
+    grade: null as string | null,
+    score: null as number | null,
+    count: 0,
+  })),
+  ...props.data.people.map((row) => ({
+    username: row.username,
+    name: row.realName,
+    grade: row.bestGrade,
+    score: row.bestScore,
+    count: row.count,
+  })),
+])
+
+function gradeStyle(grade: string | null) {
+  const map: Record<string, ReturnType<typeof tone>> = {
+    S: tone("success"),
+    A: tone("info"),
+    B: tone("warning"),
+    C: tone("error"),
+  }
+  const t = grade ? map[grade] : null
+  return t
+    ? { color: t.color, background: t.background }
+    : { color: theme.value.textColor3, background: theme.value.actionColor }
+}
+</script>
+
+<template>
+  <div class="flow-stats">
+    <div class="summary">
+      <StatItem label="提交" :value="data.totalCount" unit="张" />
+      <StatItem label="平均分" :value="data.avgScore" />
+      <StatItem
+        label="拿到 A / S"
+        :value="`${goodCount} / ${personCount}`"
+        unit="人"
+        tone="success"
+      />
+      <StatItem
+        label="一张没交"
+        :value="data.dataUnaccepted.length"
+        unit="人"
+        tone="error"
+        :hidden="!data.personCount"
+      />
+      <span class="spacer"></span>
+      <!-- 没选班级就没有花名册，「班级完成度」无从谈起 -->
+      <span v-if="data.personCount" class="ring-wrap">
+        <RingChart
+          :value="goodCount"
+          :total="personCount"
+          :color="tone('info').solid"
+          :labels="['拿到 A / S', '还没有']"
+        />
+        <span class="ring-label">班级<br />完成度</span>
+      </span>
+    </div>
+
+    <div v-if="!data.totalCount && !data.dataUnaccepted.length" class="empty">
+      这段时间没有人交流程图
+    </div>
+    <div v-else class="body">
+      <div class="row-cards">
+        <div class="card grade">
+          <div class="card-title">等级分布</div>
+          <div class="chart">
+            <Doughnut :key="chartKey" :data="gradeData" :options="gradeOptions" />
+          </div>
+        </div>
+        <div v-if="criteria.length" class="card radar">
+          <div class="card-title">四项评分（平均得分率）</div>
+          <div class="chart">
+            <Radar :key="chartKey" :data="radarData" :options="radarOptions" />
+          </div>
+        </div>
+        <div v-if="criteria.length" class="card grow">
+          <div class="card-title">各项平均分</div>
+          <div class="chart"><Bar :key="chartKey" :data="barData" :options="barOptions" /></div>
+        </div>
+      </div>
+      <div class="row-cards bottom">
+        <div class="card grow">
+          <div class="card-title">常见问题高频词（最近的评语里）</div>
+          <div class="cloud"><canvas ref="cloudCanvas"></canvas></div>
+          <div v-if="!data.wordFrequencies.length" class="muted">评语太少，还拼不出词云</div>
+        </div>
+        <div class="card people">
+          <div class="card-title">每人最好的一次（没交的在前）</div>
+          <div class="people-list">
+            <div v-for="row in people" :key="row.username" class="person">
+              <b class="p-name" :title="row.username">{{ row.name }}</b>
+              <span class="grade-pill" :style="gradeStyle(row.grade)">
+                {{ row.grade ? `${row.grade} 级 ${row.score ?? 0} 分` : "没交" }}
+              </span>
+              <span class="muted">{{ row.count }} 次</span>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.flow-stats {
+  flex: 1 1 0;
+  min-height: 0;
+  display: flex;
+  flex-direction: column;
+}
+
+.summary {
+  height: 72px;
+  flex: none;
+  box-sizing: border-box;
+  padding: 0 20px;
+  display: flex;
+  align-items: center;
+  gap: 36px;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+  background: v-bind("theme.actionColor");
+}
+
+.spacer {
+  flex: 1 1 0;
+}
+
+.ring-wrap {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.ring-label {
+  font-size: 12px;
+  line-height: 1.5;
+  color: v-bind("theme.textColor3");
+}
+
+.body {
+  flex: 1 1 0;
+  min-height: 0;
+  overflow-y: auto;
+  box-sizing: border-box;
+  padding: 16px 20px;
+  display: flex;
+  flex-direction: column;
+  gap: 14px;
+}
+
+.row-cards {
+  display: flex;
+  gap: 14px;
+  height: 220px;
+  flex: none;
+}
+
+.row-cards.bottom {
+  height: 300px;
+}
+
+.card {
+  box-sizing: border-box;
+  border: 1px solid v-bind("theme.dividerColor");
+  border-radius: 8px;
+  background: v-bind("theme.cardColor");
+  padding: 12px 14px;
+  display: flex;
+  flex-direction: column;
+  gap: 10px;
+  min-width: 0;
+}
+
+.card.grade {
+  width: 340px;
+  flex: none;
+}
+
+.card.radar {
+  width: 300px;
+  flex: none;
+}
+
+.card.grow {
+  flex: 1 1 0;
+}
+
+.card.people {
+  width: 420px;
+  flex: none;
+}
+
+.card-title {
+  font-size: 13px;
+  font-weight: 600;
+  color: v-bind("theme.textColor2");
+}
+
+.chart,
+.cloud {
+  flex: 1 1 0;
+  min-height: 0;
+  position: relative;
+}
+
+.people-list {
+  flex: 1 1 0;
+  min-height: 0;
+  overflow-y: auto;
+}
+
+.person {
+  height: 34px;
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+  font-size: 13px;
+}
+
+.p-name {
+  width: 80px;
+  flex: none;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.grade-pill {
+  width: 100px;
+  flex: none;
+  height: 22px;
+  border-radius: 11px;
+  font-size: 12px;
+  font-weight: 700;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.muted {
+  color: v-bind("theme.textColor3");
+  font-size: 12px;
+}
+
+.empty {
+  padding: 60px 16px;
+  text-align: center;
+  color: v-bind("theme.textColor3");
+}
+</style>
diff --git a/apps/web/src/oj/statistics/components/RingChart.vue b/apps/web/src/oj/statistics/components/RingChart.vue
new file mode 100644
index 0000000..464f62a
--- /dev/null
+++ b/apps/web/src/oj/statistics/components/RingChart.vue
@@ -0,0 +1,77 @@
+<script setup lang="ts">
+import { ArcElement, Chart as ChartJS, Tooltip } from "chart.js"
+import { Doughnut } from "vue-chartjs"
+import { useChartTheme } from "shared/composables/chartTheme"
+
+ChartJS.register(ArcElement, Tooltip)
+
+/**
+ * 数字行右边的小圆环（提交正确率、班级完成度）。中间写百分比，
+ * 鼠标停上去看两段各是多少 —— 这是 chart.js 现成的提示。
+ */
+const props = defineProps<{
+  value: number
+  total: number
+  color: string
+  /** 两段的名字，提示里用：["正确", "没对"] */
+  labels: [string, string]
+  size?: number
+}>()
+
+const { chartKey, gridColor } = useChartTheme()
+
+const pct = computed(() => (props.total > 0 ? Math.round((props.value / props.total) * 100) : 0))
+
+const data = computed(() => ({
+  labels: props.labels,
+  datasets: [
+    {
+      data: [props.value, Math.max(0, props.total - props.value)],
+      backgroundColor: [props.color, gridColor.value],
+      borderWidth: 0,
+    },
+  ],
+}))
+
+const options = {
+  responsive: true,
+  maintainAspectRatio: false,
+  cutout: "72%",
+  animation: false as const,
+  plugins: {
+    legend: { display: false },
+    tooltip: {
+      callbacks: {
+        label: (context: { label: string; parsed: number }) =>
+          `${context.label}：${context.parsed}`,
+      },
+    },
+  },
+}
+</script>
+
+<template>
+  <span class="ring" :style="{ width: `${size ?? 48}px`, height: `${size ?? 48}px` }">
+    <Doughnut :key="chartKey" :data="data" :options="options" />
+    <span class="center">{{ total > 0 ? `${pct}%` : "—" }}</span>
+  </span>
+</template>
+
+<style scoped>
+.ring {
+  position: relative;
+  display: inline-block;
+  flex: none;
+}
+
+.center {
+  position: absolute;
+  inset: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 11px;
+  font-weight: 700;
+  pointer-events: none;
+}
+</style>
diff --git a/apps/web/src/oj/statistics/components/StatItem.vue b/apps/web/src/oj/statistics/components/StatItem.vue
new file mode 100644
index 0000000..1460847
--- /dev/null
+++ b/apps/web/src/oj/statistics/components/StatItem.vue
@@ -0,0 +1,54 @@
+<script setup lang="ts">
+import { useThemeVars } from "naive-ui"
+import { useTone, type Tone } from "oj/submission/composables/tone"
+
+/** 数字行的一格：小字标签 + 大号数字 + 单位 */
+const props = defineProps<{
+  label: string
+  value: string | number
+  unit?: string
+  tone?: Tone
+  /** 算不出来的（没选班级就没有花名册）整格不显示，免得写个 0 让人误会 */
+  hidden?: boolean
+}>()
+
+const theme = useThemeVars()
+const toneOf = useTone()
+const color = computed(() => (props.tone ? toneOf(props.tone).color : theme.value.textColor1))
+</script>
+
+<template>
+  <div v-if="!hidden" class="stat">
+    <span class="label">{{ label }}</span>
+    <span class="value-line">
+      <b class="value" :style="{ color }">{{ value }}</b>
+      <span v-if="unit" class="unit">{{ unit }}</span>
+    </span>
+  </div>
+</template>
+
+<style scoped>
+.stat {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  flex: none;
+}
+
+.label,
+.unit {
+  font-size: 12px;
+  color: v-bind("theme.textColor3");
+}
+
+.value-line {
+  display: flex;
+  align-items: baseline;
+  gap: 5px;
+}
+
+.value {
+  font-size: 22px;
+  font-variant-numeric: tabular-nums;
+}
+</style>
diff --git a/apps/web/src/oj/statistics/index.vue b/apps/web/src/oj/statistics/index.vue
new file mode 100644
index 0000000..097d9ab
--- /dev/null
+++ b/apps/web/src/oj/statistics/index.vue
@@ -0,0 +1,397 @@
+<script setup lang="ts">
+import { Icon } from "@iconify/vue"
+import { useThemeVars } from "naive-ui"
+import { useRouteQuery } from "@vueuse/router"
+import type {
+  FlowchartStatistics,
+  SubmissionStatistics,
+  SubmissionStatisticsGrid,
+} from "@oj2/contract"
+import {
+  getFlowchartStatistics,
+  getSubmissionStatistics,
+  getSubmissionStatisticsGrid,
+} from "oj/api"
+import { useConfigStore } from "shared/store/config"
+import { fromPickerValue, toPickerValue } from "utils/functions"
+import { useTone } from "oj/submission/composables/tone"
+import { classLabel } from "oj/submission/utils"
+import ByClass from "./components/ByClass.vue"
+import CodeStats from "./components/CodeStats.vue"
+import RingChart from "./components/RingChart.vue"
+import StatItem from "./components/StatItem.vue"
+import { DEFAULT_PERIOD, PERIOD_OPTIONS, periodRange, type Period } from "./period"
+
+/**
+ * 数据统计（设计稿「统计重设计 · 定稿 B」）。从提交列表、题目页的弹框改成独立页面。
+ *
+ * 分工：**课堂看板管这节课，这里管回头看**（用户定的）。所以这页不自动刷新、没有
+ * 投影用的大字名单和请假隐藏 —— 那些在看板上。课堂统计一般看一两节课，时间段默认「两节课」。
+ *
+ * 查询条件都在地址栏里：从提交列表、题目页带过来，刷新、转发给别的老师都还是这一份。
+ */
+const FlowStats = defineAsyncComponent(() => import("./components/FlowStats.vue"))
+
+const router = useRouter()
+const configStore = useConfigStore()
+const theme = useThemeVars()
+const tone = useTone()
+const message = useMessage()
+
+const tab = useRouteQuery<string>("tab", "code", { mode: "replace" })
+const className = useRouteQuery<string>("className", "", { mode: "replace" })
+const username = useRouteQuery<string>("username", "", { mode: "replace" })
+const problem = useRouteQuery<string>("problem", "", { mode: "replace" })
+const period = useRouteQuery<string>("period", DEFAULT_PERIOD, { mode: "replace" })
+const from = useRouteQuery<string>("from", "", { mode: "replace" })
+const to = useRouteQuery<string>("to", "", { mode: "replace" })
+
+const periodValue = computed<Period>(() =>
+  PERIOD_OPTIONS.some((option) => option.value === period.value)
+    ? (period.value as Period)
+    : DEFAULT_PERIOD,
+)
+
+const custom = computed<[number, number] | null>(() =>
+  from.value && to.value ? [Number(from.value), Number(to.value)] : null,
+)
+
+/** n-date-picker 按浏览器时区渲染，存取都要平移到东八区（见 utils/functions 的注释） */
+const pickerValue = computed<[number, number] | null>(() =>
+  custom.value ? [toPickerValue(custom.value[0]), toPickerValue(custom.value[1])] : null,
+)
+function pickDates(value: [number, number] | null) {
+  if (!value) {
+    from.value = ""
+    to.value = ""
+    return
+  }
+  from.value = String(fromPickerValue(value[0]))
+  to.value = String(fromPickerValue(value[1]))
+}
+
+/**
+ * 统计接口的「用户名」是 ilike：填 `ks253` 圈一个班。选了班级又填了学生时按学生查，
+ * 学生名字不带班级前缀的话补上，免得别的班重名的混进来
+ */
+const usernameParam = computed(() => {
+  const name = username.value.trim()
+  if (name) {
+    return className.value && !name.toLowerCase().startsWith("ks")
+      ? `ks${className.value}${name}`
+      : name
+  }
+  return className.value ? `ks${className.value}` : ""
+})
+
+/** 没选班级、没填学生：先按班级汇总（多半是从题目页进来的） */
+const byClass = computed(() => !usernameParam.value)
+
+const classOptions = computed(() => {
+  const list = configStore.config?.classList ?? []
+  const all = className.value && !list.includes(className.value) ? [className.value, ...list] : list
+  return all.map((item) => ({ label: classLabel(item), value: item }))
+})
+
+// ---------- 取数 ----------
+
+const loading = ref(false)
+const failed = ref(false)
+const stats = ref<SubmissionStatistics | null>(null)
+const grid = ref<SubmissionStatisticsGrid | null>(null)
+const flow = ref<FlowchartStatistics | null>(null)
+const rangeText = ref("")
+const withinToday = ref(false)
+let seq = 0
+
+async function load() {
+  const current = ++seq
+  const range = periodRange(periodValue.value, custom.value)
+  rangeText.value = range.text
+  withinToday.value = range.withinToday
+  const duration = { start: range.start, end: range.end }
+  loading.value = true
+  failed.value = false
+  try {
+    if (tab.value === "flow") {
+      const res = await getFlowchartStatistics(duration, problem.value, usernameParam.value)
+      if (current !== seq) return
+      flow.value = res
+    } else {
+      const [s, g] = await Promise.all([
+        getSubmissionStatistics(duration, problem.value, usernameParam.value),
+        getSubmissionStatisticsGrid(duration, problem.value, usernameParam.value),
+      ])
+      if (current !== seq) return
+      stats.value = s
+      grid.value = g
+    }
+  } catch (error) {
+    if (current !== seq) return
+    failed.value = true
+    // 题号打错是最常见的：后端 404 problem-not-found
+    const code = (error as { error?: string })?.error
+    if (code === "problem-not-found") message.warning("有题号找不到，检查一下是不是打错了")
+  } finally {
+    if (current === seq) loading.value = false
+  }
+}
+
+onMounted(load)
+watch([tab, className, periodValue, custom], load)
+watchDebounced([username, problem], load, { debounce: 600, maxWait: 1500 })
+
+// ---------- 数字行（代码） ----------
+
+const doneCount = computed(() => stats.value?.data.filter((row) => row.done).length ?? 0)
+/**
+ * 没填题号时后端的「做完」是「至少做对一道」—— 一个月里零零散散几十道题，谈不上
+ * 「全做完」。这时这一格叫「做对过题」，别和左边「全部 N 道 · 做完 0 人」打架
+ */
+const hasProblems = computed(() => !!problem.value.trim())
+const personCount = computed(() => stats.value?.personCount ?? 0)
+const judged = computed(() =>
+  stats.value ? stats.value.submissionCount - stats.value.judgingCount : 0,
+)
+
+// ---------- 两个入口 ----------
+
+/** 1366 以下（机房 1280 的屏）右上两个入口只留图标 */
+const narrow = useMediaQuery("(max-width: 1365px)")
+
+function openList() {
+  const href = router.resolve({
+    name: "submissions",
+    query: {
+      ...(tab.value === "flow" ? { language: "Flowchart" } : {}),
+      ...(className.value && !username.value ? { className: className.value } : {}),
+      ...(username.value ? { username: usernameParam.value } : {}),
+      ...(problem.value ? { problem: problem.value } : {}),
+      ...(withinToday.value ? { today: "1" } : {}),
+    },
+  }).href
+  window.open(href, "_blank")
+}
+
+function pickClass(value: string) {
+  className.value = value
+  username.value = ""
+}
+</script>
+
+<template>
+  <div class="page">
+    <div class="filters">
+      <span class="title">数据统计</span>
+      <n-radio-group v-model:value="tab" size="small">
+        <n-radio-button value="code">代码</n-radio-button>
+        <n-radio-button value="flow">流程图</n-radio-button>
+      </n-radio-group>
+      <span class="vsep"></span>
+      <n-select
+        :value="className || null"
+        class="w-class"
+        size="small"
+        :options="classOptions"
+        placeholder="全部班级"
+        clearable
+        filterable
+        @update:value="(v: string | null) => (className = v ?? '')"
+      />
+      <n-input v-model:value="username" class="w-user" size="small" clearable placeholder="学生">
+        <template #prefix><Icon icon="ph:magnifying-glass" /></template>
+      </n-input>
+      <n-input
+        v-model:value="problem"
+        class="w-problem"
+        size="small"
+        clearable
+        placeholder="题号，几道用空格隔开"
+      >
+        <template #prefix><Icon icon="ph:hash" /></template>
+      </n-input>
+      <n-select
+        :value="periodValue"
+        class="w-period"
+        size="small"
+        :options="PERIOD_OPTIONS.map((o) => ({ label: o.label, value: o.value }))"
+        :consistent-menu-width="false"
+        @update:value="(v: string) => (period = v)"
+      />
+      <n-date-picker
+        v-if="periodValue === 'custom'"
+        :value="pickerValue"
+        type="daterange"
+        size="small"
+        class="w-dates"
+        clearable
+        @update:value="pickDates"
+      />
+      <span v-else class="range">{{ rangeText }}</span>
+      <n-spin v-if="loading" :size="14" />
+      <n-text v-if="failed" type="error" class="range">没拉下来，改一下条件再试</n-text>
+      <span class="spacer"></span>
+      <n-button
+        size="small"
+        quaternary
+        title="这节课去课堂看板"
+        aria-label="这节课去课堂看板"
+        @click="router.push('/classroom')"
+      >
+        <template #icon><Icon icon="ph:monitor" /></template>
+        <template v-if="!narrow">这节课去课堂看板</template>
+      </n-button>
+      <n-button size="small" title="在提交列表里看" aria-label="在提交列表里看" @click="openList">
+        <template #icon><Icon icon="ph:arrow-square-out" /></template>
+        <template v-if="!narrow">在提交列表里看</template>
+      </n-button>
+    </div>
+
+    <template v-if="tab === 'flow'">
+      <FlowStats v-if="flow" :data="flow" />
+    </template>
+
+    <template v-else-if="stats && grid">
+      <div class="summary">
+        <StatItem label="提交" :value="stats.submissionCount" unit="条" />
+        <StatItem
+          label="正确率"
+          :value="`${Math.round(stats.correctRate)}%`"
+          :unit="stats.judgingCount ? `判题中 ${stats.judgingCount}` : ''"
+        />
+        <template v-if="personCount">
+          <StatItem
+            :label="hasProblems ? '做完' : '做对过题'"
+            :value="`${doneCount} / ${personCount}`"
+            unit="人"
+            tone="success"
+          />
+          <StatItem
+            v-if="hasProblems"
+            label="完成度"
+            :value="`${personCount ? Math.round((doneCount / personCount) * 100) : 0}%`"
+          />
+          <StatItem label="一道没交" :value="stats.dataUnaccepted.length" unit="人" tone="error" />
+        </template>
+        <StatItem
+          :label="hasProblems ? '交了没全对' : '一道没做对'"
+          :value="stats.dataAttempted.length"
+          unit="人"
+          tone="warning"
+        />
+        <span class="spacer"></span>
+        <span class="ring-wrap">
+          <RingChart
+            :value="stats.acceptedCount"
+            :total="judged"
+            :color="tone('success').solid"
+            :labels="['正确', '没对']"
+          />
+          <span class="ring-label">提交<br />正确率</span>
+        </span>
+        <span v-if="personCount && hasProblems" class="ring-wrap">
+          <RingChart
+            :value="doneCount"
+            :total="personCount"
+            :color="tone('info').solid"
+            :labels="['做完', '没做完']"
+          />
+          <span class="ring-label">班级<br />完成度</span>
+        </span>
+      </div>
+      <ByClass v-if="byClass" :grid="grid" @pick="pickClass" />
+      <CodeStats v-else :stats="stats" :grid="grid" />
+    </template>
+  </div>
+</template>
+
+<style scoped>
+/* 铺满顶栏以下，和提交列表同一个做法（负边距吃掉外层 16px） */
+.page {
+  margin: -16px;
+  height: calc(100vh - 56px);
+  display: flex;
+  flex-direction: column;
+  background: v-bind("theme.cardColor");
+}
+
+.filters {
+  height: 52px;
+  flex: none;
+  box-sizing: border-box;
+  padding: 0 20px;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  white-space: nowrap;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+}
+
+.title {
+  font-size: 17px;
+  font-weight: 700;
+  margin-right: 6px;
+}
+
+.vsep {
+  width: 1px;
+  height: 20px;
+  margin: 0 4px;
+  background: v-bind("theme.dividerColor");
+}
+
+.w-class {
+  width: 132px;
+}
+.w-user {
+  width: 110px;
+}
+.w-problem {
+  width: 220px;
+}
+.w-period {
+  width: 150px;
+}
+.w-dates {
+  width: 240px;
+}
+
+@media (max-width: 1365px) {
+  .w-problem {
+    width: 190px;
+  }
+}
+
+.range {
+  font-size: 12px;
+  color: v-bind("theme.textColor3");
+}
+
+.spacer {
+  flex: 1 1 0;
+}
+
+.summary {
+  height: 72px;
+  flex: none;
+  box-sizing: border-box;
+  padding: 0 20px;
+  display: flex;
+  align-items: center;
+  gap: 36px;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+  background: v-bind("theme.actionColor");
+}
+
+.ring-wrap {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.ring-label {
+  font-size: 12px;
+  line-height: 1.5;
+  color: v-bind("theme.textColor3");
+}
+</style>
diff --git a/apps/web/src/oj/statistics/period.ts b/apps/web/src/oj/statistics/period.ts
new file mode 100644
index 0000000..e1e7964
--- /dev/null
+++ b/apps/web/src/oj/statistics/period.ts
@@ -0,0 +1,101 @@
+import { TIME_ZONE_OFFSET_MINUTES } from "@oj2/contract"
+import { parseTime, zonedParts } from "utils/functions"
+
+const OFFSET_MS = TIME_ZONE_OFFSET_MINUTES * 60_000
+const HOUR = 3_600_000
+const DAY = 86_400_000
+
+/**
+ * 统计页的时间段。课堂统计一般看一两节课（用户原话），所以这两档在最前面、
+ * 默认「两节课」；后面几档是回头看。原来弹框里的 10 / 20 / 30 分钟是上课盯人用的，
+ * 那件事现在归课堂看板。
+ */
+export const PERIOD_OPTIONS = [
+  { label: "这节课（1 小时内）", value: "1h" },
+  { label: "两节课（2 小时内）", value: "2h" },
+  { label: "今天", value: "today" },
+  { label: "最近 7 天", value: "7d" },
+  { label: "最近 30 天", value: "30d" },
+  { label: "这学期", value: "term" },
+  { label: "全部", value: "all" },
+  { label: "自己选日子", value: "custom" },
+] as const
+
+export type Period = (typeof PERIOD_OPTIONS)[number]["value"]
+export const DEFAULT_PERIOD: Period = "2h"
+
+/** 东八区某天 0 点对应的 UTC 时刻 */
+function dayStartOf(year: number, month: number, day: number) {
+  return Date.UTC(year, month - 1, day) - OFFSET_MS
+}
+
+/** 东八区「现在」这一天的 0 点 */
+function todayStart(now: number) {
+  const p = zonedParts(new Date(now))!
+  return dayStartOf(p.year, p.month, p.day)
+}
+
+/** 这学期从哪天起：9 月到次年 2 月算秋季学期（9 月 1 日起），3 到 8 月算春季（3 月 1 日起） */
+function termStart(now: number) {
+  const p = zonedParts(new Date(now))!
+  if (p.month >= 9) return dayStartOf(p.year, 9, 1)
+  if (p.month >= 3) return dayStartOf(p.year, 3, 1)
+  return dayStartOf(p.year - 1, 9, 1)
+}
+
+/**
+ * 时间段换成接口要的 start / end（ISO），外加一句给人看的范围。
+ * `custom` 用的是 [开始日 0 点, 结束日 24 点)，两个都是 date picker 取回来的 UTC 时刻。
+ */
+export function periodRange(period: Period, custom: [number, number] | null, now = Date.now()) {
+  let start: number | null
+  let end = now
+  switch (period) {
+    case "1h":
+      start = now - HOUR
+      break
+    case "2h":
+      start = now - 2 * HOUR
+      break
+    case "today":
+      start = todayStart(now)
+      break
+    case "7d":
+      start = todayStart(now) - 6 * DAY
+      break
+    case "30d":
+      start = todayStart(now) - 29 * DAY
+      break
+    case "term":
+      start = termStart(now)
+      break
+    case "custom":
+      if (custom) {
+        start = custom[0]
+        end = custom[1] + DAY
+      } else {
+        start = todayStart(now)
+      }
+      break
+    default:
+      start = null
+  }
+  const text = describe(start, end, period)
+  return {
+    start: start === null ? undefined : new Date(start).toISOString(),
+    end: new Date(end).toISOString(),
+    text,
+    /** 范围落在今天以内：提交列表那边能用「今天」接上 */
+    withinToday: start !== null && start >= todayStart(now),
+  }
+}
+
+function describe(start: number | null, end: number, period: Period) {
+  if (start === null) return ""
+  if (period === "1h" || period === "2h") {
+    return `${parseTime(new Date(start), "HH:mm")}–${parseTime(new Date(end), "HH:mm")}`
+  }
+  const from = parseTime(new Date(start), "M月D日")
+  const to = parseTime(new Date(end - 1), "M月D日")
+  return from === to ? from : `${from}–${to}`
+}
diff --git a/apps/web/src/oj/submission/list.vue b/apps/web/src/oj/submission/list.vue
index 7bf9f03..250c6ae 100644
--- a/apps/web/src/oj/submission/list.vue
+++ b/apps/web/src/oj/submission/list.vue
@@ -44,10 +44,6 @@ import { classLabel, submissionClockText, submissionDayText } from "./utils"
 // （光 chart.js 就 197KB）
 const SubmissionPane = defineAsyncComponent(() => import("./components/SubmissionPane.vue"))
 const FlowchartPane = defineAsyncComponent(() => import("./components/FlowchartPane.vue"))
-const StatisticsPanel = defineAsyncComponent(() => import("shared/components/StatisticsPanel.vue"))
-const FlowchartStatisticsPanel = defineAsyncComponent(
-  () => import("shared/components/FlowchartStatisticsPanel.vue"),
-)
 const TodayStatistics = defineAsyncComponent(() => import("./components/TodayStatistics.vue"))
 
 interface SubmissionQuery {
@@ -272,11 +268,10 @@ function move(step: 1 | -1) {
   query.page = page
 }
 
-const [statisticPanel, toggleStatisticPanel] = useToggle(false)
 const [todayPanel, toggleTodayPanel] = useToggle(false)
 
 onKeyStroke(["ArrowUp", "ArrowDown"], (e: KeyboardEvent) => {
-  if (!isDesktop.value || statisticPanel.value || todayPanel.value) return
+  if (!isDesktop.value || todayPanel.value) return
   // 焦点在输入框、下拉框里时不抢方向键
   const target = e.target as HTMLElement | null
   if (
@@ -504,6 +499,24 @@ function filterUser(username: string) {
   query.username = username
 }
 
+/**
+ * 「数据统计」：新标签打开统计页，带上现在的班级 / 学生 / 题号 / 代码或流程图
+ * （原来是这一页上的弹框）。「今天」带过去就是统计页的「今天」
+ */
+function openStatistics() {
+  const href = router.resolve({
+    name: "statistics",
+    query: {
+      ...(flowMode.value ? { tab: "flow" } : {}),
+      ...(query.className ? { className: query.className } : {}),
+      ...(query.username ? { username: query.username } : {}),
+      ...(query.problem ? { problem: query.problem } : {}),
+      ...(query.today === "1" ? { period: "today" } : {}),
+    },
+  }).href
+  window.open(href, "_blank")
+}
+
 function filterProblem(displayId: string) {
   query.problem = displayId
 }
@@ -692,11 +705,7 @@ function dayBreak(index: number) {
         <template v-if="!(teacher && narrowBar)">今日统计</template>
         <span v-if="todayCount" class="count">{{ todayCount }}</span>
       </n-button>
-      <n-button
-        v-if="teacher && route.name === 'submissions'"
-        size="small"
-        @click="toggleStatisticPanel(true)"
-      >
+      <n-button v-if="teacher && route.name === 'submissions'" size="small" @click="openStatistics">
         <template #icon><Icon icon="ph:chart-pie-slice" /></template>
         数据统计
       </n-button>
@@ -929,25 +938,6 @@ function dayBreak(index: number) {
     </n-drawer-content>
   </n-drawer>
 
-  <n-modal
-    v-if="teacher"
-    v-model:show="statisticPanel"
-    preset="card"
-    :style="{ maxWidth: isDesktop && '800px', maxHeight: '80vh' }"
-    :content-style="{ overflow: 'auto' }"
-    :title="flowMode ? '流程图提交的统计' : '提交记录的统计'"
-  >
-    <FlowchartStatisticsPanel
-      v-if="flowMode"
-      :problem="query.problem"
-      :username="query.className ? 'ks' + query.className : query.username"
-    />
-    <StatisticsPanel
-      v-else
-      :problem="query.problem"
-      :username="query.className ? 'ks' + query.className : query.username"
-    />
-  </n-modal>
   <n-modal
     v-model:show="todayPanel"
     preset="card"
diff --git a/apps/web/src/routes.ts b/apps/web/src/routes.ts
index 7818621..a5fb8bc 100644
--- a/apps/web/src/routes.ts
+++ b/apps/web/src/routes.ts
@@ -75,6 +75,12 @@ export const ojs: RouteRecordRaw = {
       component: () => import("oj/classroom/board.vue"),
       meta: { requiresAuth: true, requiresTeacherAdmin: true },
     },
+    {
+      path: "statistics",
+      name: "statistics",
+      component: () => import("oj/statistics/index.vue"),
+      meta: { requiresAuth: true, requiresTeacherAdmin: true },
+    },
     {
       path: "class",
       name: "class",
diff --git a/apps/web/src/utils/constants.ts b/apps/web/src/utils/constants.ts
index 79fcb44..5ae8314 100644
--- a/apps/web/src/utils/constants.ts
+++ b/apps/web/src/utils/constants.ts
@@ -156,8 +156,6 @@ export const STORAGE_KEY = {
   ADMIN_SIDER_COLLAPSED: "adminSiderCollapsed",
   DEMO_MODE: "demoMode",
   LOGIN_CLASS: "loginClass",
-  STATISTICS_QUERY: "statisticsQuery",
-  FLOWCHART_STATISTICS_QUERY: "flowchartStatisticsQuery",
 }
 
 export const DIFFICULTY = {
@@ -328,23 +326,6 @@ export const DURATION_OPTIONS = [
   { label: "一年内", value: "years:1" },
 ] as const
 
-/**
- * 两个统计面板（提交统计、流程图统计）的时段下拉。
- *
- * 比通用的那份多了头尾：前面三档分钟级是给**上课当场**用的 —— 老师布置完一道题，
- * 想看的就是「刚才这十分钟谁交了」；末尾的 `all` 不是一个时长，`query.duration === "all"`
- * 会走各自的分支不带时间条件，所以它永远不会进 durationFromValue()。
- *
- * 原来这份列表在两个面板里逐字抄了两遍。
- */
-export const PANEL_DURATION_OPTIONS = [
-  { label: "10分钟内", value: "minutes:10" },
-  { label: "20分钟内", value: "minutes:20" },
-  { label: "30分钟内", value: "minutes:30" },
-  ...DURATION_OPTIONS,
-  { label: "全部时段", value: "all" },
-] as const
-
 /**
  * 榜单和班级对比用的长时段，一周起步。
  *