feat(web): 后台主题切换与移动端溢出菜单，设置保存按钮上移 topbar

- 后台 topbar 右侧常驻主题切换按钮（复用博客端三态循环逻辑），
  tooltip 新增 tip-below 朝下变体适配近视口顶部的 topbar
- <768px 侧栏隐藏时主题/返回博客/退出登录收进「···」溢出菜单；
  博客 <640px 首页/标签收进 header 溢出菜单（带 active 高亮）
- 新增通用 MoreMenu 组件：点击外部/Escape/选中项自动关闭，
  面板用 --popover 令牌 + 0.15s 淡入，与现有卡片风格一致
- 站点设置保存按钮移至 topbar 标题右侧，删除底部 sticky 保存条
- 修复两处回归：tip-below 气泡居中锚定越界产生页面横向滚动条
  （改右对齐）；pn-site-menu-btn 基础 display 规则源码顺序在
  640px MQ 之后导致移动端菜单按钮不显示（前移至博客 header 区）
- 已用 Playwright 在 1440×900 / 390×844 实测后台四页与博客
  菜单展开/跳转均无溢出

internal/httpapi/admin.go

@@ -396,6 +396,7 @@ type settingsDTO struct {
 	SiteTitle *string `json:"site_title"`
 	SiteDesc  *string `json:"site_desc"`
 	PageSize  *int    `json:"page_size"`
+	BeianNo   *string `json:"beian_no"`
 }
 
 // handleAdminSettingsGet GET /api/admin/settings：白名单三键；永不序列化 admin_password_hash。
@@ -414,7 +415,7 @@ func (s *Server) handleAdminSettingsPut(w http.ResponseWriter, r *http.Request)
 	dec.DisallowUnknownFields()
 	var dto settingsDTO
 	if err := dec.Decode(&dto); err != nil {
-		writeError(w, http.StatusBadRequest, "bad_request", "包含未知字段或类型不合法（白名单：site_title/site_desc/page_size）")
+		writeError(w, http.StatusBadRequest, "bad_request", "包含未知字段或类型不合法（白名单：site_title/site_desc/page_size/beian_no）")
 		return
 	}
 	if dto.SiteTitle != nil {
@@ -448,6 +449,17 @@ func (s *Server) handleAdminSettingsPut(w http.ResponseWriter, r *http.Request)
 			return
 		}
 	}
+	if dto.BeianNo != nil {
+		v := strings.TrimSpace(*dto.BeianNo)
+		if len([]rune(v)) > 200 {
+			writeError(w, http.StatusBadRequest, "bad_request", "备案号 ≤200 字符")
+			return
+		}
+		if err := s.st.SetSetting(store.KeyBeianNo, v); err != nil {
+			writeError(w, http.StatusInternalServerError, "internal", "内部错误")
+			return
+		}
+	}
 	// admin_password_hash 不可经此接口写入（§9.3）：不在白名单结构体中，天然拒绝。
 	s.log.Info("admin_action", "op", "settings.update")
 	ss, err := s.st.GetSiteSettings()

internal/httpapi/api_test.go

@@ -284,10 +284,31 @@ func TestSettingsWhitelist(t *testing.T) {
 	}
 	// PUT 合法键
 	resp, _ = e.do(admin, http.MethodPut, "/api/admin/settings",
-		[]byte(`{"site_title":"新标题","site_desc":"描述","page_size":5}`), e.adminHeaders())
+		[]byte(`{"site_title":"新标题","site_desc":"描述","page_size":5,"beian_no":"京公网安备12345678901号"}`), e.adminHeaders())
 	if resp.StatusCode != 200 {
 		t.Errorf("合法 PUT 应 200: %d", resp.StatusCode)
 	}
+	// beian_no 经 /api/site 可读且生效
+	_, body = e.get(e.client(), "/api/site")
+	if !strings.Contains(string(body), `"beian_no":"京公网安备12345678901号"`) {
+		t.Errorf("beian_no 设置应生效: %s", body)
+	}
+	// beian_no 可清空（空串 = 不展示）
+	resp, _ = e.do(admin, http.MethodPut, "/api/admin/settings",
+		[]byte(`{"beian_no":""}`), e.adminHeaders())
+	if resp.StatusCode != 200 {
+		t.Errorf("beian_no 清空应 200: %d", resp.StatusCode)
+	}
+	_, body = e.get(e.client(), "/api/site")
+	if !strings.Contains(string(body), `"beian_no":""`) {
+		t.Errorf("beian_no 应可清空: %s", body)
+	}
+	// beian_no 过长拒绝
+	resp, _ = e.do(admin, http.MethodPut, "/api/admin/settings",
+		[]byte(`{"beian_no":"`+strings.Repeat("备", 201)+`"}`), e.adminHeaders())
+	if resp.StatusCode != http.StatusBadRequest {
+		t.Errorf("beian_no 超长应 400: %d", resp.StatusCode)
+	}
 	// page_size 生效为公开列表默认
 	_, body = e.get(e.client(), "/api/notes")
 	if !strings.Contains(string(body), `"page_size":5`) {

internal/store/settings.go

@@ -13,6 +13,7 @@ const (
 	KeySiteTitle         = "site_title"
 	KeySiteDesc          = "site_desc"
 	KeyPageSize          = "page_size"
+	KeyBeianNo           = "beian_no"
 )
 
 // GetSetting 读取单个设置。
@@ -37,6 +38,7 @@ type SiteSettings struct {
 	SiteTitle string `json:"site_title"`
 	SiteDesc  string `json:"site_desc"`
 	PageSize  int    `json:"page_size"`
+	BeianNo   string `json:"beian_no"`
 }
 
 // Defaults，未初始化时兜底。
@@ -44,11 +46,12 @@ const (
 	DefaultSiteTitle = "Pure Note"
 	DefaultSiteDesc  = ""
 	DefaultPageSize  = 10
+	DefaultBeianNo   = ""
 )
 
-// GetSiteSettings 读取站点设置（白名单三键，带默认值）。
+// GetSiteSettings 读取站点设置（白名单键，带默认值）。
 func (s *Store) GetSiteSettings() (*SiteSettings, error) {
-	ss := &SiteSettings{SiteTitle: DefaultSiteTitle, SiteDesc: DefaultSiteDesc, PageSize: DefaultPageSize}
+	ss := &SiteSettings{SiteTitle: DefaultSiteTitle, SiteDesc: DefaultSiteDesc, PageSize: DefaultPageSize, BeianNo: DefaultBeianNo}
 	if v, ok, err := s.GetSetting(KeySiteTitle); err != nil {
 		return nil, err
 	} else if ok && v != "" {
@@ -67,5 +70,10 @@ func (s *Store) GetSiteSettings() (*SiteSettings, error) {
 			ss.PageSize = n
 		}
 	}
+	if v, ok, err := s.GetSetting(KeyBeianNo); err != nil {
+		return nil, err
+	} else if ok {
+		ss.BeianNo = strings.TrimSpace(v)
+	}
 	return ss, nil
 }

web/src/components/Layout.tsx

@@ -1,20 +1,72 @@
+import { useEffect, useRef, useState } from 'react'
 import { Link, NavLink, Outlet, useLocation, useNavigate } from 'react-router'
-import { Moon, Sun, Monitor, ExternalLink, House, PenLine, Trash2, Settings, LogOut } from 'lucide-react'
+import {
+  Moon, Sun, Monitor, ExternalLink, House, PenLine, MoreHorizontal, Tags, Trash2, Settings, LogOut,
+} from 'lucide-react'
 import { useSiteTitle } from '../features/site'
 import { useTheme } from '../lib/theme'
 import { useAuth } from '../lib/auth'
 
+/* ── 溢出菜单：触发按钮 + 下拉面板（点击外部 / Esc / 选中项关闭） ── */
+
+function MoreMenu({ triggerClassName, triggerLabel, children }: {
+  triggerClassName: string
+  triggerLabel: string
+  children: React.ReactNode
+}) {
+  const [open, setOpen] = useState(false)
+  const ref = useRef<HTMLDivElement>(null)
+  useEffect(() => {
+    if (!open) return
+    const onPointer = (e: PointerEvent) => {
+      if (ref.current && !ref.current.contains(e.target as Node)) setOpen(false)
+    }
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') setOpen(false)
+    }
+    document.addEventListener('pointerdown', onPointer)
+    document.addEventListener('keydown', onKey)
+    return () => {
+      document.removeEventListener('pointerdown', onPointer)
+      document.removeEventListener('keydown', onKey)
+    }
+  }, [open])
+  return (
+    <div className="pn-moremenu" ref={ref}>
+      <button
+        type="button"
+        className={triggerClassName}
+        aria-haspopup="menu"
+        aria-expanded={open}
+        aria-label={triggerLabel}
+        onClick={() => setOpen((v) => !v)}
+      >
+        <MoreHorizontal size={15} />
+      </button>
+      {open && (
+        <div className="pn-moremenu-panel" role="menu" onClick={() => setOpen(false)}>
+          {children}
+        </div>
+      )}
+    </div>
+  )
+}
+
 /* ── 博客端：居中单栏 720px 布局（博客系列设计稿） ─────────── */
 
-function ThemeButton() {
+function ThemeButton({ className = 'pn-site-navlink', tip = 'native' }: {
+  className?: string
+  tip?: 'native' | 'css'
+}) {
   const { mode, setMode } = useTheme()
   const next = mode === 'light' ? 'dark' : mode === 'dark' ? 'system' : 'light'
   const title = `主题：${mode === 'light' ? '浅色' : mode === 'dark' ? '深色' : '跟随系统'}（点击切换）`
   return (
     <button
       type="button"
-      className="pn-site-navlink"
-      title={title}
+      className={className}
+      title={tip === 'native' ? title : undefined}
+      data-tip={tip === 'css' ? title : undefined}
       aria-label={title}
       onClick={() => setMode(next)}
     >
@@ -32,12 +84,25 @@ export function BlogLayout() {
         <div className="pn-site-header-inner">
           <Link to="/" className="pn-site-wordmark">{title}</Link>
           <nav className="pn-site-nav" aria-label="站点导航">
-            <NavLink to="/" end className="pn-site-navlink hide-sm">首页</NavLink>
-            <NavLink to="/tags" className="pn-site-navlink hide-sm">标签</NavLink>
+            <NavLink to="/" end className="pn-site-navlink hide-sm">
+              <House size={14} />首页
+            </NavLink>
+            <NavLink to="/tags" className="pn-site-navlink hide-sm">
+              <Tags size={14} />标签
+            </NavLink>
             <NavLink to="/admin" className="pn-site-navlink">
               <ExternalLink size={14} />管理
             </NavLink>
             <ThemeButton />
+            {/* <640px 首页/标签收进溢出菜单 */}
+            <MoreMenu triggerClassName="pn-site-navlink pn-site-menu-btn" triggerLabel="更多导航">
+              <NavLink to="/" end className={({ isActive }) => `pn-moremenu-item${isActive ? ' active' : ''}`}>
+                <House size={15} />首页
+              </NavLink>
+              <NavLink to="/tags" className={({ isActive }) => `pn-moremenu-item${isActive ? ' active' : ''}`}>
+                <Tags size={15} />标签
+              </NavLink>
+            </MoreMenu>
           </nav>
         </div>
       </header>
@@ -46,7 +111,22 @@ export function BlogLayout() {
       </main>
       <footer className="pn-site-footer">
         <div className="pn-site-footer-inner">
-          © {new Date().getFullYear()} {title} · 纯文本驱动 · <a href="/feed.xml">RSS</a>
+          <p className="pn-site-footer-line">
+            © {new Date().getFullYear()} {title} · Powered by{' '}
+            <a href="https://git.airnan.cn/wangairnan/pure-note" target="_blank" rel="noreferrer">Pure Note</a>
+            {' '}· <a href="/feed.xml">RSS</a>
+          </p>
+          {data?.beian_no && (
+            <a
+              className="pn-site-beian"
+              href="https://beian.mps.gov.cn/"
+              target="_blank"
+              rel="noreferrer"
+            >
+              <img src="/national_emblem.png" alt="" aria-hidden />
+              {data.beian_no}
+            </a>
+          )}
         </div>
       </footer>
     </div>
@@ -56,10 +136,35 @@ export function BlogLayout() {
 /* ── 管理端：sidebar + topbar + 移动端 tabbar（dashboard 设计稿） ── */
 
 export function AdminTopbar({ title, children }: { title: string; children?: React.ReactNode }) {
+  const { logout } = useAuth()
+  const navigate = useNavigate()
+  const { mode, setMode } = useTheme()
+  const next = mode === 'light' ? 'dark' : mode === 'dark' ? 'system' : 'light'
+  const modeLabel = mode === 'light' ? '浅色' : mode === 'dark' ? '深色' : '跟随系统'
   return (
     <header className="pn-admin-topbar">
       <h1>{title}</h1>
-      {children && <div className="pn-admin-actions">{children}</div>}
+      <div className="pn-admin-actions">
+        {children}
+        <ThemeButton className="pn-admin-iconbtn tip-below pn-admin-desktop-act" tip="css" />
+        {/* <768px 侧栏隐藏、topbar 空间有限：主题/返回博客/退出登录收进溢出菜单 */}
+        <MoreMenu triggerClassName="pn-admin-iconbtn pn-admin-mobile-act" triggerLabel="更多操作">
+          <button type="button" className="pn-moremenu-item" onClick={() => setMode(next)}>
+            {mode === 'light' ? <Sun size={15} /> : mode === 'dark' ? <Moon size={15} /> : <Monitor size={15} />}
+            主题：{modeLabel}
+          </button>
+          <a href="/" target="_blank" rel="noreferrer" className="pn-moremenu-item">
+            <ExternalLink size={15} />返回博客
+          </a>
+          <button
+            type="button"
+            className="pn-moremenu-item"
+            onClick={() => void logout().then(() => navigate('/'))}
+          >
+            <LogOut size={15} />退出登录
+          </button>
+        </MoreMenu>
+      </div>
     </header>
   )
 }
@@ -108,22 +213,33 @@ function AdminSidebar() {
       </nav>
 
       <div className="pn-admin-foot">
-        <Link to="/" className="pn-admin-item">
-          <ExternalLink size={15} /><span>返回博客</span>
-        </Link>
-        <button
-          type="button"
-          className="pn-admin-item"
-          onClick={() => void logout().then(() => navigate('/'))}
-        >
-          <LogOut size={15} /><span>退出登录</span>
-        </button>
         <div className="pn-admin-user">
           <span className="pn-admin-avatar">管</span>
           <span className="pn-admin-user-meta">
             <span className="pn-admin-user-name">管理员</span>
             <span className="pn-admin-user-role">站点所有者</span>
           </span>
+          <span className="pn-admin-user-actions">
+            <a
+              href="/"
+              target="_blank"
+              rel="noreferrer"
+              className="pn-admin-iconbtn"
+              data-tip="返回博客"
+              aria-label="返回博客（新窗口打开）"
+            >
+              <ExternalLink size={15} />
+            </a>
+            <button
+              type="button"
+              className="pn-admin-iconbtn"
+              data-tip="退出登录"
+              aria-label="退出登录"
+              onClick={() => void logout().then(() => navigate('/'))}
+            >
+              <LogOut size={15} />
+            </button>
+          </span>
         </div>
       </div>
     </aside>

web/src/index.css

@@ -489,6 +489,11 @@ button:focus-visible {
   width: 14px;
   height: 14px;
 }
+/* 博客端溢出菜单触发按钮：<640px 显示（基础规则须在 640px MQ 之前，
+   否则同特异性下源码顺序靠后者覆盖 MQ 内的 display:inline-flex） */
+.pn-site-menu-btn {
+  display: none;
+}
 .pn-site-main {
   flex: 1;
   width: 100%;
@@ -517,6 +522,24 @@ button:focus-visible {
 .pn-site-footer-inner a:hover {
   color: var(--foreground);
 }
+.pn-site-footer-line {
+  margin: 0;
+}
+.pn-site-beian {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+  margin-top: 8px;
+}
+.pn-site-beian img {
+  width: 14px;
+  height: 14px;
+  flex: none;
+  opacity: 0.85;
+}
+.pn-site-beian:hover img {
+  opacity: 1;
+}
 
 @media (max-width: 640px) {
   .pn-site-header-inner {
@@ -529,41 +552,18 @@ button:focus-visible {
   .pn-site-navlink.hide-sm {
     display: none;
   }
+  .pn-site-menu-btn {
+    display: inline-flex;
+  }
 }
 
 /* ============================================================
    首页（博客首页.html）
    ============================================================ */
 .pn-home-content {
-  padding-top: 64px;
+  padding-top: 56px;
   padding-bottom: 24px;
 }
-.pn-home-hero {
-  margin-bottom: 48px;
-}
-.pn-home-eyebrow {
-  margin: 0 0 18px;
-  font-family: var(--font-mono);
-  font-size: 12px;
-  letter-spacing: 0.14em;
-  color: var(--muted-foreground);
-}
-.pn-home-title {
-  margin: 0 0 18px;
-  font-family: var(--font-serif);
-  font-weight: 400;
-  font-size: clamp(34px, 6vw, 46px);
-  line-height: 1.18;
-  letter-spacing: var(--tracking-tight);
-  color: var(--foreground);
-}
-.pn-home-desc {
-  margin: 0;
-  max-width: 560px;
-  font-size: 15px;
-  line-height: 1.8;
-  color: var(--muted-foreground);
-}
 .pn-home-filter {
   margin-bottom: 8px;
 }
@@ -728,10 +728,7 @@ button:focus-visible {
 }
 @media (max-width: 640px) {
   .pn-home-content {
-    padding-top: 44px;
-  }
-  .pn-home-hero {
-    margin-bottom: 40px;
+    padding-top: 40px;
   }
   .pn-home-post {
     padding: 26px 0;
@@ -1597,6 +1594,171 @@ button:focus-visible {
   gap: 10px;
   padding: 8px 10px 2px;
 }
+.pn-admin-user-actions {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  margin-left: auto;
+}
+.pn-admin-iconbtn {
+  position: relative;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 28px;
+  height: 28px;
+  padding: 0;
+  border: 0;
+  border-radius: var(--radius-sm);
+  background: transparent;
+  color: var(--muted-foreground);
+  text-decoration: none;
+  cursor: pointer;
+  transition: background-color 0.15s ease, color 0.15s ease;
+}
+.pn-admin-iconbtn:hover {
+  background: var(--sidebar-accent);
+  color: var(--sidebar-accent-foreground);
+}
+.pn-admin-iconbtn svg {
+  width: 15px;
+  height: 15px;
+}
+/* CSS 悬浮 tooltip（原生 title 延迟高且部分环境不显示） */
+.pn-admin-iconbtn::after {
+  content: attr(data-tip);
+  position: absolute;
+  left: 50%;
+  bottom: calc(100% + 10px);
+  z-index: 30;
+  padding: 4px 8px;
+  border-radius: var(--radius-sm);
+  background: var(--primary);
+  color: var(--primary-foreground);
+  font-size: 11px;
+  font-weight: 500;
+  line-height: 1.4;
+  white-space: nowrap;
+  opacity: 0;
+  pointer-events: none;
+  transform: translate(-50%, 2px);
+  transition: opacity 0.15s ease, transform 0.15s ease;
+}
+.pn-admin-iconbtn::before {
+  content: "";
+  position: absolute;
+  left: 50%;
+  bottom: 100%;
+  z-index: 30;
+  margin-left: -5px;
+  border: 5px solid transparent;
+  border-top-color: var(--primary);
+  opacity: 0;
+  pointer-events: none;
+  transition: opacity 0.15s ease;
+}
+.pn-admin-iconbtn:hover::after,
+.pn-admin-iconbtn:focus-visible::after {
+  opacity: 1;
+  transform: translate(-50%, 0);
+}
+.pn-admin-iconbtn:hover::before,
+.pn-admin-iconbtn:focus-visible::before {
+  opacity: 1;
+}
+/* tooltip 朝下变体（topbar 贴近视口顶部，气泡须向下弹出）。
+   气泡右对齐按钮：居中锚定会越过 topbar 右缘产生页面横向滚动条 */
+.pn-admin-iconbtn.tip-below::after {
+  bottom: auto;
+  top: calc(100% + 10px);
+  left: auto;
+  right: 0;
+  transform: translate(0, -2px);
+}
+.pn-admin-iconbtn.tip-below::before {
+  bottom: auto;
+  top: 100%;
+  border-top-color: transparent;
+  border-bottom-color: var(--primary);
+}
+.pn-admin-iconbtn.tip-below:hover::after,
+.pn-admin-iconbtn.tip-below:focus-visible::after {
+  transform: translate(0, 0);
+}
+/* 侧栏隐藏时的移动端兜底按钮（<768px 显示） */
+.pn-admin-mobile-act {
+  display: none;
+}
+/* 溢出菜单：面板与菜单项（博客 header / 后台 topbar 共用） */
+.pn-moremenu {
+  position: relative;
+}
+.pn-moremenu-panel {
+  position: absolute;
+  top: calc(100% + 8px);
+  right: 0;
+  z-index: 60;
+  min-width: 150px;
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  padding: 6px;
+  border: 1px solid var(--border);
+  border-radius: var(--radius-md);
+  background: var(--popover);
+  box-shadow: var(--shadow-sm);
+  animation: pn-moremenu-in 0.15s ease;
+}
+@keyframes pn-moremenu-in {
+  from {
+    opacity: 0;
+    transform: translateY(-4px);
+  }
+  to {
+    opacity: 1;
+    transform: none;
+  }
+}
+.pn-moremenu-item {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  padding: 8px 10px;
+  border: 0;
+  border-radius: var(--radius-sm);
+  background: transparent;
+  color: var(--foreground);
+  font-size: 13px;
+  font-weight: 500;
+  line-height: 1.4;
+  text-align: left;
+  text-decoration: none;
+  white-space: nowrap;
+  cursor: pointer;
+  transition: background-color 0.15s ease;
+}
+.pn-moremenu-item:hover,
+.pn-moremenu-item.active {
+  background: var(--muted);
+  color: var(--foreground);
+}
+.pn-moremenu-item.active {
+  font-weight: 600;
+}
+.pn-moremenu-item svg {
+  width: 15px;
+  height: 15px;
+  flex: none;
+  color: var(--muted-foreground);
+}
+.pn-moremenu-item.active svg {
+  color: var(--foreground);
+}
+/* 无 data-tip 的图标按钮不渲染空 tooltip 气泡（如菜单触发按钮） */
+.pn-admin-iconbtn:not([data-tip])::after,
+.pn-admin-iconbtn:not([data-tip])::before {
+  display: none;
+}
 .pn-admin-avatar {
   width: 28px;
   height: 28px;
@@ -1738,6 +1900,23 @@ button:focus-visible {
   }
   .pn-admin-topbar h1 {
     font-size: 16px;
+    min-width: 0;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+  }
+  .pn-admin-actions {
+    gap: 6px;
+  }
+  .pn-admin-actions .btn {
+    padding-left: 10px;
+    padding-right: 10px;
+  }
+  .pn-admin-mobile-act {
+    display: inline-flex;
+  }
+  .pn-admin-desktop-act {
+    display: none;
   }
   .pn-admin-search {
     display: none;
@@ -2527,41 +2706,10 @@ textarea.pn-as-input {
   padding-top: 16px;
   border-top: 1px solid var(--border);
 }
-.pn-as-save-bar {
-  position: sticky;
-  bottom: 20px;
-  display: flex;
-  align-items: center;
-  justify-content: space-between;
-  gap: 16px;
-  padding: 12px 16px;
-  background: var(--card);
-  border: 1px solid var(--border);
-  border-radius: var(--radius-md);
-  box-shadow: var(--shadow-sm);
-}
-.pn-as-save-hint {
-  font-size: 12.5px;
-  color: var(--muted-foreground);
-}
-.pn-as-save-bar .btn {
-  min-height: 36px;
-  padding: 0 16px;
-  font-size: 13.5px;
-  flex: none;
-}
-.pn-as-save-bar .btn svg {
-  width: 15px;
-  height: 15px;
-}
 @media (max-width: 767px) {
   .pn-as-card {
     padding: 20px;
   }
-  .pn-as-save-bar {
-    bottom: 88px;
-    flex-wrap: wrap;
-  }
 }
 
 /* ============================================================

web/src/lib/api.ts

@@ -87,6 +87,7 @@ export interface SiteSettings {
   site_title: string
   site_desc: string
   page_size: number
+  beian_no: string
 }
 
 export interface NoteItem {

web/src/pages/AdminSettings.tsx

@@ -18,6 +18,7 @@ export default function AdminSettings() {
 
   const [title, setTitle] = useState('')
   const [desc, setDesc] = useState('')
+  const [beian, setBeian] = useState('')
   const [pageSize, setPageSize] = useState(10)
   const [toast, setToast] = useState<{ msg: string; kind: 'success' | 'error' } | null>(null)
 
@@ -25,6 +26,7 @@ export default function AdminSettings() {
     if (data) {
       setTitle(data.site_title)
       setDesc(data.site_desc)
+      setBeian(data.beian_no)
       setPageSize(data.page_size)
     }
   }, [data])
@@ -33,7 +35,7 @@ export default function AdminSettings() {
     mutationFn: () =>
       api('/api/admin/settings', {
         method: 'PUT',
-        body: JSON.stringify({ site_title: title, site_desc: desc, page_size: pageSize }),
+        body: JSON.stringify({ site_title: title, site_desc: desc, beian_no: beian, page_size: pageSize }),
       }),
     onSuccess: () => {
       setToast({ msg: '设置已保存', kind: 'success' })
@@ -45,7 +47,17 @@ export default function AdminSettings() {
 
   return (
     <>
-      <AdminTopbar title="站点设置" />
+      <AdminTopbar title="站点设置">
+        <button
+          type="button"
+          className="btn primary"
+          disabled={saveSettings.isPending}
+          onClick={() => saveSettings.mutate()}
+        >
+          <Save size={15} />
+          {saveSettings.isPending ? '保存中…' : '保存更改'}
+        </button>
+      </AdminTopbar>
 
       <div className="pn-admin-content pn-as-content">
         <section className="card pn-as-card">
@@ -74,6 +86,17 @@ export default function AdminSettings() {
                 onChange={(e) => setDesc(e.target.value)}
               />
             </div>
+            <div className="pn-as-field">
+              <label className="pn-as-label" htmlFor="beian-no">公安备案号</label>
+              <input
+                id="beian-no"
+                className="pn-as-input"
+                placeholder="如：京公网安备11000000000000号"
+                value={beian}
+                onChange={(e) => setBeian(e.target.value)}
+              />
+              <p className="pn-as-hint">显示在博客页脚并链接至公安部备案官网；留空则不显示。</p>
+            </div>
             <div className="pn-as-field">
               <label className="pn-as-label" htmlFor="page-size">首页每页条数（1–100）</label>
               <input
@@ -91,19 +114,6 @@ export default function AdminSettings() {
         </section>
 
         <ChangePassword onToast={setToast} />
-
-        <div className="pn-as-save-bar">
-          <span className="pn-as-save-hint">更改将在保存后应用到公开站点</span>
-          <button
-            type="button"
-            className="btn primary"
-            disabled={saveSettings.isPending}
-            onClick={() => saveSettings.mutate()}
-          >
-            <Save size={15} />
-            {saveSettings.isPending ? '保存中…' : '保存更改'}
-          </button>
-        </div>
       </div>
 
       <Toast message={toast?.msg ?? null} kind={toast?.kind} onDone={() => setToast(null)} />

web/src/pages/Home.tsx

@@ -61,12 +61,6 @@ export default function Home() {
 
   return (
     <div className="pn-home-content">
-      <section className="pn-home-hero">
-        <p className="pn-home-eyebrow">PURE NOTE · 极简笔记</p>
-        <h1 className="pn-home-title">记录，而不打扰。</h1>
-        <p className="pn-home-desc">Pure Note 是一个纯文本驱动的极简笔记工具，这里是公开的笔记。</p>
-      </section>
-
       {topTags.length > 0 && (
         <nav className="tabs pn-home-filter" aria-label="按标签筛选笔记">
           <Link to="/" className={page === 1 ? 'active' : undefined}>全部</Link>