diff --git a/docs/CHANGELOG_web.md b/docs/CHANGELOG_web.md
index c132378..7d21458 100644
--- a/docs/CHANGELOG_web.md
+++ b/docs/CHANGELOG_web.md
@@ -34,8 +34,8 @@ The format loosely follows Keep a Changelog and can be adapted to the team's hab
 - The web UI was rebuilt on a shadcn/Radix design system: semantic light/dark theme tokens with a system/light/dark switcher (remembered), a persistent app shell (desktop sidebar, tablet icon rail, mobile bottom tabs), a shelf driven by URL-state search/sort/group controls with a flat-first grid and menu-based card actions (confirm dialogs replace native popups), and rebuilt login/admin pages. Readers keep their current chrome and every reading interaction this round; their restyle lands next.
 - 网页 UI 以 shadcn/Radix 设计系统重做:语义化明暗主题 token + 系统/浅色/深色切换(记忆);常驻应用壳(桌面侧栏、平板图标栏、手机底部标签);书架改为 URL 状态驱动的搜索/排序/分组工具条,默认平铺网格,卡片操作收进菜单(删除改为对话框确认);登录页与 admin 两页同步重做。阅读器保持现状,改版随下一期到达。
 
-- Shelf rebuilt into a content-first library UI: responsive cover grid (auto-fill 3:4 posters) with a pages/size caption, color-coded format badges, in-cover progress bars, staggered entrance animations, skeleton loading, and dedicated empty/error/searching states; 继续阅读 is now a horizontal resume strip (cover + progress + library); login got a brand card with icon-adorned inputs; toasts animate with icons; missing covers render a serif-initial placeholder instead of an endless pulse.
-- 书架重构为「内容优先」的现代书库界面：响应式封面网格（自适应列宽、3:4 海报），封面下方显示页数/大小、格式彩色徽章、封面内嵌进度条、卡片错峰入场动画、骨架屏加载与空/错/搜索无结果专属状态；「继续阅读」改为横向续读卡片条（封面+进度+所属库）；登录页升级为主视觉卡片与带图标输入框；Toast 带动画与图标；无封面书籍以衬线首字占位，不再无限脉冲。
+- Shelf rebuilt into a content-first library UI: responsive cover grid (auto-fill 3:4 posters) with a pages/size caption, color-coded format badges, in-cover progress bars, staggered entrance animations, skeleton loading, and dedicated empty/error/searching states; 继续阅读 is now a horizontal resume strip (cover + progress + library); login got a clean brand card; toasts animate with icons; missing covers render a serif-initial placeholder instead of an endless pulse.
+- 书架重构为「内容优先」的现代书库界面：响应式封面网格（自适应列宽、3:4 海报），封面下方显示页数/大小、格式彩色徽章、封面内嵌进度条、卡片错峰入场动画、骨架屏加载与空/错/搜索无结果专属状态；「继续阅读」改为横向续读卡片条（封面+进度+所属库）；登录页升级为主视觉卡片；Toast 带动画与图标；无封面书籍以衬线首字占位，不再无限脉冲。
 
 - .txt chapter splitting no longer recognizes volumes: 「第X卷/部」 lines stay plain body text and volume-only books fall back to pseudo-sections as before; chapter switching moves from the dropdown to a 目录 sidebar overlay that highlights the current chapter, scrolls it into view, and closes on click-outside or after picking a chapter.
 - .txt 章节切分不再感知卷:「第X卷/部」行只作为正文文本,只有卷的书和以前一样退回伪章节切分;换章从下拉框改为「目录」侧边栏浮层——当前章高亮并自动居中可见,点击空白处或选定章节即收起。
diff --git a/frontend/src/components/app-shell.tsx b/frontend/src/components/app-shell.tsx
index fb683a8..9352366 100644
--- a/frontend/src/components/app-shell.tsx
+++ b/frontend/src/components/app-shell.tsx
@@ -1,6 +1,6 @@
 import { useQuery } from "@tanstack/react-query";
 import { BookMarked, BookOpen, FolderCog, LogOut, Users } from "lucide-react";
-import { NavLink, Outlet, useLocation } from "react-router-dom";
+import { Link, NavLink, Outlet, useLocation } from "react-router-dom";
 import { api } from "@/api/client";
 import { useAuth } from "@/auth/AuthContext";
 import { Button } from "@/components/ui/button";
@@ -10,31 +10,32 @@ import { ThemeToggle } from "./theme-toggle";
 import { cn } from "@/lib/utils";
 import type { ReactNode } from "react";
 
-function Brand({ compact }: { compact?: boolean }) {
+function Brand() {
   return (
-    <NavLink to="/" className="flex h-12 shrink-0 items-center gap-2 rounded-md px-3 focus-visible:outline-2 focus-visible:outline-offset-2">
+    <Link to="/" aria-label="BookLib 首页" className="flex h-12 shrink-0 items-center gap-2 rounded-md px-3 focus-visible:outline-2 focus-visible:outline-offset-2">
       <span className="grid size-6 place-items-center rounded bg-accent text-accent-foreground">
         <BookMarked className="size-4" />
       </span>
-      {!compact && <span className="text-[15px] font-semibold tracking-tight">BookLib</span>}
-    </NavLink>
+      <span className="hidden text-[15px] font-semibold tracking-tight lg:inline">BookLib</span>
+    </Link>
   );
 }
 
-function NavItem({ to, icon, label, search }: { to: string; icon: ReactNode; label: string; search?: string }) {
+/* NavLink 不可用:其 isActive/aria-current 前缀匹配 "/" 会无视 search,导致 ?lib=N 全部同时高亮 */
+function NavItem({ to, icon, label, active }: { to: string; icon: ReactNode; label: string; active: boolean }) {
   return (
-    <NavLink
-      to={to + (search ?? "")}
-      className={({ isActive }) =>
-        cn(
-          "flex items-center gap-3 rounded-md px-3 py-2 text-sm text-muted-foreground transition-colors hover:bg-secondary hover:text-foreground",
-          isActive && "bg-secondary font-medium text-foreground",
-        )
-      }
+    <Link
+      to={to}
+      aria-label={label}
+      aria-current={active ? "page" : undefined}
+      className={cn(
+        "flex items-center gap-3 rounded-md px-3 py-2 text-sm text-muted-foreground transition-colors hover:bg-secondary hover:text-foreground",
+        active && "bg-secondary font-medium text-foreground",
+      )}
     >
       {icon}
       <span className="hidden lg:inline">{label}</span>
-    </NavLink>
+    </Link>
   );
 }
 
@@ -43,12 +44,13 @@ export function AppShell() {
   const loc = useLocation();
   const libsQ = useQuery({ queryKey: ["libraries"], queryFn: api.listLibraries });
   const libs = libsQ.data ?? [];
+  const libParam = new URLSearchParams(loc.search).get("lib");
 
   const account = (
     <DropdownMenu>
       <DropdownMenuTrigger asChild>
-        <Button variant="ghost" className="gap-2 px-2">
-          <span className="grid size-7 place-items-center rounded-full bg-accent/15 text-xs font-semibold text-accent">
+        <Button variant="ghost" className="gap-2 px-2" aria-label={`账户 ${user?.username ?? ""}`}>
+          <span className="grid size-7 place-items-center rounded-full bg-accent/15 text-xs font-semibold text-accent-strong">
             {Array.from(user?.username ?? "?")[0]?.toUpperCase()}
           </span>
           <span className="hidden max-w-28 truncate text-sm lg:inline">{user?.username}</span>
@@ -67,14 +69,14 @@ export function AppShell() {
   return (
     <div className="flex h-full">
       {/* 桌面/平板侧栏;lg 全文标签,md 图标栏 */}
-      <aside className="hidden w-14 shrink-0 flex-col gap-1 border-r bg-card/60 p-2 md:flex lg:w-60">
-        <Brand compact />
+      <aside className="hidden w-14 shrink-0 flex-col gap-1 border-r bg-background/85 p-2 backdrop-blur md:flex lg:w-60">
+        <Brand />
         <nav aria-label="主导航" className="flex flex-col gap-1">
-          <NavItem to="/" icon={<BookOpen className="size-4 shrink-0" />} label="书架" />
+          <NavItem to="/" icon={<BookOpen className="size-4 shrink-0" />} label="书架" active={loc.pathname === "/" && !libParam} />
           {isAdmin && (
             <>
-              <NavItem to="/admin/libraries" icon={<FolderCog className="size-4 shrink-0" />} label="库管理" />
-              <NavItem to="/admin/users" icon={<Users className="size-4 shrink-0" />} label="用户管理" />
+              <NavItem to="/admin/libraries" icon={<FolderCog className="size-4 shrink-0" />} label="库管理" active={loc.pathname.startsWith("/admin/libraries")} />
+              <NavItem to="/admin/users" icon={<Users className="size-4 shrink-0" />} label="用户管理" active={loc.pathname.startsWith("/admin/users")} />
             </>
           )}
         </nav>
@@ -82,9 +84,8 @@ export function AppShell() {
           <div className="mt-3 hidden min-h-0 flex-1 flex-col lg:flex">
             <p className="px-3 pb-1 text-[11px] font-medium uppercase tracking-wider text-muted-foreground">书库</p>
             <div className="min-h-0 flex-1 overflow-y-auto">
-              <NavItem to="/" search="?lib=0" icon={<span className="size-1.5 shrink-0 rounded-full bg-muted-foreground/50" />} label="全部" />
               {libs.map((l) => (
-                <NavItem key={l.id} to="/" search={`?lib=${l.id}`} icon={<span className="size-1.5 shrink-0 rounded-full bg-accent/60" />} label={l.name} />
+                <NavItem key={l.id} to={`/?lib=${l.id}`} icon={<span className="size-1.5 shrink-0 rounded-full bg-accent/60" />} label={l.name} active={loc.pathname === "/" && libParam === String(l.id)} />
               ))}
             </div>
           </div>
@@ -98,7 +99,7 @@ export function AppShell() {
 
       <div className="flex min-w-0 flex-1 flex-col">
         {/* 移动端顶栏 */}
-        <header className="flex h-12 shrink-0 items-center justify-between border-b bg-card/60 px-3 lg:hidden">
+        <header className="flex h-12 shrink-0 items-center justify-between border-b bg-background/85 px-3 backdrop-blur lg:hidden">
           <Brand />
           <div className="flex items-center gap-1">
             <ThemeToggle />
@@ -109,8 +110,8 @@ export function AppShell() {
           <Outlet />
         </main>
         {/* 移动端底 Tab */}
-        <nav aria-label="底部导航" className="flex h-14 shrink-0 items-stretch border-t bg-card/90 backdrop-blur md:hidden">
-          <TabItem to="/" icon={<BookOpen className="size-5" />} label="书架" search="?lib=0" />
+        <nav aria-label="底部导航" className="flex h-14 shrink-0 items-stretch border-t bg-background/85 backdrop-blur md:hidden">
+          <TabItem to="/" icon={<BookOpen className="size-5" />} label="书架" />
           {isAdmin && <TabItem to="/admin/libraries" icon={<FolderCog className="size-5" />} label="库管理" />}
           {isAdmin && <TabItem to="/admin/users" icon={<Users className="size-5" />} label="用户" />}
         </nav>
@@ -119,9 +120,9 @@ export function AppShell() {
   );
 }
 
-function TabItem({ to, icon, label, search }: { to: string; icon: ReactNode; label: string; search?: string }) {
+function TabItem({ to, icon, label }: { to: string; icon: ReactNode; label: string }) {
   return (
-    <NavLink to={to + (search ?? "")} className={({ isActive }) => cn("flex flex-col items-center justify-center gap-0.5 text-[11px] text-muted-foreground", isActive && "text-accent")}>
+    <NavLink to={to} end={to === "/"} className={({ isActive }) => cn("flex flex-col items-center justify-center gap-0.5 text-[11px] text-muted-foreground", isActive && "text-accent-strong")}>
       {icon}
       {label}
     </NavLink>
diff --git a/frontend/src/components/ui.ts b/frontend/src/components/ui.ts
index 4de5654..ada501d 100644
--- a/frontend/src/components/ui.ts
+++ b/frontend/src/components/ui.ts
@@ -1,7 +1,5 @@
 import type { Format } from "../api/types";
 
-export { formatSize } from "../lib/format"; // deprecated: phase-2 随阅读器清除
-
 export const btn =
   "inline-flex items-center gap-1.5 rounded-lg bg-white/[0.06] px-3 py-1.5 text-sm ring-1 ring-white/10 transition-colors hover:bg-white/[0.11] focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-amber-500 active:bg-white/[0.15] disabled:cursor-not-allowed disabled:opacity-50";
 export const btnGhost =
diff --git a/frontend/src/index.css b/frontend/src/index.css
index 6d2e7c7..c0878b2 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -18,8 +18,10 @@
   --muted: oklch(0.95 0.003 80);
   --muted-foreground: oklch(0.55 0.008 70);
   --accent: oklch(0.68 0.16 46);
+  --accent-strong: oklch(0.55 0.17 46);
   --accent-foreground: oklch(0.985 0.002 80);
   --destructive: oklch(0.58 0.21 27);
+  --destructive-foreground: oklch(0.98 0.002 80);
   --border: oklch(0.91 0.004 80);
   --input: oklch(0.91 0.004 80);
   --ring: oklch(0.62 0.01 70);
@@ -38,8 +40,10 @@
   --muted: oklch(0.28 0.006 80);
   --muted-foreground: oklch(0.68 0.006 80);
   --accent: oklch(0.7 0.16 46);
+  --accent-strong: oklch(0.72 0.16 46);
   --accent-foreground: oklch(0.19 0.006 80);
   --destructive: oklch(0.65 0.19 25);
+  --destructive-foreground: oklch(0.19 0.006 80);
   --border: oklch(1 0 0 / 10%);
   --input: oklch(1 0 0 / 14%);
   --ring: oklch(0.6 0.01 70);
@@ -63,8 +67,10 @@
   --color-muted: var(--muted);
   --color-muted-foreground: var(--muted-foreground);
   --color-accent: var(--accent);
+  --color-accent-strong: var(--accent-strong);
   --color-accent-foreground: var(--accent-foreground);
   --color-destructive: var(--destructive);
+  --color-destructive-foreground: var(--destructive-foreground);
   --color-border: var(--border);
   --color-input: var(--input);
   --color-ring: var(--ring);
diff --git a/frontend/src/pages/Shelf.tsx b/frontend/src/pages/Shelf.tsx
index 643587b..5d8d027 100644
--- a/frontend/src/pages/Shelf.tsx
+++ b/frontend/src/pages/Shelf.tsx
@@ -27,12 +27,12 @@ function BookCard({ book, index, onOpen, onDelete }: { book: Book; index: number
   const pct = Math.round(book.percent * 100);
   return (
     <div className="group fx-rise relative flex flex-col" style={{ animationDelay: `${Math.min(index, 23) * 25}ms` }}>
-      <button onClick={onOpen} className="block w-full p-0 text-left focus-visible:outline-none">
+      <button onClick={onOpen} className="block w-full rounded-md p-0 text-left outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2">
         <span className="relative block aspect-[3/4] overflow-hidden rounded-md border bg-muted shadow-sm transition group-hover:shadow-md group-hover:ring-2 group-hover:ring-accent/50">
           <Cover book={book} className="size-full" />
           <span className={formatBadge(book.format, "absolute left-1.5 top-1.5")}>{book.format}</span>
           {book.state === "error" && (
-            <span className="absolute right-1.5 top-1.5 flex items-center gap-1 rounded bg-destructive px-1.5 py-0.5 text-[10px] font-semibold text-primary-foreground" title={book.error}>
+            <span className="absolute right-1.5 top-1.5 flex items-center gap-1 rounded bg-destructive px-1.5 py-0.5 text-[10px] font-semibold text-destructive-foreground" title={book.error}>
               <TriangleAlert className="size-3" /> 损坏
             </span>
           )}
@@ -47,7 +47,7 @@ function BookCard({ book, index, onOpen, onDelete }: { book: Book; index: number
           {book.path.includes("/") ? book.path.slice(0, book.path.lastIndexOf("/")) : `${book.pages > 0 ? book.pages + " 页 · " : ""}${formatSize(book.size)}`}
         </span>
       </button>
-      <div className="absolute right-1 top-1 z-10 opacity-0 transition-opacity focus-within:opacity-100 group-hover:opacity-100">
+      <div className="absolute right-1 top-1 z-10 opacity-100 transition-opacity md:opacity-0 md:focus-within:opacity-100 md:group-hover:opacity-100">
         <DropdownMenu>
           <DropdownMenuTrigger asChild>
             <Button variant="secondary" size="icon" className="size-7 bg-background/80 backdrop-blur" aria-label={`《${book.title}》操作`}>
@@ -55,11 +55,11 @@ function BookCard({ book, index, onOpen, onDelete }: { book: Book; index: number
             </Button>
           </DropdownMenuTrigger>
           <DropdownMenuContent align="end">
-            <DropdownMenuItem onClick={onOpen}>打开</DropdownMenuItem>
+            <DropdownMenuItem onSelect={onOpen}>打开</DropdownMenuItem>
             {isAdmin && (
               <>
                 <DropdownMenuSeparator />
-                <DropdownMenuItem className="text-destructive focus:text-destructive" onClick={onDelete}>
+                <DropdownMenuItem variant="destructive" onSelect={onDelete}>
                   删除
                 </DropdownMenuItem>
               </>
@@ -74,7 +74,7 @@ function BookCard({ book, index, onOpen, onDelete }: { book: Book; index: number
 function SectionHead({ label, count }: { label: string; count: number }) {
   if (!label) return null;
   return (
-    <h2 className="sticky top-0 z-10 mb-3 flex items-center gap-2 bg-background/90 py-1.5 text-sm font-medium backdrop-blur">
+    <h2 className="sticky top-0 z-10 mb-3 flex items-center gap-2 bg-background/85 py-1.5 text-sm font-medium backdrop-blur">
       <FolderOpen className="size-4 text-muted-foreground" />
       {label}
       <span className="text-xs tabular-nums text-muted-foreground">{count}</span>
@@ -148,7 +148,7 @@ export default function Shelf() {
 
   return (
     <div className="mx-auto flex w-full max-w-6xl flex-col px-4 pb-20 sm:px-6 md:pb-6">
-      <div className="sticky top-0 z-20 -mx-4 mb-6 flex flex-wrap items-center gap-2 border-b bg-background/90 px-4 py-3 backdrop-blur sm:-mx-6 sm:px-6">
+      <div className="sticky top-0 z-20 -mx-4 mb-6 flex flex-wrap items-center gap-2 border-b bg-background/85 px-4 py-3 backdrop-blur sm:-mx-6 sm:px-6">
         <div className="relative min-w-0 flex-1 sm:max-w-64">
           <Search className="pointer-events-none absolute left-2.5 top-1/2 size-4 -translate-y-1/2 text-muted-foreground" />
           <Input className="pl-8" type="search" aria-label="搜索标题" placeholder="搜索标题…" value={qRaw} onChange={(e) => setQRaw(e.target.value)} />
@@ -163,7 +163,7 @@ export default function Shelf() {
           <DropdownMenuContent align="end">
             <DropdownMenuLabel>排序</DropdownMenuLabel>
             {SORTS.map((k) => (
-              <DropdownMenuItem key={k} onClick={() => setParam("sort", k === "added" ? "" : k)} className={k === sort ? "font-medium text-accent" : ""}>
+              <DropdownMenuItem key={k} onSelect={() => setParam("sort", k === "added" ? "" : k)} className={k === sort ? "font-medium text-accent-strong" : ""}>
                 {SORT_LABEL[k]}
               </DropdownMenuItem>
             ))}
@@ -190,7 +190,7 @@ export default function Shelf() {
       {lib === LIB0 && <p className="sr-only" aria-live="polite">{`当前筛选:${libName}`}</p>}
 
       {(libsQ.data ?? []).length === 0 && !libsQ.isPending && !searching && (
-        <p className="mb-6 flex items-center gap-2 rounded-md border border-accent/30 bg-accent/10 px-3 py-2 text-sm text-accent">
+        <p className="mb-6 flex items-center gap-2 rounded-md border border-accent/30 bg-accent/10 px-3 py-2 text-sm text-accent-strong">
           <LibraryBig className="size-4 shrink-0" />
           还没有书库。admin 请到「库管理」建库并扫描。
         </p>
@@ -215,7 +215,7 @@ export default function Shelf() {
                   <button onClick={() => nav(`/book/${b.id}`)} className="group flex w-56 items-center gap-3 rounded-md border bg-card p-2 text-left transition-colors hover:bg-secondary focus-visible:outline-2 focus-visible:outline-accent">
                     <Cover book={b} className="aspect-[3/4] w-11 shrink-0 rounded" />
                     <span className="min-w-0 flex-1">
-                      <span className="block truncate text-sm font-medium group-hover:text-accent">{b.title}</span>
+                      <span className="block truncate text-sm font-medium group-hover:text-accent-strong">{b.title}</span>
                       <span className="mt-0.5 flex justify-between text-[11px] text-muted-foreground">
                         <span>{r.library}</span>
                         <span className="tabular-nums">{pct}%</span>
@@ -282,7 +282,7 @@ export default function Shelf() {
           <AlertDialogFooter>
             <AlertDialogCancel>取消</AlertDialogCancel>
             <AlertDialogAction
-              className="bg-destructive text-primary-foreground hover:bg-destructive/90"
+              className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
               onClick={() => {
                 if (confirmDel) del.mutate(confirmDel.id);
                 setConfirmDel(null);
diff --git a/frontend/src/pages/admin/Users.tsx b/frontend/src/pages/admin/Users.tsx
index 03bc73e..dbcbb74 100644
--- a/frontend/src/pages/admin/Users.tsx
+++ b/frontend/src/pages/admin/Users.tsx
@@ -96,7 +96,7 @@ export default function AdminUsers() {
                       </AlertDialogHeader>
                       <AlertDialogFooter>
                         <AlertDialogCancel>取消</AlertDialogCancel>
-                        <AlertDialogAction className="bg-destructive text-primary-foreground hover:bg-destructive/90" onClick={() => del.mutate(x.id)}>
+                        <AlertDialogAction className="bg-destructive text-destructive-foreground hover:bg-destructive/90" onClick={() => del.mutate(x.id)}>
                           删除
                         </AlertDialogAction>
                       </AlertDialogFooter>
diff --git a/frontend/test/ui.test.ts b/frontend/test/ui.test.ts
deleted file mode 100644
index 3c6dde2..0000000
--- a/frontend/test/ui.test.ts
+++ /dev/null
@@ -1,12 +0,0 @@
-import { describe, expect, it } from "vitest";
-import { formatSize } from "../src/components/ui";
-
-describe("formatSize", () => {
-  it("renders human sizes across units", () => {
-    expect(formatSize(0)).toBe("");
-    expect(formatSize(512)).toBe("512 B");
-    expect(formatSize(2048)).toBe("2.0 KB");
-    expect(formatSize(15 * 1024 * 1024)).toBe("15 MB");
-    expect(formatSize(3.2 * 1024 ** 3)).toBe("3.2 GB");
-  });
-});