diff --git a/src/App.vue b/src/App.vue
index 5621c7f..c1e4a9d 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -12,6 +12,7 @@ import BschIframe from "@/components/BschIframe.vue";
 import SearchPanel from "@/components/SearchPanel.vue";
 import UserInfoModal from "@/components/UserInfoModal.vue";
 import LightPageModal from "@/components/LightPageModal.vue";
+import ThemePreview from "@/views/ThemePreview.vue";
 
 import BaseApi from "@/api/BaseApi";
 import { BschIframeType, IframePageParmas, RoleInfo, StateEnum } from "./types";
@@ -60,6 +61,7 @@ mittBus.on("openBschIframePage", async (params: IframePageParmas) => {
     try {
         const [r1, r2] = await Promise.all([p1, p2]);
         store.$state.userInfo = userinfo;
+        loadSchThemeDefault();
         if (r1.length == 0) {
             store.$state.userRoleList = [
                 {
@@ -86,6 +88,21 @@ mittBus.on("openBschIframePage", async (params: IframePageParmas) => {
     console.timeEnd("init");
 })();
 
+/** 拉学校默认主题档写键（异步尽力而为：失败/404/空 → 不写、不报错、不阻塞登录流程） */
+function loadSchThemeDefault() {
+    BaseApi.getSchTheme()
+        .then((res: any) => {
+            if (res && res.themeState) {
+                try {
+                    localStorage.setItem("yh-theme-sch-default", res.themeState);
+                } catch (e) {
+                    /* 隐私模式写失败静默 */
+                }
+            }
+        })
+        .catch(() => undefined);
+}
+
 /**切换角色 */
 async function switchRole() {
     await loadUserMenuBarList();
@@ -113,8 +130,9 @@ async function loadUserMenuBarList() {
     } else {
         findIndex = menuList.findIndex(x => x.url === route.path);
     }
-    // /msg、/settings 由后台「边栏设置」配置后即进入菜单表；未配置时也允许直达/刷新，不被弹回桌面
-    if (findIndex === -1 && !["/msg", "/settings"].includes(route.path)) router.push({ name: "index" });
+    // /msg、/settings 由后台「边栏设置」配置后即进入菜单表；未配置时也允许直达/刷新，不被弹回桌面。
+    // /theme-preview 同理（预览页按 URL 参数挂档，不依赖菜单表与登录态）
+    if (findIndex === -1 && !["/msg", "/settings", "/theme-preview"].includes(route.path)) router.push({ name: "index" });
 }
 
 const getRouterKey: (route: any) => string = route => {
@@ -128,7 +146,11 @@ const mainStyle = computed(() => `background-image: url(${store.getCurWallPaperU
 </script>
 
 <template>
+    <!-- 主题预览页（主题设置 2026-09-30）：顶层独立分支——不进桌面框架（无左栏/Header/壁纸）、
+         不依赖登录态与 isRouterAlive 门控（未登录直开也不白屏）；仅在该 document 内动态引通道 init -->
+    <ThemePreview v-if="route.path === '/theme-preview'" />
     <div
+        v-else
         :class="['app-desktop  app-desktop__animation', !menuVisible ? 'app-desktop__full' : '']"
         :style="mainStyle"
         v-show="StateType > StateEnum.Loading"
diff --git a/src/api/BaseApi.ts b/src/api/BaseApi.ts
index 5c63700..84cc6e7 100644
--- a/src/api/BaseApi.ts
+++ b/src/api/BaseApi.ts
@@ -181,6 +181,29 @@ class Base extends Abstract {
         return this.postRequest({ url, params: { logoUrl } });
     }
 
+    // ===== 学校默认主题档（主题设置 2026-09-30；后端契约见 SchSettingsController）=====
+
+    /**
+     * 读本校默认主题档（已登录可读）：{themeState: "<ThemeState JSON>" | null}——
+     * null 表示未配置（前端"不写键、不报错"），登录后调一次写 localStorage["yh-theme-sch-default"]
+     */
+    getSchTheme() {
+        const url = path + "/schTheme";
+        return this.getRequest<{ themeState: string | null; schId: number }>({ url });
+    }
+
+    /** 保存本校默认主题档（仅学校管理员）：themeState 为整份 ThemeState JSON 字符串 */
+    saveSchThemeState(themeState: string) {
+        const url = path + "/saveSchThemeState";
+        return this.postRequest({ url, params: { themeState } });
+    }
+
+    /** 清空本校默认主题档（仅学校管理员；置空后读侧返回 null） */
+    clearSchTheme() {
+        const url = path + "/clearSchTheme";
+        return this.postRequest({ url });
+    }
+
     savUserRole(info: any) {
         const url = path + "/user/savUserRole";
         return this.postRequest({ url, data: info as any });
diff --git a/src/router/routes.ts b/src/router/routes.ts
index b247a5b..5f07ed3 100644
--- a/src/router/routes.ts
+++ b/src/router/routes.ts
@@ -83,5 +83,14 @@ const routes: RouteRecordRaw[] = [
         component: () => import("@/views/Settings.vue"),
         meta: { title: "设置" },
     },
+    {
+        // 主题预览页（主题设置 2026-09-30）：实际渲染走 App.vue 顶层条件分支（不进桌面框架，未登录直开不白屏）。
+        // 此处登记是为 URL 匹配合法（免 no-match 告警）；若后续引入全局路由守卫，必须把本路由列入
+        // 免登录/免初始化白名单——预览页按 URL 覆盖参数挂档，不依赖登录态（YschTheme 方案 §3.4/§4 S2.6）。
+        path: "/theme-preview",
+        name: "ThemePreview",
+        component: () => import("@/views/ThemePreview.vue"),
+        meta: { title: "主题预览" },
+    },
 ];
 export default routes;
diff --git a/src/utils/theme.ts b/src/utils/theme.ts
new file mode 100644
index 0000000..fbc7ceb
--- /dev/null
+++ b/src/utils/theme.ts
@@ -0,0 +1,151 @@
+/**
+ * 本文件由 YschTheme scripts/gen-theme.mjs 从 assets-src/pc/theme-core.js 生成（版本 20260930-1248-4e12e6d），勿手改。
+ * 分发方式：YschTheme `npm run sync` 拷进各端 src/utils/theme.ts（与 ThemeSwitcher.vue 配套，MD5 对齐报告）。
+ * 运行时档位类名由 /static/js/yh-theme-init.js 在 <head> 内先行挂好，本模块只负责读写与切换。
+ */
+export type ThemeName = "blue" | "ocean" | "ink" | "violet" | "teal";
+
+/** 定稿默认档：blue + side-deep + grad-on + 侧栏跟随（D1 拍板 deep） */
+export interface ThemeState {
+  theme: ThemeName;
+  /** 侧栏深色（false=浅色档） */
+  sideDeep: boolean;
+  /** 顶栏渐变（联动侧栏竖向渐变） */
+  gradOn: boolean;
+  /** 侧栏颜色跟随顶栏品牌色（false=中性灰 side-plain） */
+  sideFollow: boolean;
+}
+
+interface StorageLike {
+  getItem(k: string): string | null;
+  setItem(k: string, v: string): void;
+}
+
+export const THEME_NAMES: readonly ThemeName[] = ["blue", "ocean", "ink", "violet", "teal"];
+
+export const THEME_STORAGE_KEY = "yh-theme";
+
+/* 学校默认档存储键（UserHome 登录时写入；值格式与 yh-theme 完全相同，仅无"用户自选"语义） */
+export const SCHOOL_DEFAULT_STORAGE_KEY = "yh-theme-sch-default";
+
+export const DEFAULT_THEME_STATE: ThemeState = {
+  theme: "blue",
+  sideDeep: true,
+  gradOn: true,
+  sideFollow: true
+};
+
+/** 宽松解析：任一字段非法/缺失即回退默认档（脏数据不阻塞启动） */
+export function parseThemeState(raw: string | null): ThemeState {
+  if (!raw) return { ...DEFAULT_THEME_STATE };
+  try {
+    const o = JSON.parse(raw);
+    if (!o || typeof o !== "object") return { ...DEFAULT_THEME_STATE };
+    return {
+      theme: THEME_NAMES.includes(o.theme) ? o.theme : DEFAULT_THEME_STATE.theme,
+      sideDeep: typeof o.sideDeep === "boolean" ? o.sideDeep : DEFAULT_THEME_STATE.sideDeep,
+      gradOn: typeof o.gradOn === "boolean" ? o.gradOn : DEFAULT_THEME_STATE.gradOn,
+      sideFollow: typeof o.sideFollow === "boolean" ? o.sideFollow : DEFAULT_THEME_STATE.sideFollow
+    };
+  } catch {
+    return { ...DEFAULT_THEME_STATE };
+  }
+}
+
+/** 严格读取：四字段全部合法才返回状态，否则 null（合成链"值非法→回落下一级"用；用户键仍走宽松解析保现状） */
+function readThemeStateOrNull(raw: string | null): ThemeState | null {
+  if (!raw) return null;
+  try {
+    const o = JSON.parse(raw);
+    if (!o || typeof o !== "object") return null;
+    if (!THEME_NAMES.includes(o.theme)) return null;
+    if (typeof o.sideDeep !== "boolean" || typeof o.gradOn !== "boolean" || typeof o.sideFollow !== "boolean") return null;
+    return { theme: o.theme, sideDeep: o.sideDeep, gradOn: o.gradOn, sideFollow: o.sideFollow };
+  } catch {
+    return null;
+  }
+}
+
+/** URL 覆盖参数（?yh-theme= / ?yh-side=deep|light / ?yh-grad=on|off）：仅预览/排障用，
+    非法值忽略（对应字段不覆盖），且只影响"读哪一档"、绝不写回 localStorage。 */
+function readThemeOverrides(): { theme?: ThemeName; sideDeep?: boolean; gradOn?: boolean } | null {
+  let out = null;
+  try {
+    const search = (globalThis.location && globalThis.location.search) || "";
+    const get = (name) => {
+      const m = new RegExp("[?&]" + name + "=([^&]*)").exec(search);
+      return m ? decodeURIComponent(m[1]) : null;
+    };
+    const t = get("yh-theme");
+    if (t && THEME_NAMES.includes(t)) {
+      out = out || {};
+      out.theme = t;
+    }
+    const s = get("yh-side");
+    if (s === "deep" || s === "light") {
+      out = out || {};
+      out.sideDeep = s === "deep";
+    }
+    const g = get("yh-grad");
+    if (g === "on" || g === "off") {
+      out = out || {};
+      out.gradOn = g === "on";
+    }
+  } catch {
+    /* 无 location 环境（测试/SSR）：无覆盖 */
+  }
+  return out;
+}
+
+/**
+ * 生效档合成（唯一实现，init 启动段与 UserHome theme.ts 共用）：
+ *   URL 覆盖 > localStorage["yh-theme"]（用户自选，存在即用——宽松修补，与历史行为一致）
+ *   > localStorage["yh-theme-sch-default"]（学校默认，整体合法才生效）
+ *   > DEFAULT_THEME_STATE。
+ * 键不存在/解析失败/值非法均静默回落，不报错不阻塞首帧。
+ */
+export function resolveEffectiveThemeState(storage: StorageLike | undefined = globalThis.localStorage): ThemeState {
+  let state = null;
+  if (storage) {
+    const userRaw = storage.getItem(THEME_STORAGE_KEY);
+    if (userRaw) state = parseThemeState(userRaw);
+    if (!state) state = readThemeStateOrNull(storage.getItem(SCHOOL_DEFAULT_STORAGE_KEY));
+  }
+  if (!state) state = { ...DEFAULT_THEME_STATE };
+  const ov = readThemeOverrides();
+  if (ov) {
+    if (ov.theme) state = { ...state, theme: ov.theme };
+    if (ov.sideDeep != null) state = { ...state, sideDeep: ov.sideDeep };
+    if (ov.gradOn != null) state = { ...state, gradOn: ov.gradOn };
+  }
+  return state;
+}
+
+export function loadThemeState(storage: StorageLike | undefined = globalThis.localStorage): ThemeState {
+  if (!storage) return { ...DEFAULT_THEME_STATE };
+  return parseThemeState(storage.getItem(THEME_STORAGE_KEY));
+}
+
+export function saveThemeState(state: ThemeState, storage: StorageLike | undefined = globalThis.localStorage): void {
+  try {
+    storage?.setItem(THEME_STORAGE_KEY, JSON.stringify(state));
+  } catch {
+    /* 隐私模式/配额失败静默：仅丢持久化，不丢本次会话生效 */
+  }
+}
+
+/** 把状态落到根元素档位类名（幂等：先清后挂），返回传入的 state 便于链式 */
+export function applyThemeState(state: ThemeState, root: HTMLElement = document.documentElement): ThemeState {
+  root.dataset.theme = state.theme;
+  root.classList.toggle("side-deep", state.sideDeep);
+  root.classList.toggle("side-light", !state.sideDeep);
+  root.classList.toggle("grad-on", state.gradOn);
+  root.classList.toggle("grad-off", !state.gradOn);
+  root.classList.toggle("side-plain", !state.sideFollow);
+  return state;
+}
+
+/** 启动引导：各端 main.ts（或本仓 init 脚本的启动段）于挂载前调用，消除首帧闪色 */
+export function initTheme(): ThemeState {
+  return applyThemeState(loadThemeState());
+}
diff --git a/src/views/Settings.vue b/src/views/Settings.vue
index 8a490ed..8668d74 100644
--- a/src/views/Settings.vue
+++ b/src/views/Settings.vue
@@ -172,6 +172,69 @@
                 </div>
             </div>
 
+            <!-- 我的主题（所有人；主题设置 2026-09-30） -->
+            <div v-else-if="curPane === 'mytheme'" class="pane">
+                <div class="pane-head">
+                    <h3>我的主题</h3>
+                    <p>选择你的管理端主题档，各管理端（通知/用户中心等）同浏览器自动同步；当前来源：<b>{{ myOriginLabel }}</b>（{{ myEffective.theme }}）</p>
+                </div>
+                <div class="theme-pane">
+                    <div class="theme-left">
+                        <div class="theme-grid">
+                            <div
+                                v-for="t in THEME_OPTIONS"
+                                :key="t.key"
+                                :class="['theme-item', { sel: myEffective.theme === t.key, cand: myCandidate === t.key }]"
+                                @click="pickMyTheme(t.key)"
+                            >
+                                <span class="swatch" :style="{ background: t.color }"></span>
+                                <span class="tn">{{ t.name }}</span>
+                                <i v-if="myEffective.theme === t.key" class="tick">✓</i>
+                            </div>
+                        </div>
+                        <div class="pane-foot theme-foot">
+                            <!-- 删用户键后回落学校默认/系统默认（§3.3） -->
+                            <button class="btn plain" @click="followSchoolTheme" :disabled="myOrigin !== 'mine'">跟随学校默认</button>
+                        </div>
+                    </div>
+                    <div class="theme-preview-box">
+                        <iframe :src="previewSrc(myCandidate)" class="theme-iframe" title="主题预览"></iframe>
+                    </div>
+                </div>
+            </div>
+
+            <!-- 本校默认（仅管理员；主题设置 2026-09-30） -->
+            <div v-else-if="curPane === 'schooltheme'" class="pane">
+                <div class="pane-head">
+                    <h3>本校默认</h3>
+                    <p>配置本校师生的推荐主题档（推荐非强制，用户自选优先）；
+                        当前已配置：<b>{{ schConfigured ? (THEME_OPTIONS.find(t => t.key === schConfigured)?.name || schConfigured) : "未配置（系统默认）" }}</b></p>
+                </div>
+                <div class="theme-pane">
+                    <div class="theme-left">
+                        <div class="theme-grid">
+                            <div
+                                v-for="t in THEME_OPTIONS"
+                                :key="t.key"
+                                :class="['theme-item', { sel: schCandidate === t.key }]"
+                                @click="schCandidate = t.key"
+                            >
+                                <span class="swatch" :style="{ background: t.color }"></span>
+                                <span class="tn">{{ t.name }}</span>
+                                <i v-if="schCandidate === t.key" class="tick">✓</i>
+                            </div>
+                        </div>
+                        <div class="pane-foot theme-foot">
+                            <button class="btn primary" :disabled="schSaving" @click="onSaveSchTheme">保存为本校默认</button>
+                            <button class="btn plain" :disabled="schSaving || !schConfigured" @click="onClearSchTheme">跟随系统默认（清空）</button>
+                        </div>
+                    </div>
+                    <div class="theme-preview-box">
+                        <iframe :src="previewSrc(schCandidate)" class="theme-iframe" title="主题预览"></iframe>
+                    </div>
+                </div>
+            </div>
+
             <!-- LOGO 设置（管理员） -->
             <div v-else-if="curPane === 'logo'" class="pane">
                 <div class="pane-head">
@@ -343,8 +406,8 @@ const { $conf } = useCurrentInstance();
 const isAdmin = computed(() => !!store.getIsAdmin);
 
 /** 普通用户不可用的管理 pane（导航隐藏；URL 直达渲染 noperm 黄条，不白屏不报错） */
-const ADMIN_PANES = ["logo", "wallpaper", "sidebar", "sys", "statset", "backend"];
-const ALL_PANES = ["profile", "password", "avatar", "logo", "wallpaper", "sidebar", "sys", "statset", "backend", "noperm"];
+const ADMIN_PANES = ["logo", "wallpaper", "sidebar", "sys", "statset", "backend", "schooltheme"];
+const ALL_PANES = ["profile", "password", "avatar", "mytheme", "schooltheme", "logo", "wallpaper", "sidebar", "sys", "statset", "backend", "noperm"];
 
 const curPane = ref<string>("profile");
 
@@ -374,6 +437,8 @@ interface NavItem {
     key: string;
     name: string;
     icon: string;
+    /** item 级仅管理员可见（主题设置 §3.3：schooltheme 双保险之一，另一道在 ADMIN_PANES） */
+    adminOnly?: boolean;
 }
 const svgWrap = (inner: string) =>
     `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.7" stroke-linecap="round" stroke-linejoin="round">${inner}</svg>`;
@@ -382,6 +447,10 @@ const NAV_ACCOUNT: NavItem[] = [
     { key: "password", name: "修改密码", icon: svgWrap('<rect x="4" y="10" width="16" height="10" rx="2"/><path d="M8 10V7a4 4 0 0 1 8 0v3"/>') },
     { key: "avatar", name: "头像设置", icon: svgWrap('<circle cx="12" cy="12" r="9"/><circle cx="12" cy="10" r="3"/><path d="M6.2 19a6.5 6.5 0 0 1 11.6 0"/>') },
 ];
+const NAV_THEME: NavItem[] = [
+    { key: "mytheme", name: "我的主题", icon: svgWrap('<circle cx="12" cy="12" r="9"/><path d="M12 3a9 9 0 0 0 0 18c1.5 0 2-1 2-2s-1-1.5-1-2.5 1-2 2.5-2H19a2 2 0 0 0 2-2 9 9 0 0 0-9-9z"/><circle cx="7.5" cy="11" r="1"/><circle cx="12" cy="7.5" r="1"/><circle cx="16.5" cy="11" r="1"/>') },
+    { key: "schooltheme", name: "本校默认", icon: svgWrap('<path d="M4 21V8l8-5 8 5v13"/><path d="M4 21h16"/><path d="M12 11v4"/><circle cx="12" cy="9" r="2"/>') },
+];
 const NAV_APPEARANCE: NavItem[] = [
     { key: "logo", name: "LOGO 设置", icon: svgWrap('<rect x="3" y="4" width="18" height="16" rx="2"/><circle cx="8.5" cy="9.5" r="1.5"/><path d="M21 15l-5-5L5 20"/>') },
     { key: "wallpaper", name: "壁纸设置", icon: svgWrap('<path d="M5 3.5A9 9 0 1 0 20.5 12H5z"/><path d="M5 3.5V12h15.5"/>') },
@@ -393,14 +462,19 @@ const NAV_SYSTEM: NavItem[] = [
     { key: "backend", name: "后台管理", icon: svgWrap('<circle cx="12" cy="8" r="3.5"/><path d="M5 20a7 7 0 0 1 14 0"/><circle cx="18" cy="17" r="2.5"/>') },
 ];
 
-/** 分组导航：管理员全可见；普通用户只见「账号」组 */
+/** 分组导航：管理员全可见；普通用户只见「账号」「主题（仅我的主题）」——组级 + item 级（adminOnly）双层过滤 */
 const navGroups = computed(() => {
     const groups = [
         { title: "账号", adminOnly: false, items: NAV_ACCOUNT },
+        { title: "主题", adminOnly: false, items: NAV_THEME },
         { title: "外观", adminOnly: true, items: NAV_APPEARANCE },
         { title: "系统", adminOnly: true, items: NAV_SYSTEM },
     ];
-    return isAdmin.value ? groups : groups.filter(g => !g.adminOnly);
+    const visible = isAdmin.value ? groups : groups.filter(g => !g.adminOnly);
+    return visible.map(g => ({
+        ...g,
+        items: isAdmin.value ? g.items : g.items.filter(it => !it.adminOnly),
+    }));
 });
 
 /* ===== profile：读 store.userInfo（真实展示；保存占位） ===== */
@@ -588,6 +662,153 @@ watch(curPane, pane => {
     }
 });
 
+// ===== 主题（主题设置 2026-09-30：mytheme 所有人 / schooltheme 仅管理员）=====
+import {
+    THEME_STORAGE_KEY,
+    SCHOOL_DEFAULT_STORAGE_KEY,
+    DEFAULT_THEME_STATE,
+    resolveEffectiveThemeState,
+    saveThemeState,
+} from "@/utils/theme";
+import type { ThemeState } from "@/utils/theme";
+
+/** 档位清单本轮硬编码在 UserHome（YschTheme《阶段性方案》§4：痛感已从 ×N 降到 ×1）；主色取自通道 tokens 当前值 */
+const THEME_OPTIONS = [
+    { key: "blue", name: "蔚蓝", color: "#577afb" },
+    { key: "ocean", name: "海洋", color: "#2f7ce0" },
+    { key: "ink", name: "墨青", color: "#3d4d63" },
+    { key: "violet", name: "紫韵", color: "#6d5ae0" },
+    { key: "teal", name: "青碧", color: "#0d9488" },
+];
+
+/** 预览 iframe src：候选档经 URL 覆盖参数拼进 #/theme-preview（§3.2/§3.4，切候选即换 src 重载） */
+function previewSrc(candidate: string) {
+    const cur = resolveEffectiveThemeState();
+    const q = new URLSearchParams();
+    q.set("yh-theme", candidate);
+    q.set("yh-side", cur.sideDeep ? "deep" : "light");
+    q.set("yh-grad", cur.gradOn ? "on" : "off");
+    return `${location.origin}${location.pathname}?${q.toString()}#/theme-preview`;
+}
+
+/** 键在且合法（按 parseThemeState 能还原出用户/学校语义）才计为存在 */
+function keyExists(key: string) {
+    try {
+        return !!localStorage.getItem(key);
+    } catch (e) {
+        return false;
+    }
+}
+
+// ---- 我的主题（所有人）----
+const myCandidate = ref<string>(resolveEffectiveThemeState().theme);
+const myOrigin = computed<"mine" | "school" | "system">(() => {
+    if (keyExists(THEME_STORAGE_KEY)) return "mine";
+    if (keyExists(SCHOOL_DEFAULT_STORAGE_KEY)) return "school";
+    return "system";
+});
+const myOriginLabel = computed(
+    () => ({ mine: "我的选择", school: "学校默认", system: "系统默认" })[myOrigin.value]
+);
+/** 刷新来源/选中态（saveThemeState 是直写 localStorage，无响应式，操作后手动刷） */
+const myTick = ref(0);
+const myEffective = computed(() => {
+    void myTick.value;
+    return resolveEffectiveThemeState();
+});
+
+function pickMyTheme(key: string) {
+    const cur = resolveEffectiveThemeState();
+    saveThemeState({ ...cur, theme: key } as ThemeState);
+    myCandidate.value = key;
+    myTick.value += 1;
+}
+/** 跟随学校默认 = 删用户自选键（之后回落学校档/系统默认，§3.3） */
+function followSchoolTheme() {
+    try {
+        localStorage.removeItem(THEME_STORAGE_KEY);
+    } catch (e) {
+        /* 隐私模式静默 */
+    }
+    myTick.value += 1;
+}
+
+// ---- 本校默认（仅管理员）----
+const schCandidate = ref<string>(resolveEffectiveThemeState().theme);
+const schConfigured = ref<string | null>(null); // 已配置的学校档（theme 名）
+const schTick = ref(0);
+const schSaving = ref(false);
+
+async function loadSchTheme() {
+    try {
+        const res = await BaseApi.getSchTheme();
+        if (res && res.themeState) {
+            try {
+                const st = JSON.parse(res.themeState);
+                schConfigured.value = st.theme || null;
+                schCandidate.value = st.theme || schCandidate.value;
+            } catch (e) {
+                schConfigured.value = null;
+            }
+        } else {
+            schConfigured.value = null;
+        }
+    } catch (e) {
+        /* 读取失败不打扰 */
+    }
+}
+
+/** 保存本校默认：整份 ThemeState JSON（档名=候选，其余继承当前生效值），成功后同步本地键 */
+async function onSaveSchTheme() {
+    if (schSaving.value) return;
+    schSaving.value = true;
+    try {
+        const cur = resolveEffectiveThemeState();
+        const state = { ...cur, theme: schCandidate.value } as ThemeState;
+        await BaseApi.saveSchThemeState(JSON.stringify(state));
+        try {
+            localStorage.setItem(SCHOOL_DEFAULT_STORAGE_KEY, JSON.stringify(state));
+        } catch (e) {
+            /* 隐私模式静默 */
+        }
+        schConfigured.value = schCandidate.value;
+        schTick.value += 1;
+        myTick.value += 1;
+        Message.success("本校默认主题已保存");
+    } catch (error) {
+        Message.error("保存失败:" + error);
+    } finally {
+        schSaving.value = false;
+    }
+}
+
+/** 跟随系统默认（清空学校配置，§3.3：清空=删配置语义） */
+async function onClearSchTheme() {
+    if (schSaving.value) return;
+    schSaving.value = true;
+    try {
+        await BaseApi.clearSchTheme();
+        try {
+            localStorage.removeItem(SCHOOL_DEFAULT_STORAGE_KEY);
+        } catch (e) {
+            /* 隐私模式静默 */
+        }
+        schConfigured.value = null;
+        schTick.value += 1;
+        myTick.value += 1;
+        Message.success("已恢复系统默认");
+    } catch (error) {
+        Message.error("操作失败:" + error);
+    } finally {
+        schSaving.value = false;
+    }
+}
+
+// 打开主题 pane 时拉一次学校配置（管理员视角；失败静默）
+watch(curPane, pane => {
+    if (pane === "mytheme" || pane === "schooltheme") loadSchTheme();
+});
+
 const sidebarItems = ref([
     { name: "通知公告", on: true },
     { name: "流程中心", on: true },
@@ -918,6 +1139,89 @@ function openBackend() {
     }
 }
 
+/* 主题选择（主题设置 2026-09-30）：左色块 + 右预览 iframe（独立 document 吃通道 CSS，本体不吃） */
+.theme-pane {
+    display: flex;
+    gap: 16px;
+    align-items: stretch;
+}
+.theme-left {
+    flex: 0 0 320px;
+}
+.theme-grid {
+    display: grid;
+    grid-template-columns: repeat(2, 1fr);
+    gap: 12px;
+    padding: 4px 0 12px;
+}
+.theme-item {
+    position: relative;
+    height: 84px;
+    border: 2px solid #eef0f3;
+    border-radius: 10px;
+    background: #fff;
+    display: flex;
+    align-items: center;
+    gap: 12px;
+    padding: 0 14px;
+    cursor: pointer;
+    transition: all 0.18s;
+    &:hover {
+        border-color: #5979ea;
+        transform: translateY(-2px);
+        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
+    }
+    &.sel {
+        border-color: #5979ea;
+        box-shadow: 0 0 0 3px rgba(89, 121, 234, 0.18);
+    }
+    .swatch {
+        width: 40px;
+        height: 40px;
+        border-radius: 50%;
+        flex-shrink: 0;
+        box-shadow: inset 0 -6px 12px rgba(0, 0, 0, 0.12);
+    }
+    .tn {
+        font-size: 14px;
+        font-weight: 500;
+        color: #2c3138;
+    }
+    .tick {
+        position: absolute;
+        right: 8px;
+        bottom: 8px;
+        width: 20px;
+        height: 20px;
+        border-radius: 50%;
+        background: #5979ea;
+        color: #fff;
+        font-size: 12px;
+        font-style: normal;
+        display: flex;
+        align-items: center;
+        justify-content: center;
+    }
+}
+.theme-foot {
+    padding-top: 12px;
+}
+.theme-preview-box {
+    flex: 1;
+    min-width: 0;
+    height: 460px;
+    border: 1px solid #eef0f3;
+    border-radius: 10px;
+    overflow: hidden;
+    background: #f5f6f8;
+}
+.theme-iframe {
+    width: 100%;
+    height: 100%;
+    border: none;
+    display: block;
+}
+
 /* 壁纸 / LOGO 网格 */
 .wall-grid {
     display: grid;
diff --git a/src/views/ThemePreview.vue b/src/views/ThemePreview.vue
new file mode 100644
index 0000000..f645b5e
--- /dev/null
+++ b/src/views/ThemePreview.vue
@@ -0,0 +1,142 @@
+<template>
+    <!-- 主题预览页（#/theme-preview，YschTheme《主题设置与通道改动-执行方案》§3.4）：
+         只在本路由的 document 内加载通道（组件挂载时动态 append init 脚本），
+         档位类与通道 CSS 只落在本 document 的 <html> 上——UserHome 本体（父页）永远不吃通道 CSS。
+         纯展示：根容器 pointer-events:none，不渲染搜索区/分页操作/ThemeSwitcher。
+         DOM 结构对齐 Notice layout（header-container / left-menu / path-nav / main-container），
+         观感（配色/侧栏形态）由通道 base.layout.css 按 URL 覆盖参数（?yh-theme= 等）驱动的档位类提供。 -->
+    <div class="theme-preview-root">
+        <header class="header-container fix">
+            <span class="logo-badge fl"><span class="logo-mark">云海</span></span>
+            <div class="delimiter fl align-middle"></div>
+            <h4 class="fl align-middle">管理端预览</h4>
+            <div class="school-bg"></div>
+            <div class="header-aside fr">
+                <span class="name fl align-middle text-ellipsis">演示用户</span>
+                <div class="delimiter fl align-middle"></div>
+                <a href="javascript:;" class="logout fl align-middle" title="退出登陆"><i>⎋</i></a>
+            </div>
+        </header>
+        <div class="left-menu">
+            <div class="menu-top-box"></div>
+            <ul>
+                <li v-for="(m, i) in menus" :key="m" :class="{ active: i === 1 }">
+                    <a href="javascript:void(0);"><span class="menu-dot"></span>{{ m }}</a>
+                </li>
+            </ul>
+            <div class="clear-box"></div>
+        </div>
+        <div class="path-nav">
+            <span>首页</span><span class="crumb-sep">/</span><span>通知管理</span><span class="crumb-sep">/</span><span>通知列表</span>
+        </div>
+        <div class="preview-main">
+            <div class="main-container">
+                <h3 class="panel-title">通知列表</h3>
+                <Table :columns="columns" :data="rows" size="small" :border="true" />
+            </div>
+        </div>
+    </div>
+</template>
+
+<script lang="ts" setup>
+import { onMounted } from "vue";
+import useCurrentInstance from "@/utils/hook/useCurrentInstance";
+
+/**
+ * 主题预览路由页：档位来源 = URL 覆盖参数（?yh-theme= / ?yh-side= / ?yh-grad=，由设置页 iframe src 拼入，
+ * 切候选档即换 src 重载），init 启动段按合成优先级挂档——本组件不读写 localStorage、不提供任何交互。
+ * 直开（不经设置页、未登录）也可渲染：本页由 App.vue 顶层条件分支挂载，不依赖桌面框架与登录态。
+ */
+const { $conf } = useCurrentInstance();
+
+const menus = ["工作台", "通知管理", "统计分析", "应用中心", "系统设置"];
+
+const columns = [
+    { type: "index", title: "序号", width: 70, align: "center" },
+    { title: "标题", key: "title" },
+    { title: "发布人", key: "author", width: 120, align: "center" },
+    { title: "日期", key: "date", width: 160, align: "center" },
+];
+const rows = [
+    { title: "关于国庆节放假安排的通知", author: "校务办", date: "2026-09-28" },
+    { title: "期中教学质量检查实施方案", author: "教务处", date: "2026-09-25" },
+    { title: "校园安全专项检查通报", author: "保卫处", date: "2026-09-21" },
+    { title: "教师信息化能力培训报名", author: "信息中心", date: "2026-09-18" },
+];
+
+onMounted(() => {
+    // 动态引通道 init（仅本 document；UserHome 本体 index.html 不加 loader 是定案）。
+    // baseHost 即通道域（与 UserBase/Notice 的 loader 同源策略）；判重防重复挂载。
+    if (document.querySelector("script[data-yh-theme-init]")) return;
+    const s = document.createElement("script");
+    s.src = `${String($conf.baseHost || "").replace(/\/+$/, "")}/static/js/yh-theme-init.js`;
+    s.setAttribute("data-yh-theme-init", "1");
+    document.head.appendChild(s);
+});
+</script>
+
+<style scoped lang="scss">
+/* 本页只补最小布局；配色/圆角/阴影等观感全部由通道 base.layout.css 的档位类驱动 */
+.theme-preview-root {
+    position: fixed;
+    inset: 0;
+    overflow: hidden;
+    pointer-events: none; /* 纯展示：整页不可交互 */
+    background: #f5f6f8;
+    font-size: 14px;
+}
+
+.header-container {
+    .logo-mark {
+        display: inline-flex;
+        align-items: center;
+        justify-content: center;
+        width: 30px;
+        height: 30px;
+        border-radius: 8px;
+        background: rgba(255, 255, 255, 0.22);
+        color: #fff;
+        font-size: 12px;
+        font-weight: 600;
+    }
+    h4 {
+        color: #fff;
+        font-size: 16px;
+        font-weight: 600;
+        margin: 0 12px;
+    }
+}
+
+.menu-dot {
+    display: inline-block;
+    width: 7px;
+    height: 7px;
+    border-radius: 50%;
+    background: currentColor;
+    opacity: 0.45;
+    margin-right: 9px;
+    vertical-align: middle;
+}
+
+.path-nav .crumb-sep {
+    margin: 0 8px;
+    color: #c5c8cd;
+}
+
+.preview-main {
+    position: fixed;
+    top: calc(var(--topbar-h, 52px) + var(--crumb-h, 44px));
+    left: var(--side-w, 200px);
+    right: 0;
+    bottom: 0;
+    padding: 14px 24px 24px;
+    overflow: auto;
+
+    .panel-title {
+        font-size: 15px;
+        font-weight: 600;
+        color: #2c3138;
+        margin: 4px 0 12px;
+    }
+}
+</style>