diff --git a/apps/web/src/oj/problem/components/EditorToolbar.vue b/apps/web/src/oj/problem/components/EditorToolbar.vue
index f477e18..7802337 100644
--- a/apps/web/src/oj/problem/components/EditorToolbar.vue
+++ b/apps/web/src/oj/problem/components/EditorToolbar.vue
@@ -214,12 +214,22 @@ const copy = async () => {
   message[success ? "success" : "error"](`代码复制${success ? "成功" : "失败"}`)
 }
 
+// 重置会把编辑器里的代码换成模板、连本地草稿一起删掉，点错一下写了半节课的代码就没了，先问一句
+const dialog = useDialog()
 const reset = () => {
-  codeStore.setCode(
-    problem.value!.template[codeStore.code.language] || SOURCES[codeStore.code.language],
-  )
-  storage.remove(storageKey)
-  message.success("代码重置成功")
+  dialog.warning({
+    title: "重置代码",
+    content: "编辑器里的代码会换回题目给的模板，存着的草稿也会删掉。确定吗？",
+    positiveText: "重置",
+    negativeText: "再想想",
+    onPositiveClick: () => {
+      codeStore.setCode(
+        problem.value!.template[codeStore.code.language] || SOURCES[codeStore.code.language],
+      )
+      storage.remove(storageKey)
+      message.success("已换回模板，按 Ctrl+Z 可以撤回")
+    },
+  })
 }
 
 const changeLanguage = (v: LANGUAGE) => {
diff --git a/apps/web/src/oj/problem/components/ProblemContent.vue b/apps/web/src/oj/problem/components/ProblemContent.vue
index a2f3545..0931730 100644
--- a/apps/web/src/oj/problem/components/ProblemContent.vue
+++ b/apps/web/src/oj/problem/components/ProblemContent.vue
@@ -5,13 +5,12 @@ import { useProblemStore } from "oj/store/problem"
 import { DIFFICULTY } from "utils/constants"
 import { getTagColor } from "utils/functions"
 import { useSubmissionStore } from "oj/store/submission"
-import type { ProblemRow } from "utils/types"
 import Copy from "shared/components/Copy.vue"
 import { useDark } from "@vueuse/core"
 import { MdPreview } from "md-editor-v3"
 import "md-editor-v3/lib/preview.css"
-import { getSimilarProblems } from "oj/api"
 import SQLDataTable from "./SQLDataTable.vue"
+import SimilarProblems from "./SimilarProblems.vue"
 import { useFlowchartStore } from "oj/store/flowchart"
 import { useMyFlowchartStore } from "shared/store/myFlowchart"
 import { useUserStore } from "shared/store/user"
@@ -37,42 +36,9 @@ const sqlChangedTables = computed(() => {
   return exp && "changed_tables" in exp ? exp.changed_tables : []
 })
 
-const router = useRouter()
-
-// 相似题目推荐
-const similarProblems = ref<ProblemRow[]>([])
-const similarLoaded = ref(false)
-
-async function loadSimilarProblems() {
-  if (similarLoaded.value || !problem.value) return
-  // 比赛、题单里不推荐（理由见 problemPageContext 那张表）
-  if (!ctx.value.similar) return
-  try {
-    similarProblems.value = await getSimilarProblems(problem.value._id)
-  } catch {
-    similarProblems.value = []
-  }
-  similarLoaded.value = true
-}
-
-// 切换题目时重置相似推荐状态
-watch(
-  () => problem.value?._id,
-  () => {
-    similarProblems.value = []
-    similarLoaded.value = false
-  },
-)
-
-// AC 或失败次数 >= 3 时加载推荐
-watch(
-  () => [problem.value?._id, problem.value?.myStatus, problemStore.failCount],
-  ([, status, failCount]) => {
-    if (status === 0 || (failCount as number) >= 3) {
-      loadSimilarProblems()
-    }
-  },
-  { immediate: true },
+// 相似题推荐：做对了、或者错了 3 次以上才给（比赛、题单里不给，见 problemPageContext）
+const showSimilar = computed(
+  () => ctx.value.similar && (problem.value?.myStatus === 0 || problemStore.failCount >= 3),
 )
 
 /**
@@ -352,49 +318,7 @@ const astRequirements = computed(() => Object.entries(problem.value?.astRequirem
       />
     </div>
 
-    <!-- 相似题目推荐 -->
-    <div v-if="ctx.similar && similarProblems.length > 0">
-      <n-divider />
-      <h3 class="title">
-        <Icon icon="streamline-ultimate-color:like"></Icon>
-        相似题目推荐
-      </h3>
-      <n-list bordered>
-        <n-list-item v-for="sp in similarProblems" :key="sp._id">
-          <n-flex align="center" justify="space-between">
-            <n-flex align="center">
-              <n-tag size="small">{{ sp._id }}</n-tag>
-              <n-button
-                text
-                type="info"
-                @click="
-                  router.push({
-                    name: 'problem',
-                    params: { problemID: sp._id },
-                  })
-                "
-              >
-                {{ sp.title }}
-              </n-button>
-            </n-flex>
-            <!-- getSimilarProblems 已经过 toProblemRow，难度是中文，不是 Low/Mid/High -->
-            <n-tag
-              v-if="sp.difficulty"
-              size="small"
-              :type="
-                sp.difficulty === '简单'
-                  ? 'success'
-                  : sp.difficulty === '困难'
-                    ? 'error'
-                    : 'warning'
-              "
-            >
-              {{ sp.difficulty }}
-            </n-tag>
-          </n-flex>
-        </n-list-item>
-      </n-list>
-    </div>
+    <SimilarProblems v-if="showSimilar" title="相似题目推荐" />
   </div>
 </template>
 
diff --git a/apps/web/src/oj/problem/components/ResultPane.vue b/apps/web/src/oj/problem/components/ResultPane.vue
index 7c5ccf5..b2e895e 100644
--- a/apps/web/src/oj/problem/components/ResultPane.vue
+++ b/apps/web/src/oj/problem/components/ResultPane.vue
@@ -23,7 +23,8 @@ const FlowchartResult = defineAsyncComponent(() => import("./FlowchartResult.vue
 const PeerLatest = defineAsyncComponent(() => import("./PeerLatest.vue"))
 
 const submissionStore = useSubmissionStore()
-const { submission, syntaxErrorInfo, resultSegment } = storeToRefs(submissionStore)
+const { submission, syntaxErrorInfo, resultSegment, formattedBeforeSubmit } =
+  storeToRefs(submissionStore)
 const { problem } = storeToRefs(useProblemStore())
 const codeStore = useCodeStore()
 
@@ -55,7 +56,12 @@ const canTrial = computed(() => {
         <n-alert type="warning" title="代码有语法错误，还没有提交" />
         <PythonErrorExplain :err-info="syntaxErrorInfo" />
       </n-flex>
-      <SubmissionResult v-else-if="submission" :submission="submission" />
+      <template v-else-if="submission">
+        <p v-if="formattedBeforeSubmit" class="formatted">
+          提交之前自动整理了代码格式（缩进、空格），编辑器里的代码也跟着变了，按 Ctrl+Z 能撤回
+        </p>
+        <SubmissionResult :submission="submission" />
+      </template>
       <PeerLatest v-else-if="teacherCollab" />
       <n-empty
         v-else
@@ -79,6 +85,12 @@ const canTrial = computed(() => {
   margin-bottom: 14px;
 }
 
+.formatted {
+  margin: 0 0 10px;
+  font-size: 13px;
+  opacity: 0.7;
+}
+
 .empty {
   margin-top: 48px;
 }
diff --git a/apps/web/src/oj/problem/components/SimilarProblems.vue b/apps/web/src/oj/problem/components/SimilarProblems.vue
new file mode 100644
index 0000000..a6b9e0b
--- /dev/null
+++ b/apps/web/src/oj/problem/components/SimilarProblems.vue
@@ -0,0 +1,97 @@
+<script lang="ts">
+import type { ProblemRow } from "utils/types"
+
+/**
+ * 同一道题两处（题面末尾、结果页签）都挂着时只拉一次。放在模块级：写在 setup 里就成了
+ * 每个实例各一份
+ */
+const cache = new Map<string, Promise<ProblemRow[]>>()
+</script>
+
+<script setup lang="ts">
+import { storeToRefs } from "pinia"
+import { getSimilarProblems } from "oj/api"
+import { useProblemStore } from "oj/store/problem"
+
+/**
+ * 相似题推荐。题面末尾（做对了、或者错了 3 次以上）和结果页签（不在课堂里的题做对之后）
+ * 两处用：原来只在题面最底下，学生交完不会再滚回去看。什么时候出现由调用方的 v-if 决定。
+ */
+const props = defineProps<{ title: string }>()
+
+const { problem } = storeToRefs(useProblemStore())
+const list = ref<ProblemRow[]>([])
+
+watch(
+  () => problem.value?._id,
+  async (id) => {
+    list.value = []
+    if (!id) return
+    if (!cache.has(id))
+      cache.set(
+        id,
+        getSimilarProblems(id).catch(() => []),
+      )
+    const rows = await cache.get(id)!
+    if (problem.value?._id === id) list.value = rows
+  },
+  { immediate: true },
+)
+
+// getSimilarProblems 已经过 toProblemRow，难度是中文，不是 Low/Mid/High
+function difficultyType(difficulty: string) {
+  if (difficulty === "简单") return "success"
+  if (difficulty === "困难") return "error"
+  return "warning"
+}
+</script>
+
+<template>
+  <section v-if="list.length" class="similar">
+    <h3 class="title">{{ props.title }}</h3>
+    <n-list bordered>
+      <n-list-item v-for="sp in list" :key="sp._id">
+        <n-flex align="center" justify="space-between" :wrap="false">
+          <router-link :to="{ name: 'problem', params: { problemID: sp._id } }" class="link">
+            <n-tag size="small" :bordered="false">{{ sp._id }}</n-tag>
+            <span class="name">{{ sp.title }}</span>
+          </router-link>
+          <n-tag v-if="sp.difficulty" size="small" :type="difficultyType(sp.difficulty)">
+            {{ sp.difficulty }}
+          </n-tag>
+        </n-flex>
+      </n-list-item>
+    </n-list>
+  </section>
+</template>
+
+<style scoped>
+.similar {
+  margin-top: 20px;
+}
+
+.title {
+  font-size: 16px;
+  font-weight: 600;
+  margin: 0 0 8px;
+}
+
+.link {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+  color: inherit;
+  text-decoration: none;
+}
+
+.link:hover .name {
+  text-decoration: underline;
+}
+
+.name {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+</style>
diff --git a/apps/web/src/oj/problem/components/SubmissionResult.vue b/apps/web/src/oj/problem/components/SubmissionResult.vue
index 6e3c448..adf2fd2 100644
--- a/apps/web/src/oj/problem/components/SubmissionResult.vue
+++ b/apps/web/src/oj/problem/components/SubmissionResult.vue
@@ -19,6 +19,8 @@ import PythonErrorExplain from "./PythonErrorExplain.vue"
 import RuntimeErrorExplain from "./RuntimeErrorExplain.vue"
 import WrongAnswerExplain from "./WrongAnswerExplain.vue"
 import LessonNext from "./LessonNext.vue"
+import SimilarProblems from "./SimilarProblems.vue"
+import { useLessonStore } from "oj/store/lesson"
 import { useProblemPageContext } from "../composables/problemPageContext"
 import { MdPreview } from "md-editor-v3"
 import "md-editor-v3/lib/preview.css"
@@ -98,6 +100,20 @@ const showLessonNext = computed(
     !props.peer && props.submission?.result === SubmissionStatus.accepted && ctx.value.lessonNext,
 )
 
+/**
+ * 通过了、但这道题不在这节课里（没有「下一题」可给）：给几道相似题接着练。
+ * 原来相似题只在题面最底下，交完不会有人再滚回去看
+ */
+const lessonStore = useLessonStore()
+const showSimilar = computed(
+  () =>
+    !props.peer &&
+    props.submission?.result === SubmissionStatus.accepted &&
+    ctx.value.similar &&
+    !!problemStore.problem &&
+    !lessonStore.includes(problemStore.problem._id),
+)
+
 const msg = computed(() => {
   if (!props.submission) return ""
   // 走 PythonErrorExplain / RuntimeErrorExplain 那两张中文卡片
@@ -216,6 +232,7 @@ const columns: DataTableColumn<JudgeCaseResult>[] = [
       v-if="showLessonNext && problemStore.problem"
       :problem-display-id="problemStore.problem._id"
     />
+    <SimilarProblems v-if="showSimilar" title="再练几道相似的" />
     <n-flex
       vertical
       v-if="
diff --git a/apps/web/src/oj/problem/components/SubmitCode.vue b/apps/web/src/oj/problem/components/SubmitCode.vue
index 5a876c1..3e0d102 100644
--- a/apps/web/src/oj/problem/components/SubmitCode.vue
+++ b/apps/web/src/oj/problem/components/SubmitCode.vue
@@ -5,6 +5,7 @@ import { useSubmissionStore } from "oj/store/submission"
 import { getSubmitButtonState } from "./submitButtonState"
 import { useBreakpoints } from "shared/composables/breakpoints"
 import { useUserStore } from "shared/store/user"
+import { SubmissionStatus } from "utils/constants"
 
 /**
  * 提交按钮。只把点击交给 store：提交的状态在 submission store，结果显示在左栏的
@@ -33,6 +34,14 @@ const buttonState = computed(() =>
   }),
 )
 
+/**
+ * 这道题刚交对了：「提交」降成描边按钮，让结果页签里的「下一题」是唯一的主按钮
+ * （设计文档 5.4）。改了代码想再交一次照样能交
+ */
+const justAccepted = computed(
+  () => submissionStore.submission?.result === SubmissionStatus.accepted,
+)
+
 function submit() {
   if (buttonState.value.disabled) return
   submissionStore.submit({
@@ -46,7 +55,7 @@ function submit() {
   <n-button
     :size="props.size ?? (isDesktop ? 'medium' : 'small')"
     :block="props.block"
-    type="primary"
+    :type="justAccepted ? 'default' : 'primary'"
     :disabled="buttonState.disabled"
     @click="submit"
   >
diff --git a/apps/web/src/oj/problem/utils/wrongAnswer.ts b/apps/web/src/oj/problem/utils/wrongAnswer.ts
index 8c2bbed..eca877a 100644
--- a/apps/web/src/oj/problem/utils/wrongAnswer.ts
+++ b/apps/web/src/oj/problem/utils/wrongAnswer.ts
@@ -147,10 +147,40 @@ export function explainDiff(
     case "values":
       return "输出的格式对了，但算出来的数不对。拿这个例子的输入，自己一步一步算一遍，看看程序在哪一步和你想的不一样。"
     case "other":
-      return "对照一下你的输出和正确输出，找找从哪里开始不一样。"
+      return otherHint(check)
   }
 }
 
+/** 放进一句话里的值：太长的截断，免得一句提示撑满一屏 */
+function quote(text: string, max = 24) {
+  const flat = text.trim()
+  return `「${flat.length > max ? `${flat.slice(0, max)}…` : flat}」`
+}
+
+/**
+ * 「其他」：格式和内容都不一样（占样例错误的 44%）。原来只说「对照一下，找找从哪里开始
+ * 不一样」，对 D / E 这种整个值不同的情况没用 —— 学生看得出不一样，看不出为什么。
+ * 改成把具体的值说出来，再告诉他拿这个例子的输入去走一遍程序（设计文档第 6 节）。
+ */
+function otherHint(check: SampleCheck) {
+  const expected = (check.expected ?? "").replace(/\s+$/, "")
+  const output = (check.output ?? "").replace(/\s+$/, "")
+  const no = (check.index ?? 0) + 1
+  const input = (check.input ?? "").trim()
+  const walk =
+    input && !input.includes("\n") && input.length <= 24
+      ? `拿例子 ${no} 的输入${quote(input)}，一行一行走一遍你的程序，看它走进了哪个分支、算出了什么。`
+      : `拿例子 ${no} 的输入，一行一行走一遍你的程序，看它走进了哪个分支、算出了什么。`
+  if (!expected.includes("\n") && !output.includes("\n")) {
+    return `你的程序输出了${quote(output)}，正确的是${quote(expected)}。${walk}`
+  }
+  const line = firstDifferentLine(expected, output)
+  const want = expected.split("\n")[line] ?? ""
+  const got = output.split("\n")[line]
+  const gotText = got === undefined ? "什么都没有" : quote(got)
+  return `从第 ${line + 1} 行开始不一样：正确的是${quote(want)}，你输出的是${gotText}。${walk}`
+}
+
 /** 第一处不一样的行号，0 起；完全一样（只差结尾空白）时为 -1 */
 export function firstDifferentLine(expected: string, output: string) {
   const e = expected.replace(/\s+$/, "").split("\n")
diff --git a/apps/web/src/oj/store/submission.ts b/apps/web/src/oj/store/submission.ts
index 0a36e18..ee8009e 100644
--- a/apps/web/src/oj/store/submission.ts
+++ b/apps/web/src/oj/store/submission.ts
@@ -71,6 +71,12 @@ export const useSubmissionStore = defineStore("submission", () => {
    */
   const syntaxErrorInfo = ref("")
 
+  /**
+   * 这次提交之前自动排版改了代码。排版会直接改掉编辑器里的代码（缩进、空格、换行），
+   * 学生交完发现代码「变了样」却不知道为什么 —— 结果页签里提一句
+   */
+  const formattedBeforeSubmit = ref(false)
+
   const { start: startCooldown, isPending: isCooldown } = useTimeout(5000, {
     controls: true,
     immediate: false,
@@ -84,6 +90,7 @@ export const useSubmissionStore = defineStore("submission", () => {
     const problem = problemStore.problem
     if (!problem) return
     syntaxErrorInfo.value = ""
+    formattedBeforeSubmit.value = false
 
     // 0. 提交前自动格式化（Python 用 ruff，C/C++ 用 clang-format，SQL 用 sqlparse）。
     //    Python 在格式化之前先由服务端的 CPython 查一遍语法，有错就不提交
@@ -95,7 +102,10 @@ export const useSubmissionStore = defineStore("submission", () => {
           code: codeStore.code.value,
           language: formatLang,
         })
-        codeStore.setCode(res.code)
+        if (res.code !== codeStore.code.value) {
+          codeStore.setCode(res.code)
+          formattedBeforeSubmit.value = true
+        }
       } catch (e) {
         if (errorCode(e) === "syntax-error") {
           // 仅 Python 会出现：message 是 CPython 的报错原文，交给 PythonErrorExplain 翻译
@@ -151,6 +161,7 @@ export const useSubmissionStore = defineStore("submission", () => {
    */
   function reset() {
     syntaxErrorInfo.value = ""
+    formattedBeforeSubmit.value = false
     resultSegment.value = "submit"
     monitor.reset()
     hint.clearHint()
@@ -183,6 +194,7 @@ export const useSubmissionStore = defineStore("submission", () => {
     isFormatting,
     isSubmittingRequest,
     syntaxErrorInfo,
+    formattedBeforeSubmit,
     isCooldown,
     submit,
     reset,
diff --git a/apps/web/src/shared/components/AchievementToast.vue b/apps/web/src/shared/components/AchievementToast.vue
index 1d83dc0..ab64c64 100644
--- a/apps/web/src/shared/components/AchievementToast.vue
+++ b/apps/web/src/shared/components/AchievementToast.vue
@@ -59,8 +59,9 @@ onUnmounted(() => {
 <style scoped>
 .toast {
   position: fixed;
+  /* 右上角、顶栏下面。原来在右下角，题目页上正好和结果、点评弹窗叠在一起 */
   right: 24px;
-  bottom: 24px;
+  top: 72px;
   z-index: 3000;
   display: flex;
   gap: 12px;
diff --git a/packages/contract/src/ai.ts b/packages/contract/src/ai.ts
index d31b90d..33533b7 100644
--- a/packages/contract/src/ai.ts
+++ b/packages/contract/src/ai.ts
@@ -162,7 +162,8 @@ export const HINT_LEVEL_COMPILE = -1
 export function hintLevelLabel(level: number) {
   if (level === HINT_LEVEL_COMPILE) return "编译错误"
   const item = HINT_LEVELS.find((entry) => entry.level === level)
-  return item ? `L${item.level} ${item.name}` : `L${level}`
+  // 给学生看的，从 1 数起、不写「L0」：学生不知道 L 是什么，也不会从 0 数
+  return item ? `第 ${item.level + 1} 档 · ${item.name}` : `第 ${level + 1} 档`
 }
 
 /**