diff --git a/apps/web/src/oj/announcement/components/TitleWithTag.vue b/apps/web/src/oj/announcement/components/TitleWithTag.vue
deleted file mode 100644
index 0a8a845..0000000
--- a/apps/web/src/oj/announcement/components/TitleWithTag.vue
+++ /dev/null
@@ -1,14 +0,0 @@
-<template>
-  <n-flex align="center" :size="8" :wrap="false">
-    <n-tag type="error" size="small" v-if="top">置顶</n-tag>
-    <span>{{ title }}</span>
-  </n-flex>
-</template>
-<script setup lang="ts">
-interface Props {
-  top: boolean
-  title: string
-}
-
-defineProps<Props>()
-</script>
diff --git a/apps/web/src/oj/contest/detail.vue b/apps/web/src/oj/contest/detail.vue
index 6a1d2dc..be0da74 100644
--- a/apps/web/src/oj/contest/detail.vue
+++ b/apps/web/src/oj/contest/detail.vue
@@ -3,6 +3,8 @@ import { useThemeVars } from "naive-ui"
 import { useTone } from "oj/submission/composables/tone"
 import { ContestStatus } from "utils/constants"
 import { parseTime, secondsToDuration } from "utils/functions"
+import NotFound from "shared/components/NotFound.vue"
+import { errorCode } from "utils/api"
 import { useContestStore } from "../store/contest"
 import ContestBadge from "./components/ContestBadge.vue"
 import ContestInfo from "./components/ContestInfo.vue"
@@ -34,18 +36,27 @@ async function check() {
   }
 }
 
+/** 拉比赛失败：原来没接，链接不对就是一整页空白 */
+const failure = ref<null | "missing" | "failed">(null)
+
+async function load() {
+  failure.value = null
+  try {
+    await contestStore.init(props.contestID)
+  } catch (err) {
+    if (contestStore.contest) return
+    failure.value = errorCode(err) === "contest-not-found" ? "missing" : "failed"
+  }
+}
+
 watch(
   () => contestStore.contestStatus,
   (nv, ov) => {
-    if (nv === ContestStatus.underway && ov == ContestStatus.not_started) {
-      contestStore.init(props.contestID)
-    }
+    if (nv === ContestStatus.underway && ov == ContestStatus.not_started) load()
   },
 )
 
-onMounted(() => {
-  contestStore.init(props.contestID)
-})
+onMounted(load)
 
 onBeforeUnmount(contestStore.clear)
 
@@ -95,7 +106,17 @@ const to = (name: string) => ({ name, params: { contestID: props.contestID } })
 </script>
 
 <template>
-  <div v-if="contest" class="contest-page">
+  <NotFound
+    v-if="failure === 'missing'"
+    title="这场比赛不存在"
+    hint="可能是链接复制错了，或者这场比赛还没公开"
+    to="/contest"
+    to-label="去比赛列表"
+  />
+  <NotFound v-else-if="failure === 'failed'" icon="ph:wifi-slash" title="比赛没拉下来">
+    <n-button type="primary" @click="load()">再试一次</n-button>
+  </NotFound>
+  <div v-else-if="contest" class="contest-page">
     <header class="bar">
       <ContestBadge :status="status" />
       <h2 class="title">{{ contest.title }}</h2>
diff --git a/apps/web/src/oj/problem/detail.vue b/apps/web/src/oj/problem/detail.vue
index 3758e1c..2d250c6 100644
--- a/apps/web/src/oj/problem/detail.vue
+++ b/apps/web/src/oj/problem/detail.vue
@@ -11,6 +11,7 @@ import { useSubmissionStore } from "oj/store/submission"
 import { useFlowchartStore } from "oj/store/flowchart"
 import { useCollabStore } from "shared/store/collab"
 import type { RouteLocationNormalized } from "vue-router"
+import NotFound from "shared/components/NotFound.vue"
 // 判完之后该发生的事（烟花、点评、回题单）。静态引入：它得在第一次判完之前就挂好
 import SubmissionEffects from "./components/SubmissionEffects.vue"
 import ResultTabLabel from "./components/ResultTabLabel.vue"
@@ -40,9 +41,10 @@ interface Props {
   problemSetId?: string
 }
 
-const { problemID, contestID = "" } = defineProps<Props>()
+const { problemID, contestID = "", problemSetId = "" } = defineProps<Props>()
 
-const errMsg = ref("无数据")
+/** 拉题面失败的原因：null 是还在拉（或拉到了），别的就整页换成 NotFound */
+const failure = ref<null | "missing" | "not-started" | "failed">(null)
 const route = useRoute()
 const router = useRouter()
 
@@ -226,6 +228,7 @@ async function init() {
   // 并行预取右侧编辑器 chunk（CodeMirror ~370K+），
   // 避免等 getProblem 返回后才串行下载，编辑器才迟迟出现
   loadProblemEditor()
+  failure.value = null
   try {
     const res = await getProblem(problemID, contestID)
     if (mine !== initSeq) return
@@ -233,12 +236,25 @@ async function init() {
   } catch (err) {
     if (mine !== initSeq) return
     problem.value = null
-    if (errorCode(err) === "contest-not-started") {
-      errMsg.value = "比赛还没有开始"
-    }
+    const code = errorCode(err)
+    failure.value =
+      code === "contest-not-started"
+        ? "not-started"
+        : code === "problem-not-found"
+          ? "missing"
+          : "failed"
   }
 }
 onMounted(init)
+
+/** 题不存在时回哪：比赛里回比赛，题单里回题单，否则回题目列表 */
+const backTo = computed(() =>
+  contestID
+    ? { to: `/contest/${contestID}`, toLabel: "回到比赛" }
+    : problemSetId
+      ? { to: `/problemset/${problemSetId}`, toLabel: "回到题单" }
+      : { to: "/problem", toLabel: "去题目列表" },
+)
 watch(() => problemID, init)
 
 // 题目详情里的 myStatus / myFailedCount 是按当前用户算的，而登录不重新挂载这个页面 ——
@@ -262,7 +278,7 @@ onBeforeUnmount(() => {
   // 流程图那边同理，还在评的那次不再跟（照常评完落库）
   useFlowchartStore().reset()
   problem.value = null
-  errMsg.value = "无数据"
+  failure.value = null
   myFlowchartStore.hide()
 })
 </script>
@@ -372,7 +388,23 @@ onBeforeUnmount(() => {
       <MobileActionBar />
     </div>
   </template>
-  <n-empty v-else :description="errMsg"></n-empty>
+  <NotFound
+    v-else-if="failure === 'not-started'"
+    icon="ph:clock"
+    title="比赛还没有开始"
+    hint="开始以后才能看题"
+    :to="`/contest/${contestID}`"
+    to-label="回到比赛"
+  />
+  <NotFound v-else-if="failure === 'failed'" icon="ph:wifi-slash" title="题目没拉下来">
+    <n-button type="primary" @click="init()">再试一次</n-button>
+  </NotFound>
+  <NotFound
+    v-else-if="failure === 'missing'"
+    title="这道题不存在"
+    hint="可能是题号打错了，或者这道题还没公开"
+    v-bind="backTo"
+  />
 </template>
 
 <style scoped>
diff --git a/apps/web/src/oj/problemset/detail.vue b/apps/web/src/oj/problemset/detail.vue
index 6d6b5d3..5830be9 100644
--- a/apps/web/src/oj/problemset/detail.vue
+++ b/apps/web/src/oj/problemset/detail.vue
@@ -9,6 +9,7 @@ import type { ProblemSet, ProblemSetProblem } from "utils/types"
 import { useAuthModalStore } from "shared/store/authModal"
 import { useUserStore } from "shared/store/user"
 import { useFireworks } from "../problem/composables/useFireworks"
+import NotFound from "shared/components/NotFound.vue"
 import BadgeLadder from "./components/BadgeLadder.vue"
 import ClassView from "./components/ClassView.vue"
 
@@ -133,16 +134,13 @@ const purple = { color: "#5b3fa8", background: "rgba(122, 95, 208, 0.12)" }
 </script>
 
 <template>
-  <n-result
+  <NotFound
     v-if="missing"
-    status="404"
-    title="题单不存在"
-    description="可能还没公开，或者已经删掉了"
-  >
-    <template #footer>
-      <n-button @click="router.push({ name: 'problemsets' })">回到题单列表</n-button>
-    </template>
-  </n-result>
+    title="这个题单不存在"
+    hint="可能还没公开，或者已经删掉了"
+    to="/problemset"
+    to-label="回到题单列表"
+  />
 
   <div v-else-if="set" class="page oj-page">
     <section class="band" :class="{ done: progress?.isCompleted }">
diff --git a/apps/web/src/routes.ts b/apps/web/src/routes.ts
index 067e0c1..8dda70a 100644
--- a/apps/web/src/routes.ts
+++ b/apps/web/src/routes.ts
@@ -146,6 +146,14 @@ export const ojs: RouteRecordRaw = {
       name: "problemset problem",
       meta: { requiresAuth: true },
     },
+    // 兜底：没有它，打错地址是一整页空白，连顶栏都没有。vue-router 按路径具体程度排序，
+    // 不按注册顺序，所以它吃不掉别的路由；/admin 下打错的也落到这里
+    {
+      path: ":pathMatch(.*)*",
+      name: "not found",
+      component: () => import("shared/components/NotFound.vue"),
+      props: { title: "这个页面不存在", hint: "可能是地址打错了，或者这个页面已经下线" },
+    },
   ],
 }
 
diff --git a/apps/web/src/shared/components/NotFound.vue b/apps/web/src/shared/components/NotFound.vue
new file mode 100644
index 0000000..f76ddcb
--- /dev/null
+++ b/apps/web/src/shared/components/NotFound.vue
@@ -0,0 +1,71 @@
+<script setup lang="ts">
+import { Icon } from "@iconify/vue"
+import { useThemeVars } from "naive-ui"
+import type { RouteLocationRaw } from "vue-router"
+
+/**
+ * 「找不到」的整页提示：地址打错、题目 / 比赛 / 题单不存在或没公开、比赛还没开始。
+ * 原来各页各写各的 —— 打错地址是一整页空白、题号不对只有一个「无数据」，学生看不出出了什么事。
+ * 样子跟提交详情的「这条提交不存在」一致：图标、一句话、一句为什么、一个回去的按钮。
+ */
+const props = withDefaults(
+  defineProps<{
+    title: string
+    hint?: string
+    icon?: string
+    to?: RouteLocationRaw
+    toLabel?: string
+  }>(),
+  { hint: "", icon: "ph:magnifying-glass", to: "/", toLabel: "回首页" },
+)
+
+const theme = useThemeVars()
+const router = useRouter()
+</script>
+
+<template>
+  <div class="not-found">
+    <Icon :icon="props.icon" :width="40" class="icon" />
+    <span class="title">{{ props.title }}</span>
+    <span v-if="props.hint" class="hint">{{ props.hint }}</span>
+    <div class="actions">
+      <slot>
+        <n-button type="primary" @click="router.push(props.to)">{{ props.toLabel }}</n-button>
+      </slot>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.not-found {
+  min-height: 360px;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 10px;
+  padding: 48px 16px;
+  text-align: center;
+}
+
+.icon {
+  color: v-bind("theme.textColor3");
+  opacity: 0.7;
+}
+
+.title {
+  font-size: 18px;
+  font-weight: 600;
+}
+
+.hint {
+  font-size: var(--oj-fs-sec);
+  color: v-bind("theme.textColor3");
+}
+
+.actions {
+  display: flex;
+  gap: 10px;
+  margin-top: 8px;
+}
+</style>