diff --git a/apps/api/src/routes/ai.ts b/apps/api/src/routes/ai.ts
index 1bf46d9..1633d91 100644
--- a/apps/api/src/routes/ai.ts
+++ b/apps/api/src/routes/ai.ts
@@ -23,6 +23,7 @@ import { generateFilteredHint } from "../services/hint-filter"
 import { buildDetail, buildDuration, listSolved } from "../services/learning-stats"
 import { decideHintLevel } from "../services/hint-level"
 import { hintDiagnosis, hintPrompt, referenceAnswer } from "../services/hint-diagnosis"
+import { classDetail } from "../services/ranking"
 import { consumeToken } from "../services/throttling"
 import { calendarDay, dayNumber, dayText, localTime, localWeekday } from "../time"
 import { countFailedSubmissions, isTeacherOrAbove, asRecord, queryInteger } from "./helpers"
@@ -358,9 +359,18 @@ aiRoutes.post("/ai/class-analysis", requireAuth, async (c) => {
   if (!parsed.success) return parsed.response
   const limited = await throttleAi(c)
   if (limited) return limited
+  // 数字和抽屉里看到的是同一份（services/ranking.ts 的 classDetail），不再由前端整包传上来
+  const detail = await classDetail(parsed.data.className, true)
+  if (!detail.members) return failure(c, 404, "class-not-found", "这个班没有学生")
   return streamChat(
-    "你是编程教育数据分析专家。根据班级 OJ 数据，从整体水平、参与积极性、均衡性、梯队和改进建议五方面输出中文 Markdown 报告。",
-    JSON.stringify(parsed.data.comparison),
+    [
+      "你是编程课老师的助教。下面是一个班这学期在 OJ 上的做题数据（JSON，人名是用户名）。",
+      "用中文 Markdown 写一份给老师看的简短分析，分四段，每段一两句，段首加粗：",
+      "**整体**（人均和年级比、班级对抗第几）、**节奏**（每周人均的起伏，课上做还是课外也练）、",
+      "**分化**（前后 10%、人最多的那一档同分）、**建议**（点名 care 里的同学，给下节课能直接做的事）。",
+      "用大白话，不要出现四分位数、标准差、方差这类统计词，不要编数据里没有的数字。",
+    ].join(""),
+    JSON.stringify(detail),
   )
 })
 
diff --git a/apps/api/src/routes/ranking.ts b/apps/api/src/routes/ranking.ts
index 4e5ff3c..7793dba 100644
--- a/apps/api/src/routes/ranking.ts
+++ b/apps/api/src/routes/ranking.ts
@@ -3,7 +3,6 @@ import {
   rankPeriodSchema,
   rankScopeSchema,
   STUDENT_ROLES,
-  type ClassBattleItem,
   type RankBoard,
   type RankPeriod,
   type RankRow,
@@ -11,28 +10,24 @@ import {
   type SampleUser,
   type WeeklyChampion,
 } from "@oj2/contract"
-import {
-  and,
-  countDistinct,
-  desc,
-  eq,
-  gte,
-  inArray,
-  isNotNull,
-  isNull,
-  like,
-  min,
-  ne,
-  type SQL,
-} from "drizzle-orm"
+import { and, countDistinct, desc, eq, gte, inArray, isNotNull, ne } from "drizzle-orm"
 import { Hono } from "hono"
 
 import { optionalAuth, requireTeacher, type AppEnv } from "../auth/middleware"
 import { db, schema } from "../db"
 import { failure, parseBody, success } from "../http"
-import { JudgeStatus } from "../judge/status"
 import { dayStart, termStart, weekStart } from "../time"
-import { isTeacherOrAbove, rounded, sampleUser } from "./helpers"
+import {
+  audienceWhere,
+  classBattle,
+  classDetail,
+  loadEntrants,
+  rankedStudents,
+  standings,
+  WEEK_MS,
+  type Standing,
+} from "../services/ranking"
+import { isTeacherOrAbove, sampleUser } from "./helpers"
 
 /**
  * 排名页（设计稿「排名重设计」G1–G3）。口径见契约 `ranking.ts` 的注释：
@@ -40,12 +35,9 @@ import { isTeacherOrAbove, rounded, sampleUser } from "./helpers"
  */
 export const rankingRoutes = new Hono<AppEnv>()
 
-/** AST_CHECK_FAILED 也是答案对了，与周榜、课堂条同口径 */
-const SOLVED_RESULTS = [JudgeStatus.ACCEPTED, JudgeStatus.AST_CHECK_FAILED]
-
 /** 本年级 / 全服的榜面：前面这么多人 + 我附近一段，中间折起来 */
 const BOARD_HEAD = 16
-/** 我附近一段：前面 5 个、后面 7 个（前面的人是要追的，多给后面几个看「谁在追我」） */
+/** 我附近一段：前面 5 个、后面 7 个（多给后面几个：看得到后面的人离自己多近） */
 const WINDOW_BEFORE = 5
 const WINDOW_AFTER = 7
 /** 没有「我」（老师、没上榜）时榜面给多少 */
@@ -55,130 +47,6 @@ const TREND_WEEKS = 4
 /** 每周冠军列几周 */
 const CHAMPION_WEEKS = 3
 
-const WEEK_MS = 7 * 86_400_000
-
-/** 入榜人群：正常状态的学生与学生管理员，老师设成不计入排名的不算 */
-const rankedStudents = and(
-  inArray(schema.user.adminType, [...STUDENT_ROLES]),
-  eq(schema.user.isDisabled, false),
-  isNull(schema.user.rankHiddenAt),
-)!
-
-interface Entrant {
-  id: number
-  username: string
-  className: string | null
-  avatar: string | null
-  /** 每道题第一次做对的时刻，升序；毫秒数用来比较，原文留着给出参 */
-  times: number[]
-  stamps: string[]
-}
-
-interface Standing {
-  entrant: Entrant
-  rank: number
-  solved: number
-  reachedAt: string | null
-}
-
-function audienceWhere(scope: RankScope, className: string | null) {
-  if (scope === "class") return and(rankedStudents, eq(schema.user.className, className!))!
-  if (scope === "grade") return and(rankedStudents, like(schema.user.className, `${className}%`))!
-  return rankedStudents
-}
-
-function avatarOf(avatar: string | null) {
-  return !avatar || avatar.endsWith("/default.png") ? null : avatar
-}
-
-/**
- * 这群人、从 `since` 起每道题第一次做对的时刻。
- *
- * 先按 (人, 题) 取全部历史里的最早一次，再用 having 卡 `>= since` —— 这样「这学期」数的是
- * 这学期**第一次**做对的题，以前做对过的老题这学期重交一遍不算。比赛里的提交不算。
- * 走 `submission_public_metrics_idx`（user_id, problem_id, result, create_time，WHERE
- * contest_id IS NULL），全服全部历史实测 24ms。
- */
-async function loadEntrants(where: SQL, since: string | null): Promise<Entrant[]> {
-  const firstSolved = min(schema.submission.createTime)
-  const [people, solves] = await Promise.all([
-    db
-      .select({
-        id: schema.user.id,
-        username: schema.user.username,
-        className: schema.user.className,
-        avatar: schema.userProfile.avatar,
-      })
-      .from(schema.user)
-      .leftJoin(schema.userProfile, eq(schema.userProfile.userId, schema.user.id))
-      .where(where),
-    db
-      .select({ userId: schema.submission.userId, at: firstSolved })
-      .from(schema.submission)
-      .innerJoin(schema.user, eq(schema.user.id, schema.submission.userId))
-      .where(
-        and(
-          where,
-          isNull(schema.submission.contestId),
-          inArray(schema.submission.result, SOLVED_RESULTS),
-        ),
-      )
-      .groupBy(schema.submission.userId, schema.submission.problemId)
-      .having(since ? gte(firstSolved, since) : undefined),
-  ])
-
-  const byUser = new Map<number, string[]>()
-  for (const row of solves) {
-    if (!row.at) continue
-    const list = byUser.get(row.userId)
-    if (list) list.push(row.at)
-    else byUser.set(row.userId, [row.at])
-  }
-  return people.map((person) => {
-    const pairs = (byUser.get(person.id) ?? [])
-      .map((stamp) => [Date.parse(stamp), stamp] as const)
-      .sort((a, b) => a[0] - b[0])
-    return {
-      id: person.id,
-      username: person.username,
-      className: person.className,
-      avatar: avatarOf(person.avatar),
-      times: pairs.map(([time]) => time),
-      stamps: pairs.map(([, stamp]) => stamp),
-    }
-  })
-}
-
-/**
- * `cutoff` 那一刻的名次（不给就是现在）。一样多的先做到的在前，再一样按 id ——
- * 第三档不是凑数：同一秒做到的确实有（一节课的最后一道），没有稳定的兜底键名次会跳。
- * `includeZero`：本班把一道没做对的也排上（全班名单），本年级 / 全服不排。
- */
-function standings(entrants: Entrant[], cutoff: number | null, includeZero: boolean) {
-  const list = entrants
-    .map((entrant) => {
-      let solved = entrant.times.length
-      if (cutoff !== null) {
-        solved = 0
-        while (solved < entrant.times.length && entrant.times[solved]! < cutoff) solved++
-      }
-      return {
-        entrant,
-        solved,
-        reached: solved ? entrant.times[solved - 1]! : Number.POSITIVE_INFINITY,
-        reachedAt: solved ? entrant.stamps[solved - 1]! : null,
-      }
-    })
-    .filter((row) => includeZero || row.solved > 0)
-    .sort((a, b) => b.solved - a.solved || a.reached - b.reached || a.entrant.id - b.entrant.id)
-  return list.map((row, index): Standing => ({
-    entrant: row.entrant,
-    rank: index + 1,
-    solved: row.solved,
-    reachedAt: row.reachedAt,
-  }))
-}
-
 function toRow(standing: Standing, change: number | null): RankRow {
   const { entrant } = standing
   return {
@@ -311,7 +179,7 @@ rankingRoutes.get("/rankings/board", optionalAuth, async (c) => {
         )
       : null
 
-  // 一道没做对就不算上榜（本班的全班名单里也列着他，但没有名次可说，也没有对手）
+  // 一道没做对就不算上榜（本班的全班名单里也列着他，但没有名次可说，也没有前后一名）
   const meIndex = user ? now.findIndex((row) => row.entrant.id === user.id && row.solved > 0) : -1
   const me = meIndex >= 0 ? now[meIndex] : undefined
 
@@ -369,42 +237,19 @@ rankingRoutes.get("/rankings/board", optionalAuth, async (c) => {
 })
 
 /**
- * 班级对抗：全服每个班这学期人均做对几道，外加这周人均涨了多少。人均而不是总数 ——
- * 班级人数从 11 到 58 都有，比总数等于比人多。这学期一道没做对的班不列（还没开始用）。
- * 不计入排名的人分子分母都不算：抄来的题不该替全班加分。
+ * 班级对抗：全服每个班这学期人均做对几道，外加这周人均涨了多少（口径见 services/ranking.ts
+ * 的 classBattle）
  */
 rankingRoutes.get("/rankings/classes", async (c) => {
-  const where = and(
-    rankedStudents,
-    isNotNull(schema.user.className),
-    ne(schema.user.className, ""),
-  )!
-  const term = termStart()
-  const week = Date.parse(weekStart())
-  const entrants = await loadEntrants(where, term)
+  const { items } = await classBattle()
+  return success(c, items)
+})
 
-  const classes = new Map<string, { members: number; term: number; week: number }>()
-  for (const entrant of entrants) {
-    const entry = classes.get(entrant.className!) ?? { members: 0, term: 0, week: 0 }
-    entry.members++
-    entry.term += entrant.times.length
-    entry.week += entrant.times.filter((time) => time >= week).length
-    classes.set(entrant.className!, entry)
-  }
-
-  const result = [...classes]
-    .filter(([, entry]) => entry.term > 0)
-    .map(([className, entry]) => ({
-      className,
-      members: entry.members,
-      perCapita: rounded(entry.term / entry.members, 1),
-      weekGain: rounded(entry.week / entry.members, 1),
-    }))
-    .sort((a, b) => b.perCapita - a.perCapita || b.weekGain - a.weekGain)
-  return success(
-    c,
-    result.map((item, index) => ({ ...item, rank: index + 1 }) satisfies ClassBattleItem),
-  )
+/** 班级详情：谁都能看（原来的弹框就是），「要多关心的同学」只给老师 */
+rankingRoutes.get("/rankings/class-detail", optionalAuth, async (c) => {
+  const className = c.req.query("className")?.trim()
+  if (!className) return failure(c, 400, "class-missing", "没有班级")
+  return success(c, await classDetail(className, isTeacherOrAbove(c.get("user"))))
 })
 
 /** 本班每周冠军：最近几个已经结束的周，每周新做对最多的那个人（一样多先做到的） */
diff --git a/apps/api/src/services/ranking.ts b/apps/api/src/services/ranking.ts
new file mode 100644
index 0000000..d50db14
--- /dev/null
+++ b/apps/api/src/services/ranking.ts
@@ -0,0 +1,310 @@
+import {
+  STUDENT_ROLES,
+  type ClassBattleItem,
+  type ClassDetail,
+  type RankScope,
+} from "@oj2/contract"
+import {
+  and,
+  count,
+  eq,
+  gte,
+  inArray,
+  isNotNull,
+  isNull,
+  like,
+  min,
+  ne,
+  type SQL,
+} from "drizzle-orm"
+
+import { db, schema } from "../db"
+import { JudgeStatus } from "../judge/status"
+import { sampleUser, rounded } from "../routes/helpers"
+import { termStart, weekStart } from "../time"
+
+/**
+ * 排名页和班级详情、班级 AI 分析共用的口径（routes/ranking.ts、routes/ai.ts）：
+ * 「做对」= 这道题第一次做对落在这段时间里，比赛里的提交不算；入榜人群是正常状态的学生，
+ * 老师设成不计入排名的不算。
+ */
+
+/** AST_CHECK_FAILED 也是答案对了，与周榜、课堂条同口径 */
+export const SOLVED_RESULTS = [JudgeStatus.ACCEPTED, JudgeStatus.AST_CHECK_FAILED]
+
+export const WEEK_MS = 7 * 86_400_000
+
+/** 入榜人群：正常状态的学生与学生管理员，老师设成不计入排名的不算 */
+export const rankedStudents = and(
+  inArray(schema.user.adminType, [...STUDENT_ROLES]),
+  eq(schema.user.isDisabled, false),
+  isNull(schema.user.rankHiddenAt),
+)!
+
+export interface Entrant {
+  id: number
+  username: string
+  className: string | null
+  avatar: string | null
+  /** 每道题第一次做对的时刻，升序；毫秒数用来比较，原文留着给出参 */
+  times: number[]
+  stamps: string[]
+}
+
+export interface Standing {
+  entrant: Entrant
+  rank: number
+  solved: number
+  reachedAt: string | null
+}
+
+export function audienceWhere(scope: RankScope, className: string | null) {
+  if (scope === "class") return and(rankedStudents, eq(schema.user.className, className!))!
+  if (scope === "grade") return and(rankedStudents, like(schema.user.className, `${className}%`))!
+  return rankedStudents
+}
+
+export function avatarOf(avatar: string | null) {
+  return !avatar || avatar.endsWith("/default.png") ? null : avatar
+}
+
+/**
+ * 这群人、从 `since` 起每道题第一次做对的时刻。
+ *
+ * 先按 (人, 题) 取全部历史里的最早一次，再用 having 卡 `>= since` —— 这样「这学期」数的是
+ * 这学期**第一次**做对的题，以前做对过的老题这学期重交一遍不算。比赛里的提交不算。
+ * 走 `submission_public_metrics_idx`（user_id, problem_id, result, create_time，WHERE
+ * contest_id IS NULL），全服全部历史实测 24ms。
+ */
+export async function loadEntrants(where: SQL, since: string | null): Promise<Entrant[]> {
+  const firstSolved = min(schema.submission.createTime)
+  const [people, solves] = await Promise.all([
+    db
+      .select({
+        id: schema.user.id,
+        username: schema.user.username,
+        className: schema.user.className,
+        avatar: schema.userProfile.avatar,
+      })
+      .from(schema.user)
+      .leftJoin(schema.userProfile, eq(schema.userProfile.userId, schema.user.id))
+      .where(where),
+    db
+      .select({ userId: schema.submission.userId, at: firstSolved })
+      .from(schema.submission)
+      .innerJoin(schema.user, eq(schema.user.id, schema.submission.userId))
+      .where(
+        and(
+          where,
+          isNull(schema.submission.contestId),
+          inArray(schema.submission.result, SOLVED_RESULTS),
+        ),
+      )
+      .groupBy(schema.submission.userId, schema.submission.problemId)
+      .having(since ? gte(firstSolved, since) : undefined),
+  ])
+
+  const byUser = new Map<number, string[]>()
+  for (const row of solves) {
+    if (!row.at) continue
+    const list = byUser.get(row.userId)
+    if (list) list.push(row.at)
+    else byUser.set(row.userId, [row.at])
+  }
+  return people.map((person) => {
+    const pairs = (byUser.get(person.id) ?? [])
+      .map((stamp) => [Date.parse(stamp), stamp] as const)
+      .sort((a, b) => a[0] - b[0])
+    return {
+      id: person.id,
+      username: person.username,
+      className: person.className,
+      avatar: avatarOf(person.avatar),
+      times: pairs.map(([time]) => time),
+      stamps: pairs.map(([, stamp]) => stamp),
+    }
+  })
+}
+
+/**
+ * `cutoff` 那一刻的名次（不给就是现在）。一样多的先做到的在前，再一样按 id ——
+ * 第三档不是凑数：同一秒做到的确实有（一节课的最后一道），没有稳定的兜底键名次会跳。
+ * `includeZero`：本班把一道没做对的也排上（全班名单），本年级 / 全服不排。
+ */
+export function standings(entrants: Entrant[], cutoff: number | null, includeZero: boolean) {
+  const list = entrants
+    .map((entrant) => {
+      let solved = entrant.times.length
+      if (cutoff !== null) {
+        solved = 0
+        while (solved < entrant.times.length && entrant.times[solved]! < cutoff) solved++
+      }
+      return {
+        entrant,
+        solved,
+        reached: solved ? entrant.times[solved - 1]! : Number.POSITIVE_INFINITY,
+        reachedAt: solved ? entrant.stamps[solved - 1]! : null,
+      }
+    })
+    .filter((row) => includeZero || row.solved > 0)
+    .sort((a, b) => b.solved - a.solved || a.reached - b.reached || a.entrant.id - b.entrant.id)
+  return list.map((row, index): Standing => ({
+    entrant: row.entrant,
+    rank: index + 1,
+    solved: row.solved,
+    reachedAt: row.reachedAt,
+  }))
+}
+
+/** 「要多关心的同学」：这学期做对不到这么多道 */
+const CARE_BELOW = 3
+/** 一档同分至少这么多人，才说「N 个人停在 x 道」 */
+const PLATEAU_MIN = 5
+/** 班级详情的每周人均列最近几周 */
+const DETAIL_WEEKS = 6
+
+/** 有班级的学生，这学期的做对时刻 —— 班级对抗和班级详情都从这一份算 */
+async function classedEntrants() {
+  const term = termStart()
+  const where = and(
+    rankedStudents,
+    isNotNull(schema.user.className),
+    ne(schema.user.className, ""),
+  )!
+  return { term, entrants: await loadEntrants(where, term) }
+}
+
+function battleFrom(entrants: Entrant[]) {
+  const week = Date.parse(weekStart())
+  const classes = new Map<string, { members: number; term: number; week: number }>()
+  for (const entrant of entrants) {
+    const entry = classes.get(entrant.className!) ?? { members: 0, term: 0, week: 0 }
+    entry.members++
+    entry.term += entrant.times.length
+    entry.week += entrant.times.filter((time) => time >= week).length
+    classes.set(entrant.className!, entry)
+  }
+  return [...classes]
+    .filter(([, entry]) => entry.term > 0)
+    .map(([className, entry]) => ({
+      className,
+      members: entry.members,
+      perCapita: rounded(entry.term / entry.members, 1),
+      weekGain: rounded(entry.week / entry.members, 1),
+    }))
+    .sort((a, b) => b.perCapita - a.perCapita || b.weekGain - a.weekGain)
+    .map((item, index) => ({ ...item, rank: index + 1 }) satisfies ClassBattleItem)
+}
+
+/**
+ * 班级对抗：全服每个班这学期人均做对几道，外加这周人均涨了多少。人均而不是总数 ——
+ * 班级人数从 11 到 58 都有，比总数等于比人多。这学期一道没做对的班不列（还没开始用）。
+ * 不计入排名的人分子分母都不算：抄来的题不该替全班加分。
+ */
+export async function classBattle() {
+  const { entrants } = await classedEntrants()
+  return { items: battleFrom(entrants) }
+}
+
+function average(values: number[]) {
+  return values.length ? values.reduce((sum, value) => sum + value, 0) / values.length : 0
+}
+
+function median(values: number[]) {
+  if (!values.length) return 0
+  const sorted = [...values].sort((a, b) => a - b)
+  const middle = Math.floor(sorted.length / 2)
+  return sorted.length % 2 ? sorted[middle]! : (sorted[middle - 1]! + sorted[middle]!) / 2
+}
+
+/**
+ * 班级详情，抽屉里的全部数字（也是班级 AI 分析的输入）。`withCare` 只对老师开：
+ * 「要多关心的同学」点了名，学生不该看到别人被点名。
+ */
+export async function classDetail(className: string, withCare: boolean): Promise<ClassDetail> {
+  const { term, entrants } = await classedEntrants()
+  const battle = battleFrom(entrants)
+  const mine = entrants.filter((entrant) => entrant.className === className)
+  const solved = mine.map((entrant) => entrant.times.length)
+  const desc = [...solved].sort((a, b) => b - a)
+  const tenth = Math.max(1, Math.ceil(mine.length / 10))
+
+  // 同年级在用的班：班级对抗里列着的（这学期做对过题）、班号前两位相同
+  const grade = className.slice(0, 2)
+  const gradeClasses = new Set(
+    battle.filter((item) => item.className.slice(0, 2) === grade).map((item) => item.className),
+  )
+  const gradeEntrants = entrants.filter((entrant) => gradeClasses.has(entrant.className!))
+  const gradeAvg = gradeEntrants.length
+    ? rounded(average(gradeEntrants.map((entrant) => entrant.times.length)), 1)
+    : null
+
+  const groups = new Map<number, number>()
+  for (const value of solved) if (value > 0) groups.set(value, (groups.get(value) ?? 0) + 1)
+  const [plateau] = [...groups]
+    .filter(([, n]) => n >= PLATEAU_MIN)
+    .sort((a, b) => b[1] - a[1] || b[0] - a[0])
+
+  // 每周：周一零点起算，从这学期第一周到这周，只留最近几周
+  const firstWeek = Date.parse(weekStart(term))
+  const thisWeek = Date.parse(weekStart())
+  const weeks: ClassDetail["weeks"] = []
+  for (let from = firstWeek; from <= thisWeek; from += WEEK_MS) {
+    const inWeek = (entrant: Entrant) =>
+      entrant.times.filter((time) => time >= from && time < from + WEEK_MS).length
+    weeks.push({
+      weekStart: new Date(from).toISOString(),
+      perCapita: mine.length ? rounded(average(mine.map(inWeek)), 1) : 0,
+      gradeAvg: gradeEntrants.length ? rounded(average(gradeEntrants.map(inWeek)), 1) : null,
+    })
+  }
+
+  let care: ClassDetail["care"] = null
+  if (withCare) {
+    const low = mine
+      .filter((entrant) => entrant.times.length < CARE_BELOW)
+      .sort((a, b) => a.times.length - b.times.length || a.id - b.id)
+    const submitted = low.length
+      ? await db
+          .select({ userId: schema.submission.userId, n: count() })
+          .from(schema.submission)
+          .where(
+            and(
+              inArray(
+                schema.submission.userId,
+                low.map((entrant) => entrant.id),
+              ),
+              isNull(schema.submission.contestId),
+              gte(schema.submission.createTime, term),
+            ),
+          )
+          .groupBy(schema.submission.userId)
+      : []
+    const counts = new Map(submitted.map((row) => [row.userId, row.n]))
+    care = low.map((entrant) => ({
+      user: sampleUser(entrant, null),
+      avatar: entrant.avatar,
+      solved: entrant.times.length,
+      submissions: counts.get(entrant.id) ?? 0,
+    }))
+  }
+
+  const item = battle.find((entry) => entry.className === className)
+  return {
+    className,
+    start: term,
+    members: mine.length,
+    rank: item?.rank ?? null,
+    battleSize: battle.length,
+    perCapita: mine.length ? rounded(average(solved), 1) : 0,
+    gradeAvg,
+    median: median(solved),
+    solvedMembers: solved.filter((value) => value > 0).length,
+    top10Avg: rounded(average(desc.slice(0, tenth)), 1),
+    bottom10Avg: rounded(average(desc.slice(-tenth)), 1),
+    plateau: plateau ? { solved: plateau[0], count: plateau[1] } : null,
+    distribution: solved,
+    weeks: weeks.slice(-DETAIL_WEEKS),
+    care,
+  } satisfies ClassDetail
+}
diff --git a/apps/web/src/oj/api.ts b/apps/web/src/oj/api.ts
index 2d0b6e2..6cee907 100644
--- a/apps/web/src/oj/api.ts
+++ b/apps/web/src/oj/api.ts
@@ -16,6 +16,7 @@ import {
   type KnowledgeMap,
   type ClassComparisonResponse,
   type ClassBattleItem,
+  type ClassDetail,
   type RankBoard,
   type RankPeriod,
   type RankScope,
@@ -245,6 +246,11 @@ export function getClassBattle() {
   return api.get<ClassBattleItem[]>("rankings/classes")
 }
 
+/** 班级详情（抽屉）：谁都能看，「要多关心的同学」只有老师拿得到 */
+export function getClassDetail(className: string) {
+  return api.get<ClassDetail>("rankings/class-detail", { params: { className } })
+}
+
 /** 本班最近几周的每周冠军 */
 export function getWeeklyChampions(className?: string) {
   return api.get<WeeklyChampion[]>("rankings/champions", {
diff --git a/apps/web/src/oj/rank/components/ChampionList.vue b/apps/web/src/oj/rank/components/ChampionList.vue
index ae18d9a..5ee2c91 100644
--- a/apps/web/src/oj/rank/components/ChampionList.vue
+++ b/apps/web/src/oj/rank/components/ChampionList.vue
@@ -5,7 +5,7 @@ import UserName from "shared/components/UserName.vue"
 import { parseTime } from "utils/functions"
 import RankAvatar from "./RankAvatar.vue"
 
-/** 本班最近几周的每周冠军，底下再挂这张榜上「冲得最猛」的那个人 */
+/** 本班最近几周的每周冠军，底下再挂这张榜上「进步最大」的那个人 */
 defineProps<{
   champions: WeeklyChampion[]
   hot: RankRow | null
@@ -51,7 +51,7 @@ function weekLabel(start: string) {
     </div>
     <span v-if="!champions.length" class="muted">最近几周还没有冠军</span>
     <div v-if="hot" class="row hot-line">
-      <span class="hot-tag">冲得最猛</span>
+      <span class="hot-tag">进步最大</span>
       <RankAvatar
         :username="hot.user.username"
         :avatar="hot.avatar"
diff --git a/apps/web/src/oj/rank/components/ClassBattle.vue b/apps/web/src/oj/rank/components/ClassBattle.vue
index 0b4abfc..3512eae 100644
--- a/apps/web/src/oj/rank/components/ClassBattle.vue
+++ b/apps/web/src/oj/rank/components/ClassBattle.vue
@@ -14,7 +14,10 @@ const props = defineProps<{
   teacher?: boolean
   /** 放在手机页签卡里：不要自己的边框和标题 */
   bare?: boolean
+  /** 显示「班级 PK」入口（原来排名页上那个按钮，管理员角色才有） */
+  pk?: boolean
 }>()
+const emit = defineEmits<{ pick: [className: string] }>()
 
 const theme = useThemeVars()
 const palette = useRankPalette()
@@ -52,7 +55,8 @@ function shortLabel(className: string) {
 <template>
   <div class="battle" :class="{ bare }">
     <div class="title">
-      <b v-if="!bare">班级对抗</b><span class="muted">人均做对 · 全服 · 绿字是这周涨的</span>
+      <b v-if="!bare">班级对抗</b><span class="muted">人均做对 · 全服 · 点班名看详情</span>
+      <router-link v-if="pk" to="/class" class="pk">班级 PK ›</router-link>
     </div>
     <div
       v-for="item in shown"
@@ -61,7 +65,9 @@ function shortLabel(className: string) {
       :class="{ mine: item.className === mine }"
     >
       <span class="rank">{{ item.rank }}</span>
-      <span class="name">{{ classLabel(item.className) }}</span>
+      <button class="name" title="看班级详情" @click="emit('pick', item.className)">
+        {{ classLabel(item.className) }}
+      </button>
       <span class="bar-box">
         <span
           class="bar"
@@ -132,6 +138,26 @@ function shortLabel(className: string) {
 
 .name {
   width: 86px;
+  padding: 0;
+  border: 0;
+  background: none;
+  font: inherit;
+  color: inherit;
+  text-align: left;
+  white-space: nowrap;
+  cursor: pointer;
+}
+
+.name:hover {
+  color: v-bind("theme.primaryColor");
+  text-decoration: underline;
+}
+
+.pk {
+  margin-left: auto;
+  font-size: 12px;
+  color: v-bind("theme.primaryColor");
+  text-decoration: none;
   white-space: nowrap;
 }
 
diff --git a/apps/web/src/oj/rank/components/ClassDetailDrawer.vue b/apps/web/src/oj/rank/components/ClassDetailDrawer.vue
new file mode 100644
index 0000000..3203721
--- /dev/null
+++ b/apps/web/src/oj/rank/components/ClassDetailDrawer.vue
@@ -0,0 +1,477 @@
+<script setup lang="ts">
+import type { ClassDetail } from "@oj2/contract"
+import { MdPreview } from "md-editor-v3"
+import "md-editor-v3/lib/preview.css"
+import { useThemeVars } from "naive-ui"
+import { getClassDetail } from "oj/api"
+import { classLabel } from "oj/submission/utils"
+import UserName from "shared/components/UserName.vue"
+import { useAIStream } from "shared/composables/aiStream"
+import { useBreakpoints } from "shared/composables/breakpoints"
+import { parseTime } from "utils/functions"
+import { useRankPalette } from "../palette"
+import RankAvatar from "./RankAvatar.vue"
+
+/**
+ * 班级详情（设计稿「班级详情 · 老师 / 学生」）：从右边滑出的抽屉，代替原来那个满是
+ * 四分位数、标准差、综合分的弹框。谁都能看；「要多关心的同学」和 AI 分析只给老师，
+ * AI 报告直接在抽屉里出，不再关掉再弹第二个框。
+ */
+const props = defineProps<{ className: string | null; teacher: boolean; pk: boolean }>()
+const show = defineModel<boolean>("show", { required: true })
+
+const router = useRouter()
+const message = useMessage()
+const theme = useThemeVars()
+const palette = useRankPalette()
+const { isDesktop } = useBreakpoints()
+
+const detail = ref<ClassDetail | null>(null)
+const loading = ref(false)
+const report = ref("")
+const ai = useAIStream()
+
+watch(
+  () => [show.value, props.className] as const,
+  async ([open, className]) => {
+    if (!open || !className) return
+    if (detail.value?.className !== className) {
+      report.value = ""
+      ai.abort()
+    }
+    loading.value = true
+    try {
+      detail.value = await getClassDetail(className)
+    } catch {
+      detail.value = null
+    } finally {
+      loading.value = false
+    }
+  },
+)
+
+/** 分布点阵：每个做对数一列，一列里一个点一个同学；做对不到 3 道的老师那边标红 */
+const columns = computed(() => {
+  const counts = new Map<number, number>()
+  for (const n of detail.value?.distribution ?? []) counts.set(n, (counts.get(n) ?? 0) + 1)
+  return [...counts].sort((a, b) => a[0] - b[0]).map(([solved, people]) => ({ solved, people }))
+})
+const dot = computed(() => {
+  const tallest = Math.max(1, ...columns.value.map((column) => column.people))
+  return Math.max(4, Math.min(10, Math.floor(172 / tallest) - 2))
+})
+
+const weekMax = computed(() =>
+  Math.max(
+    1,
+    ...(detail.value?.weeks ?? []).flatMap((week) => [week.perCapita, week.gradeAvg ?? 0]),
+  ),
+)
+
+async function analyze() {
+  if (!props.className) return
+  report.value = ""
+  try {
+    await ai.run(
+      "ai/class-analysis",
+      { className: props.className },
+      { onDelta: (content) => (report.value += content) },
+    )
+  } catch (error) {
+    message.error((error as Error).message)
+  }
+}
+
+function go(path: string, query: Record<string, string>) {
+  show.value = false
+  router.push({ path, query })
+}
+</script>
+
+<template>
+  <n-drawer v-model:show="show" :width="isDesktop ? 560 : '100%'" placement="right">
+    <n-drawer-content closable :native-scrollbar="false">
+      <template #header>
+        <div class="head">
+          <span class="title">{{ className ? classLabel(className) : "班级详情" }}</span>
+          <span v-if="detail" class="muted">
+            {{ detail.members }} 人 · 这学期（{{ parseTime(detail.start, "M月D日") }}起）
+            <template v-if="detail.rank"> · 班级对抗第 {{ detail.rank }}</template>
+          </span>
+        </div>
+      </template>
+
+      <n-spin :show="loading">
+        <div v-if="detail" class="body">
+          <div class="bigs">
+            <div class="big">
+              <span>人均做对</span><b>{{ detail.perCapita }}</b>
+              <span v-if="detail.gradeAvg !== null">年级平均 {{ detail.gradeAvg }}</span>
+            </div>
+            <div class="big">
+              <span>中间那位同学做对</span><b>{{ detail.median }} 道</b><span>一半人比他多</span>
+            </div>
+            <div class="big">
+              <span>做对过题的</span>
+              <b
+                >{{ detail.solvedMembers }} <small>/ {{ detail.members }} 人</small></b
+              >
+              <span>{{
+                detail.members - detail.solvedMembers
+                  ? `${detail.members - detail.solvedMembers} 人还没做对`
+                  : "人人都做对过"
+              }}</span>
+            </div>
+          </div>
+
+          <section>
+            <div class="sec-title">
+              全班分布<span class="muted">一个点一个同学，下面是这学期做对几道</span>
+            </div>
+            <div class="dots">
+              <div v-for="column in columns" :key="column.solved" class="dot-col">
+                <div class="stack">
+                  <span
+                    v-for="i in column.people"
+                    :key="i"
+                    class="dot"
+                    :style="{
+                      width: `${dot}px`,
+                      height: `${dot}px`,
+                      background: teacher && column.solved < 3 ? '#e5484d' : '#9fb3c8',
+                    }"
+                  />
+                </div>
+                <span class="axis">{{ column.solved }}</span>
+              </div>
+            </div>
+            <span class="line">
+              前 10% 平均 <b>{{ detail.top10Avg }}</b> 道 · 后 10% 平均
+              <b>{{ detail.bottom10Avg }}</b> 道
+              <template v-if="detail.plateau">
+                · {{ detail.plateau.count }} 个人停在 {{ detail.plateau.solved }} 道</template
+              >
+            </span>
+          </section>
+
+          <section v-if="detail.weeks.length">
+            <div class="sec-title">
+              每周人均新做对
+              <span class="key"><i :style="{ background: palette.me }" />本班</span>
+              <span v-if="detail.gradeAvg !== null" class="key"
+                ><i :style="{ background: palette.bar }" />年级平均</span
+              >
+            </div>
+            <div class="weeks">
+              <div v-for="week in detail.weeks" :key="week.weekStart" class="week">
+                <div class="pair">
+                  <div class="bar-col">
+                    <span class="v me">{{ week.perCapita }}</span>
+                    <span
+                      class="bar"
+                      :style="{
+                        height: `${Math.max(2, (week.perCapita / weekMax) * 90)}px`,
+                        background: palette.me,
+                      }"
+                    />
+                  </div>
+                  <div v-if="week.gradeAvg !== null" class="bar-col">
+                    <span class="v">{{ week.gradeAvg }}</span>
+                    <span
+                      class="bar"
+                      :style="{
+                        height: `${Math.max(2, (week.gradeAvg / weekMax) * 90)}px`,
+                        background: palette.bar,
+                      }"
+                    />
+                  </div>
+                </div>
+                <span class="axis">{{ parseTime(week.weekStart, "M月D日") }}那周</span>
+              </div>
+            </div>
+          </section>
+
+          <section v-if="detail.care">
+            <div class="sec-title">
+              要多关心的同学<span class="muted">这学期做对不到 3 道 · 只有老师看得到</span>
+            </div>
+            <div v-for="row in detail.care" :key="row.user.id" class="care">
+              <RankAvatar :username="row.user.username" :avatar="row.avatar" :size="20" />
+              <UserName :username="row.user.username" />
+              <span class="muted">这学期 {{ row.solved }} 道 · 交过 {{ row.submissions }} 次</span>
+              <div class="spacer" />
+              <a
+                href="#"
+                @click.prevent="
+                  go('/submission', { username: row.user.username, exactUsername: '1' })
+                "
+                >看他的提交 ›</a
+              >
+              <a href="#" @click.prevent="go('/ai-analysis', { username: row.user.username })"
+                >智能分析 ›</a
+              >
+            </div>
+            <span v-if="!detail.care.length" class="muted">没有，这学期人人都做对 3 道以上</span>
+          </section>
+
+          <section v-if="teacher" class="ai">
+            <div class="ai-head">
+              <svg
+                width="18"
+                height="18"
+                viewBox="0 0 24 24"
+                fill="none"
+                stroke="currentColor"
+                stroke-width="2"
+                stroke-linecap="round"
+                stroke-linejoin="round"
+                aria-hidden="true"
+              >
+                <path d="M12 3l1.8 4.7L18.5 9.5l-4.7 1.8L12 16l-1.8-4.7L5.5 9.5l4.7-1.8z" />
+              </svg>
+              <b>AI 分析这个班</b>
+              <span class="muted">根据上面这些数字写，仅供参考</span>
+              <div class="spacer" />
+              <n-button
+                size="small"
+                :type="report ? 'default' : 'info'"
+                :loading="ai.running.value"
+                @click="analyze"
+              >
+                {{ report ? "重新分析" : "开始分析" }}
+              </n-button>
+            </div>
+            <span v-if="ai.waiting.value" class="muted">正在看这个班的数据…</span>
+            <MdPreview v-if="report" class="report" :model-value="report" />
+          </section>
+
+          <a v-if="pk" href="#" class="pk" @click.prevent="go('/class', {})"
+            >和别的班比 → 班级 PK ›</a
+          >
+        </div>
+        <div v-else-if="!loading" class="muted">这个班的数据没取到</div>
+      </n-spin>
+    </n-drawer-content>
+  </n-drawer>
+</template>
+
+<style scoped>
+.head {
+  display: flex;
+  flex-direction: column;
+  gap: 3px;
+}
+
+.title {
+  font-size: 20px;
+  font-weight: 700;
+}
+
+.muted {
+  font-size: 12px;
+  font-weight: 400;
+  color: v-bind("theme.textColor3");
+}
+
+.body {
+  display: flex;
+  flex-direction: column;
+  gap: 20px;
+}
+
+.bigs {
+  display: flex;
+  gap: 8px;
+}
+
+.big {
+  flex: 1;
+  min-width: 0;
+  padding: 10px 12px;
+  border-radius: 6px;
+  background: v-bind("theme.actionColor");
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+}
+
+.big b {
+  font-size: 24px;
+  font-variant-numeric: tabular-nums;
+}
+
+.big b small {
+  font-size: 13px;
+  font-weight: 400;
+  color: v-bind("theme.textColor3");
+}
+
+.big span {
+  font-size: 12px;
+  color: v-bind("theme.textColor3");
+}
+
+section {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.sec-title {
+  display: flex;
+  align-items: baseline;
+  flex-wrap: wrap;
+  gap: 8px;
+  font-size: 13px;
+  font-weight: 600;
+  color: v-bind("theme.textColor2");
+}
+
+.dots {
+  display: flex;
+  align-items: flex-end;
+  gap: 2px;
+}
+
+.dot-col {
+  flex: 1;
+  min-width: 0;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 4px;
+}
+
+.stack {
+  height: 172px;
+  display: flex;
+  flex-direction: column-reverse;
+  align-items: center;
+  gap: 2px;
+  padding-bottom: 4px;
+  border-bottom: 1px solid v-bind("theme.dividerColor");
+  width: 100%;
+}
+
+.dot {
+  border-radius: 50%;
+  flex-shrink: 0;
+}
+
+.axis {
+  font-size: 11px;
+  color: v-bind("theme.textColor3");
+  font-variant-numeric: tabular-nums;
+  white-space: nowrap;
+}
+
+.line {
+  font-size: 13px;
+  color: v-bind("theme.textColor2");
+}
+
+.key {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  font-weight: 400;
+  font-size: 12px;
+}
+
+.key i {
+  width: 10px;
+  height: 10px;
+  border-radius: 2px;
+}
+
+.weeks {
+  display: flex;
+  gap: 4px;
+}
+
+.week {
+  flex: 1;
+  min-width: 0;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 4px;
+}
+
+.pair {
+  height: 110px;
+  display: flex;
+  align-items: flex-end;
+  gap: 4px;
+}
+
+.bar-col {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 2px;
+}
+
+.bar {
+  width: 16px;
+  border-radius: 3px 3px 0 0;
+}
+
+.v {
+  font-size: 11px;
+  color: v-bind("theme.textColor3");
+  font-variant-numeric: tabular-nums;
+}
+
+.v.me {
+  color: #18a058;
+  font-weight: 600;
+}
+
+.care {
+  height: 30px;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  font-size: 13px;
+}
+
+.care a,
+.pk {
+  font-size: 13px;
+  color: v-bind("theme.primaryColor");
+  text-decoration: none;
+  white-space: nowrap;
+}
+
+.spacer {
+  flex-grow: 1;
+}
+
+.ai {
+  padding: 12px 14px;
+  border-radius: 8px;
+  border: 1px solid rgba(47, 111, 208, 0.3);
+  background: rgba(47, 111, 208, 0.05);
+}
+
+.ai-head {
+  display: flex;
+  align-items: center;
+  flex-wrap: wrap;
+  gap: 8px;
+  color: #2f6fd0;
+}
+
+.ai-head b {
+  color: v-bind("theme.textColor1");
+}
+
+.report {
+  background: transparent;
+}
+
+.report :deep(.md-editor-preview-wrapper) {
+  padding: 0;
+}
+</style>
diff --git a/apps/web/src/oj/rank/components/RankAvatar.vue b/apps/web/src/oj/rank/components/RankAvatar.vue
index e90d2e2..b665192 100644
--- a/apps/web/src/oj/rank/components/RankAvatar.vue
+++ b/apps/web/src/oj/rank/components/RankAvatar.vue
@@ -6,7 +6,7 @@ import { USERNAME_CLASS_RE } from "utils/constants"
 /**
  * 排名页的头像。九成以上的学生没换过头像（1797 个号是 default.png），一排一模一样的
  * 默认图分不出人，所以默认头像画成「名字最后一个字 + 彩色圆」，颜色按用户名固定 ——
- * 同一个人在领奖台、赛道、对手卡里是同一个颜色。自己是实心绿。
+ * 同一个人在领奖台、赛道、「你」那张卡里是同一个颜色。自己是实心绿。
  */
 const props = defineProps<{
   username: string
diff --git a/apps/web/src/oj/rank/components/RankMe.vue b/apps/web/src/oj/rank/components/RankMe.vue
index e2788cb..df23ba0 100644
--- a/apps/web/src/oj/rank/components/RankMe.vue
+++ b/apps/web/src/oj/rank/components/RankMe.vue
@@ -14,7 +14,10 @@ export interface MiniRank {
 
 /**
  * 「你」那张卡：大字第几名、比周一升了几名，一句最能推人一把的话（离领奖台几道 / 升了几名），
- * 再是两个对手 —— 前面那个要追的、后面那个在追你的，差几秒、差几道都写出来。
+ * 再是前一名、后一名，差几秒、差几道都写出来。
+ *
+ * 用词只说位置（前一名 / 后一名 / 进步最大），不用「追」「对手」「冲」：用户指出
+ * 「要追的」「追你」会被中学生读成追求谁，「冲得最猛」也容易误会。
  */
 const props = defineProps<{
   me: RankRow
@@ -25,7 +28,7 @@ const props = defineProps<{
   total: number
   label: string
   minis: MiniRank[]
-  /** 手机：对手的说明换到名字下面一行，别被截断 */
+  /** 手机：前后一名的说明换到名字下面一行，别被截断 */
   compact?: boolean
 }>()
 
@@ -33,7 +36,7 @@ const theme = useThemeVars()
 
 const headline = computed(() => {
   const { me, ahead, third } = props
-  if (me.rank === 1) return "你是第一名，后面的人在追你"
+  if (me.rank === 1) return "你是第一名"
   if (me.rank <= 3 && ahead)
     return `你在领奖台上 · 再做对 ${toPass(me, ahead)} 道就是第 ${ahead.rank} 名`
   if (third) {
@@ -47,13 +50,13 @@ const headline = computed(() => {
 
 function chaseNote(me: RankRow, ahead: RankRow) {
   if (ahead.solved === me.solved && ahead.reachedAt && me.reachedAt)
-    return `早你 ${gapText(ahead.reachedAt, me.reachedAt)}做到 ${me.solved} 道`
+    return `比你早 ${gapText(ahead.reachedAt, me.reachedAt)}做到 ${me.solved} 道`
   return `比你多 ${ahead.solved - me.solved} 道`
 }
 
 function threatNote(me: RankRow, behind: RankRow) {
   if (behind.solved === me.solved && behind.reachedAt && me.reachedAt)
-    return `只比你晚 ${gapText(me.reachedAt, behind.reachedAt)}，再做对 1 道就超过你`
+    return `比你晚 ${gapText(me.reachedAt, behind.reachedAt)}做到 ${me.solved} 道`
   if (!behind.solved) return "还没做对"
   return `比你少 ${me.solved - behind.solved} 道`
 }
@@ -92,13 +95,13 @@ function threatNote(me: RankRow, behind: RankRow) {
       <b>{{ headline }}</b>
     </div>
     <div v-if="ahead" class="rival">
-      <span class="tag chase">要追</span>
+      <span class="tag chase">前一名</span>
       <RankAvatar :username="ahead.user.username" :avatar="ahead.avatar" :size="20" />
       <UserName :username="ahead.user.username" class="rival-name" />
       <span class="note">{{ chaseNote(me, ahead) }}</span>
     </div>
     <div v-if="behind" class="rival">
-      <span class="tag threat">追你</span>
+      <span class="tag threat">后一名</span>
       <RankAvatar :username="behind.user.username" :avatar="behind.avatar" :size="20" />
       <UserName :username="behind.user.username" class="rival-name" />
       <span class="note">{{ threatNote(me, behind) }}</span>
@@ -112,6 +115,22 @@ function threatNote(me: RankRow, behind: RankRow) {
         <b v-else class="none">没上榜</b>
       </button>
     </div>
+    <router-link to="/ai-analysis" class="analysis">
+      <svg
+        width="15"
+        height="15"
+        viewBox="0 0 24 24"
+        fill="none"
+        stroke="currentColor"
+        stroke-width="2"
+        stroke-linecap="round"
+        stroke-linejoin="round"
+        aria-hidden="true"
+      >
+        <path d="M12 3l1.8 4.7L18.5 9.5l-4.7 1.8L12 16l-1.8-4.7L5.5 9.5l4.7-1.8z" />
+      </svg>
+      看我的智能分析：哪类题卡得多、哪段时间最常做题 ›
+    </router-link>
   </div>
 </template>
 
@@ -238,6 +257,21 @@ function threatNote(me: RankRow, behind: RankRow) {
   background: rgba(199, 106, 18, 0.12);
 }
 
+.analysis {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding-top: 8px;
+  border-top: 1px solid rgba(24, 160, 88, 0.3);
+  font-size: 13px;
+  color: #2f6fd0;
+  text-decoration: none;
+}
+
+.analysis:hover {
+  text-decoration: underline;
+}
+
 .minis {
   display: flex;
   gap: 6px;
diff --git a/apps/web/src/oj/rank/components/RankPodium.vue b/apps/web/src/oj/rank/components/RankPodium.vue
index 5df78b2..07521ad 100644
--- a/apps/web/src/oj/rank/components/RankPodium.vue
+++ b/apps/web/src/oj/rank/components/RankPodium.vue
@@ -7,7 +7,7 @@ import RankAvatar from "./RankAvatar.vue"
 
 /**
  * 领奖台：前三名站在台阶上，第一名戴皇冠。赛道从第 4 名接着排，前三不再出现第二遍。
- * 你要追的人站在台上时台阶描蓝边、挂「你要追的」，和赛道里的蓝条是一回事。
+ * 你的前一名站在台上时台阶描蓝边、挂「前一名」，和赛道里的蓝条是一回事。
  */
 const props = defineProps<{
   rows: RankRow[]
@@ -49,8 +49,8 @@ const HEIGHTS: Record<number, number> = { 1: 50, 2: 38, 3: 30 }
         >
           <path d="M3 8l4.5 4L12 5l4.5 7L21 8l-2 11H5z" />
         </svg>
-        <span v-if="row.user.id === chaseId" class="tag chase">你要追的</span>
-        <span v-else-if="row.user.id === threatId" class="tag threat">在追你</span>
+        <span v-if="row.user.id === chaseId" class="tag chase">前一名</span>
+        <span v-else-if="row.user.id === threatId" class="tag threat">后一名</span>
         <span v-else-if="row.user.id === meId" class="tag me">你</span>
       </div>
       <RankAvatar
diff --git a/apps/web/src/oj/rank/components/RankTrack.vue b/apps/web/src/oj/rank/components/RankTrack.vue
index 8cd6ff1..3cc7995 100644
--- a/apps/web/src/oj/rank/components/RankTrack.vue
+++ b/apps/web/src/oj/rank/components/RankTrack.vue
@@ -36,6 +36,7 @@ const emit = defineEmits<{
   open: [username: string]
   expand: []
   submissions: [username: string]
+  analysis: [username: string]
   hide: [row: RankRow]
 }>()
 
@@ -130,11 +131,13 @@ function width(row: RankRow) {
 
 const menu: DropdownOption[] = [
   { label: "看他的提交", key: "submissions" },
+  { label: "看他的智能分析", key: "analysis" },
   { label: "不计入排名…", key: "hide" },
 ]
 
 function onMenu(key: string, row: RankRow) {
   if (key === "submissions") emit("submissions", row.user.username)
+  else if (key === "analysis") emit("analysis", row.user.username)
   else emit("hide", row)
 }
 </script>
@@ -165,9 +168,9 @@ function onMenu(key: string, row: RankRow) {
           <button class="who" @click="emit('open', item.row.user.username)">
             <UserName :username="item.row.user.username" />
           </button>
-          <span v-if="item.row.user.id === chaseId" class="tag chase">要追</span>
-          <span v-else-if="item.row.user.id === threatId" class="tag threat">追你</span>
-          <span v-else-if="item.row.user.id === hotId" class="tag hot">冲得最猛</span>
+          <span v-if="item.row.user.id === chaseId" class="tag chase">前一名</span>
+          <span v-else-if="item.row.user.id === threatId" class="tag threat">后一名</span>
+          <span v-else-if="item.row.user.id === hotId" class="tag hot">进步最大</span>
           <span class="solved">{{ item.row.solved }}</span>
           <span class="change">
             <span v-if="(item.row.change ?? 0) > 0" class="up">↑{{ item.row.change }}</span>
@@ -208,9 +211,9 @@ function onMenu(key: string, row: RankRow) {
             <span v-else-if="item.row.change === 0" class="flat">—</span>
           </span>
           <span class="tag-box">
-            <span v-if="item.row.user.id === chaseId" class="tag chase">要追</span>
-            <span v-else-if="item.row.user.id === threatId" class="tag threat">追你</span>
-            <span v-else-if="item.row.user.id === hotId" class="tag hot">冲得最猛</span>
+            <span v-if="item.row.user.id === chaseId" class="tag chase">前一名</span>
+            <span v-else-if="item.row.user.id === threatId" class="tag threat">后一名</span>
+            <span v-else-if="item.row.user.id === hotId" class="tag hot">进步最大</span>
           </span>
           <n-dropdown
             v-if="teacher"
diff --git a/apps/web/src/oj/rank/components/RankTrend.vue b/apps/web/src/oj/rank/components/RankTrend.vue
index 9081fda..4a17967 100644
--- a/apps/web/src/oj/rank/components/RankTrend.vue
+++ b/apps/web/src/oj/rank/components/RankTrend.vue
@@ -4,7 +4,7 @@ import { useThemeVars } from "naive-ui"
 import { parseTime } from "utils/functions"
 
 /**
- * 我和两个对手每周日晚上的名次。名次越小越好，所以纵轴倒过来（第 1 在最上面）。
+ * 我和前后一名每周日晚上的名次。名次越小越好，所以纵轴倒过来（第 1 在最上面）。
  * 线的末端直接写名字，不要图例 —— 三条线，看名字比对颜色快。
  */
 const props = defineProps<{
@@ -88,7 +88,7 @@ const ends = computed(() => {
 </script>
 
 <template>
-  <svg :viewBox="`0 0 ${W} ${H}`" class="chart" role="img" aria-label="我和对手每周的名次">
+  <svg :viewBox="`0 0 ${W} ${H}`" class="chart" role="img" aria-label="我和前后一名每周的名次">
     <g v-for="tick in ticks" :key="tick">
       <line :x1="PAD.left" :x2="W - PAD.right" :y1="y(tick)" :y2="y(tick)" class="grid" />
       <text :x="PAD.left - 6" :y="y(tick) + 4" text-anchor="end" class="axis">第 {{ tick }}</text>
diff --git a/apps/web/src/oj/rank/list.vue b/apps/web/src/oj/rank/list.vue
index d0c886a..ec410c1 100644
--- a/apps/web/src/oj/rank/list.vue
+++ b/apps/web/src/oj/rank/list.vue
@@ -18,6 +18,7 @@ import { USERNAME_CLASS_RE } from "utils/constants"
 import { parseTime } from "utils/functions"
 import ChampionList from "./components/ChampionList.vue"
 import ClassBattle from "./components/ClassBattle.vue"
+import ClassDetailDrawer from "./components/ClassDetailDrawer.vue"
 import RankMe, { type MiniRank } from "./components/RankMe.vue"
 import RankPodium from "./components/RankPodium.vue"
 import RankTrack from "./components/RankTrack.vue"
@@ -86,8 +87,11 @@ async function load() {
   loading.value = true
   try {
     board.value = await fetchBoard(scope.value, period.value)
-    if (teacher.value && !teacherClass.value && board.value.scope !== "all")
-      teacherClass.value = board.value.scope === "class" ? (board.value.className ?? "") : ""
+    // 老师在「全部」时点了本班：后端挑了最近上课的班，回填到下拉框（这一下不用再取一遍）
+    if (teacher.value && !teacherClass.value && board.value.scope === "class") {
+      backfilling = true
+      teacherClass.value = board.value.className ?? ""
+    }
   } catch {
     board.value = null
   } finally {
@@ -131,6 +135,9 @@ async function expand() {
   }
 }
 
+let backfilling = false
+
+/** 范围、时间、老师选的班：三个一起变（下拉框选班会顺手改范围）也只取一次 */
 watch([scope, period, teacherClass], () => {
   router.replace({
     query: {
@@ -140,19 +147,15 @@ watch([scope, period, teacherClass], () => {
       class: teacher.value && teacherClass.value ? teacherClass.value : undefined,
     },
   })
-})
-watch([scope, period], load)
-watch(teacherClass, (value, old) => {
-  // 后端回填的那一下（空 → 班号）不用再取一遍
-  if (old || !board.value || board.value.className !== value) {
-    cache.clear()
-    load()
-  }
+  if (backfilling) backfilling = false
+  else load()
 })
 
 onMounted(async () => {
   if (!userStore.user) await userStore.getMyProfile().catch(() => {})
-  scope.value = pick(route.query.scope, SCOPE_OPTIONS, canScopeClass.value ? "class" : "all")
+  // 老师默认看全部（用户定的），要看哪个班自己在下拉框里选；学生默认看本班
+  const fallback = teacher.value ? "all" : canScopeClass.value ? "class" : "all"
+  scope.value = pick(route.query.scope, SCOPE_OPTIONS, fallback)
   if (!canScopeClass.value && scope.value !== "all") scope.value = "all"
   loadBattle()
   // scope 从 "all" 改成别的会触发 watch 去取；没改就自己取
@@ -160,7 +163,19 @@ onMounted(async () => {
 })
 
 /** 班级那几块（走势、这周本班、每周冠军、班级对抗高亮）对的是哪个班 */
-const classContext = computed(() => (teacher.value ? teacherClass.value : myClass.value) || null)
+const classContext = computed(
+  () => (teacher.value ? (scope.value === "all" ? "" : teacherClass.value) : myClass.value) || null,
+)
+
+/** 老师的班级下拉框：「全部」就是全服，选了班就切到本班（本年级时留在本年级） */
+const pickedClass = computed({
+  get: () => (scope.value === "all" ? "" : teacherClass.value),
+  set: (value: string) => {
+    teacherClass.value = value
+    if (!value) scope.value = "all"
+    else if (scope.value === "all") scope.value = "class"
+  },
+})
 
 const rows = computed(() => board.value?.rows ?? [])
 const podium = computed(() => rows.value.filter((row) => row.rank <= 3 && row.solved > 0))
@@ -239,7 +254,10 @@ const teacherClassOptions = computed(() => {
   const list = configStore.config?.classList ?? []
   const all =
     teacherClass.value && !list.includes(teacherClass.value) ? [teacherClass.value, ...list] : list
-  return all.map((name) => ({ label: classLabel(name), value: name }))
+  return [
+    { label: "全部", value: "" },
+    ...all.map((name) => ({ label: classLabel(name), value: name })),
+  ]
 })
 
 const myBattle = computed(() => battle.value.find((item) => item.className === classContext.value))
@@ -250,7 +268,7 @@ const daysLeft = computed(() => {
   return Math.max(1, Math.ceil((Date.parse(start) + 7 * 86_400_000 - Date.now()) / 86_400_000))
 })
 
-/** 走势图三条线：在追你的、你要追的、你（画在最上面） */
+/** 走势图三条线：后一名、前一名、你（画在最上面） */
 const trendLines = computed(() => {
   const b = board.value
   if (!b?.me) return []
@@ -287,10 +305,23 @@ watch(phoneTabs, (tabs) => {
   if (!tabs.some((tab) => tab.key === phoneTab.value)) phoneTab.value = "battle"
 })
 
+/** 班级详情（+ 老师的 AI 分析）：点班级对抗里的班名、或老师「这个班」卡上的按钮 */
+const detailClass = ref<string | null>(null)
+const showDetail = ref(false)
+function openDetail(className: string) {
+  detailClass.value = className
+  showDetail.value = true
+}
+
 function open(username: string) {
   router.push({ path: "/user", query: { name: username } })
 }
 
+/** 老师看某个学生的智能分析（那一页本来就支持 ?username=） */
+function openAnalysis(username: string) {
+  router.push({ path: "/ai-analysis", query: { username } })
+}
+
 function openSubmissions(username: string) {
   router.push({ path: "/submission", query: { username, exactUsername: "1" } })
 }
@@ -350,8 +381,8 @@ async function restore(userId: number) {
         </button>
       </div>
       <n-select
-        v-if="teacher && scope !== 'all'"
-        v-model:value="teacherClass"
+        v-if="teacher"
+        v-model:value="pickedClass"
         class="class-select"
         size="small"
         filterable
@@ -373,8 +404,8 @@ async function restore(userId: number) {
             <div class="spacer" />
             <span v-if="!teacher && me" class="legend">
               <span><i :style="{ background: palette.me }" />你</span>
-              <span v-if="board.ahead"><i :style="{ background: palette.chase }" />你要追的</span>
-              <span v-if="board.behind"><i :style="{ background: palette.threat }" />在追你的</span>
+              <span v-if="board.ahead"><i :style="{ background: palette.chase }" />前一名</span>
+              <span v-if="board.behind"><i :style="{ background: palette.threat }" />后一名</span>
               <span v-if="mateClass"><i :style="{ background: palette.mate }" />你们班</span>
             </span>
           </div>
@@ -402,6 +433,7 @@ async function restore(userId: number) {
             @open="open"
             @expand="expand"
             @submissions="openSubmissions"
+            @analysis="openAnalysis"
             @hide="hide"
           />
         </template>
@@ -438,6 +470,18 @@ async function restore(userId: number) {
                 <span>这周人均涨</span><b>+{{ myBattle.weekGain }}</b>
               </div>
             </div>
+            <div class="actions">
+              <n-button
+                v-if="classContext"
+                size="small"
+                secondary
+                type="info"
+                @click="openDetail(classContext)"
+              >
+                班级详情 · AI 分析
+              </n-button>
+              <n-button size="small" secondary @click="router.push('/class')">班级 PK</n-button>
+            </div>
             <div class="hidden-list">
               <span class="hidden-title">不计入排名的人</span>
               <template v-if="board.scope === 'class'">
@@ -457,13 +501,20 @@ async function restore(userId: number) {
             <span class="muted">做对 1 道新题就能上榜</span>
           </div>
         </template>
-        <ClassBattle v-if="isDesktop" :items="battle" :mine="classContext" :teacher="teacher" />
+        <ClassBattle
+          v-if="isDesktop"
+          :items="battle"
+          :mine="classContext"
+          :teacher="teacher"
+          :pk="userStore.isAdminRole"
+          @pick="openDetail"
+        />
       </aside>
     </div>
     <div v-if="isDesktop && classContext" class="below">
       <div v-if="board?.trend && me" class="card">
         <div class="card-title">
-          <b>我和对手的名次</b><span class="muted">每周日晚上 · 越高越好</span>
+          <b>我和前后一名的名次</b><span class="muted">每周日晚上 · 越高越好</span>
         </div>
         <RankTrend :trend="board.trend" :lines="trendLines" />
       </div>
@@ -509,6 +560,8 @@ async function restore(userId: number) {
           :items="battle"
           :mine="classContext"
           :teacher="teacher"
+          :pk="userStore.isAdminRole"
+          @pick="openDetail"
         />
         <RankTrend
           v-else-if="phoneTab === 'trend' && board?.trend"
@@ -529,6 +582,12 @@ async function restore(userId: number) {
         />
       </div>
     </div>
+    <ClassDetailDrawer
+      v-model:show="showDetail"
+      :class-name="detailClass"
+      :teacher="teacher"
+      :pk="userStore.isAdminRole"
+    />
   </div>
 </template>
 
@@ -709,6 +768,11 @@ async function restore(userId: number) {
   font-variant-numeric: tabular-nums;
 }
 
+.actions {
+  display: flex;
+  gap: 8px;
+}
+
 .hidden-list {
   display: flex;
   flex-direction: column;
diff --git a/apps/web/src/oj/rank/palette.ts b/apps/web/src/oj/rank/palette.ts
index a839763..b1880d9 100644
--- a/apps/web/src/oj/rank/palette.ts
+++ b/apps/web/src/oj/rank/palette.ts
@@ -1,8 +1,8 @@
 import { useDark } from "@vueuse/core"
 
 /**
- * 排名页的几种颜色（设计稿「排名重设计」G1）。用户说「颜色可以保留」：你绿、你要追的蓝、
- * 在追你的橙、本年级 / 全服里你们班的人浅绿，其余灰；前三名金银铜。
+ * 排名页的几种颜色（设计稿「排名重设计」G1）。用户说「颜色可以保留」：你绿、前一名蓝、
+ * 后一名橙、本年级 / 全服里你们班的人浅绿，其余灰；前三名金银铜。
  * 暗色下灰条和浅绿换深一档，不然在暗底上发白。
  */
 export function useRankPalette() {
diff --git a/apps/web/src/oj/rank/utils.ts b/apps/web/src/oj/rank/utils.ts
index 7c7053b..c9d9a61 100644
--- a/apps/web/src/oj/rank/utils.ts
+++ b/apps/web/src/oj/rank/utils.ts
@@ -53,7 +53,7 @@ export function toPass(me: RankRow, target: RankRow) {
   return target.solved - me.solved + 1
 }
 
-/** 这张榜上升得最猛的人（至少升 3 名才算），给他挂「冲得最猛」 */
+/** 这张榜上升得最多的人（至少升 3 名才算），给他挂「进步最大」 */
 export function hottest(rows: RankRow[]) {
   let best: RankRow | null = null
   for (const row of rows) {
diff --git a/packages/contract/src/ai.ts b/packages/contract/src/ai.ts
index f996975..10c89b6 100644
--- a/packages/contract/src/ai.ts
+++ b/packages/contract/src/ai.ts
@@ -232,8 +232,12 @@ export type HintDiagnosis = z.infer<typeof hintDiagnosisSchema>
  */
 export const aiHintFeedbackRequestSchema = z.object({ helpful: z.boolean() })
 
+/**
+ * 班级 AI 分析只传班号，数字在服务端按「班级详情」那一套现算 —— 原来是前端把弹框里的
+ * 统计值整包传上来，报告和抽屉里看到的数字可能对不上
+ */
 export const classAnalysisRequestSchema = z.object({
-  comparison: z.record(z.string(), z.unknown()),
+  className: z.string().trim().min(1).max(32),
 })
 
 export const classPkAnalysisRequestSchema = z.object({
diff --git a/packages/contract/src/ranking.ts b/packages/contract/src/ranking.ts
index d6139f6..d52a3d3 100644
--- a/packages/contract/src/ranking.ts
+++ b/packages/contract/src/ranking.ts
@@ -29,7 +29,7 @@ export const rankRowSchema = z.object({
   change: z.number().int().nullable(),
 })
 
-/** 我和对手每周的名次，给「我和对手的名次」那张走势图 */
+/** 我和前后一名每周的名次，给「我和前后一名的名次」那张走势图 */
 export const rankTrendSchema = z.object({
   /** 每个点的时刻（周一零点，也就是上周日晚上），最后一个是现在 */
   points: z.array(z.string()),
@@ -101,3 +101,48 @@ export type RankBoard = z.infer<typeof rankBoardSchema>
 export type ClassBattleItem = z.infer<typeof classBattleItemSchema>
 export type WeeklyChampion = z.infer<typeof weeklyChampionSchema>
 export type RankHiddenRequest = z.infer<typeof rankHiddenRequestSchema>
+
+/**
+ * 班级详情（设计稿「班级详情 · 老师 / 学生」）。原来弹框里的四分位数、四分位距、标准差、
+ * 综合分都去掉了，只留一眼看得懂的数：人均、中间那位同学、做对过的人、前后 10%、全班分布、
+ * 每周人均和年级比。口径和排名页一样：这学期第一次做对的题，不计入排名的人不算。
+ */
+export const classDetailSchema = z.object({
+  className: z.string(),
+  /** 这学期从哪天算起 */
+  start: z.string(),
+  members: z.number().int().nonnegative(),
+  /** 班级对抗里第几、一共几个班；这学期还没做对过题的班没有名次 */
+  rank: z.number().int().positive().nullable(),
+  battleSize: z.number().int().nonnegative(),
+  perCapita: z.number(),
+  /** 同年级在用的班（这学期做对过题）的人均；没有为 null */
+  gradeAvg: z.number().nullable(),
+  /** 中间那位同学做对几道 */
+  median: z.number(),
+  /** 这学期做对过至少 1 道的人数 */
+  solvedMembers: z.number().int().nonnegative(),
+  top10Avg: z.number(),
+  bottom10Avg: z.number(),
+  /** 人最多的那一档同分（至少 5 人才算「停在这」），没有为 null */
+  plateau: z.object({ solved: z.number().int(), count: z.number().int() }).nullable(),
+  /** 每个同学这学期做对几道，画分布点阵用 */
+  distribution: z.array(z.number().int().nonnegative()),
+  /** 这学期每周（周一起）人均新做对，和同年级在用的班平均比 */
+  weeks: z.array(
+    z.object({ weekStart: z.string(), perCapita: z.number(), gradeAvg: z.number().nullable() }),
+  ),
+  /** 要多关心的同学（这学期做对不到 3 道），只给老师；学生拿到的是 null */
+  care: z
+    .array(
+      z.object({
+        user: sampleUserSchema,
+        avatar: z.string().nullable(),
+        solved: z.number().int().nonnegative(),
+        submissions: z.number().int().nonnegative(),
+      }),
+    )
+    .nullable(),
+})
+
+export type ClassDetail = z.infer<typeof classDetailSchema>