diff --git a/app.py b/app.py
index 60dd565..1caa29a 100644
--- a/app.py
+++ b/app.py
@@ -498,12 +498,13 @@ def api_time_distribution(conn):
 def api_shelf(conn):
     """
     书架列表接口（分页）。
-    返回书架中的书籍列表，支持按分类筛选和只看已读完。
+    返回书架中的书籍列表，支持按书名/作者搜索、按分类筛选和只看已读完。
 
     Query Parameters:
         page (int): 页码，默认 1
         per_page (int): 每页数量，默认 60
-        category (str): 分类筛选（模糊匹配）
+        keyword (str): 书名或作者搜索（模糊匹配）
+        category (str): 分类筛选（精确匹配分类名）
         finished (str): "1" 表示只看已读完
 
     Returns:
@@ -511,7 +512,8 @@ def api_shelf(conn):
     """
     page = int(request.args.get("page", 1))
     per_page = int(request.args.get("per_page", 60))
-    category = request.args.get("category", "")
+    keyword = request.args.get("keyword", "").strip()
+    category = request.args.get("category", "").strip()
     finished_only = request.args.get("finished", "0") == "1"
 
     offset = (page - 1) * per_page
@@ -520,9 +522,12 @@ def api_shelf(conn):
     # 构建查询条件
     where_clauses = []
     params = []
+    if keyword:
+        where_clauses.append("(title LIKE %s OR author LIKE %s)")
+        params.extend([f"%{keyword}%", f"%{keyword}%"])
     if category:
-        where_clauses.append("category LIKE %s")
-        params.append(f"%{category}%")
+        where_clauses.append("category = %s")
+        params.append(category)
     if finished_only:
         where_clauses.append("finish_reading=1")
 
diff --git a/static/css/style.css b/static/css/style.css
index 48b3850..e0a777b 100644
--- a/static/css/style.css
+++ b/static/css/style.css
@@ -271,6 +271,103 @@ body {
 [data-theme="dark"] .theme-toggle .icon-moon { display: none; }
 [data-theme="dark"] .theme-toggle { color: var(--toggle-icon-sun); }
 
+/* ===== 顶部常驻搜索框 ===== */
+.global-search-bar {
+    position: sticky;
+    top: 60px;
+    z-index: 90;
+    background: var(--nav-bg);
+    backdrop-filter: blur(12px);
+    -webkit-backdrop-filter: blur(12px);
+    border-bottom: 1px solid var(--border);
+    padding: 10px 0;
+    transition: background-color 0.3s ease, border-color 0.3s ease;
+}
+
+.global-search-wrapper {
+    display: flex;
+    align-items: center;
+    gap: 0;
+    max-width: 600px;
+    margin: 0 auto;
+    position: relative;
+}
+
+.global-search-icon {
+    position: absolute;
+    left: 14px;
+    font-size: 15px;
+    opacity: 0.5;
+    pointer-events: none;
+}
+
+.global-search-input {
+    flex: 1;
+    padding: 9px 16px 9px 40px;
+    border: 1px solid var(--border);
+    border-right: none;
+    border-radius: var(--radius-sm) 0 0 var(--radius-sm);
+    font-size: 14px;
+    background: var(--bg-card);
+    color: var(--text-primary);
+    transition: border-color 0.2s, box-shadow 0.2s;
+}
+
+.global-search-input:focus {
+    outline: none;
+    border-color: var(--accent);
+    box-shadow: 0 0 0 3px var(--accent-bg);
+}
+
+.global-search-btn {
+    padding: 9px 20px;
+    border: 1px solid var(--accent);
+    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
+    background: var(--accent);
+    color: #fff;
+    font-size: 14px;
+    font-weight: 500;
+    cursor: pointer;
+    transition: background 0.2s;
+}
+
+.global-search-btn:hover {
+    background: var(--accent-dark);
+}
+
+/* ===== 书架分类标签 ===== */
+.shelf-categories {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    margin-bottom: 20px;
+}
+
+.shelf-category-tag {
+    padding: 5px 14px;
+    border: 1px solid var(--border);
+    border-radius: 20px;
+    font-size: 13px;
+    color: var(--text-secondary);
+    background: var(--bg-card);
+    cursor: pointer;
+    transition: all 0.2s;
+    white-space: nowrap;
+}
+
+.shelf-category-tag:hover {
+    border-color: var(--accent);
+    color: var(--accent);
+    background: var(--accent-bg);
+}
+
+.shelf-category-tag.active {
+    border-color: var(--accent);
+    color: #fff;
+    background: var(--accent);
+    font-weight: 500;
+}
+
 /* ===== Hero 区 ===== */
 .hero-section {
     position: relative;
@@ -1730,6 +1827,19 @@ body {
     .nav-update {
         display: none;
     }
+    .global-search-wrapper {
+        max-width: 100%;
+    }
+    .shelf-search {
+        width: 140px;
+    }
+    .shelf-categories {
+        gap: 6px;
+    }
+    .shelf-category-tag {
+        font-size: 12px;
+        padding: 4px 10px;
+    }
     .back-to-top {
         bottom: 20px;
         right: 20px;
diff --git a/static/js/app.js b/static/js/app.js
index bb73ef7..555e19d 100644
--- a/static/js/app.js
+++ b/static/js/app.js
@@ -34,9 +34,17 @@ function getChartColors() {
 
 // ===== 工具函数 =====
 
+/**
+ * 升级微信读书封面图 URL 到高清晰度版本。
+ * 微信读书 CDN 的封面图通过文件名前缀区分分辨率：
+ *   t6_ = 低清缩略图（~150px，Retina 屏模糊）
+ *   s_  = 超低清缩略图（~90px，搜索结果常用，更模糊）
+ *   t8_ = 高清版（~500px，适合 2x/3x 屏幕）
+ * 将 t6_ 和 s_ 前缀统一升级为 t8_ 高清版。
+ */
 function hdCover(url) {
     if (!url) return "";
-    return url.replace("/t6_", "/t8_");
+    return url.replace(/\/(t6_|s_)/, "/t8_");
 }
 
 async function fetchAPI(path) {
@@ -147,6 +155,53 @@ function scrollToTop() {
     window.scrollTo({ top: 0, behavior: "smooth" });
 }
 
+// ===== 全局搜索（顶部常驻搜索框） =====
+
+function globalSearch() {
+    const keyword = document.getElementById("globalSearchInput").value.trim();
+    if (!keyword) return;
+
+    // 切换到推荐标签页
+    switchTab("discover");
+    // 切换到搜索子标签
+    switchDiscoverTab("search");
+    // 填入搜索词并执行搜索
+    document.getElementById("searchInput").value = keyword;
+    doSearch();
+}
+
+// ===== 书架分类标签 =====
+
+let shelfCategories = [];
+let shelfActiveCategory = "";  // 空字符串表示"全部"
+
+async function loadShelfCategories() {
+    try {
+        const data = await fetchAPI("/api/shelf?page=1&per_page=1");
+        shelfCategories = data.categories || [];
+        renderShelfCategories();
+    } catch (e) {
+        console.error("加载分类失败:", e);
+    }
+}
+
+function renderShelfCategories() {
+    const container = document.getElementById("shelfCategories");
+    if (!container) return;
+
+    let html = `<button class="shelf-category-tag ${shelfActiveCategory === "" ? "active" : ""}" onclick="filterByCategory('')">全部</button>`;
+    html += shelfCategories
+        .map((cat) => `<button class="shelf-category-tag ${shelfActiveCategory === cat ? "active" : ""}" onclick="filterByCategory('${cat.replace(/'/g, "\\'")}')">${cat}</button>`)
+        .join("");
+    container.innerHTML = html;
+}
+
+function filterByCategory(category) {
+    shelfActiveCategory = category;
+    renderShelfCategories();
+    loadShelf(1);
+}
+
 // ===== 初始化 =====
 
 document.addEventListener("DOMContentLoaded", async () => {
@@ -155,6 +210,7 @@ document.addEventListener("DOMContentLoaded", async () => {
 
     loadOverview();
     loadTopBooks();
+    loadShelfCategories();
     loadShelf(1);
     loadNotebooks();
     loadRecommend(0);
@@ -500,9 +556,11 @@ let shelfCurrentPage = 1;
 
 async function loadShelf(page) {
     shelfCurrentPage = page;
-    const search = document.getElementById("shelfSearch").value;
+    const keyword = document.getElementById("shelfSearch").value.trim();
     const finished = document.getElementById("finishedOnly").checked ? "1" : "0";
-    const params = new URLSearchParams({ page: page, per_page: 60, category: search, finished: finished });
+    const params = new URLSearchParams({ page: page, per_page: 60, finished: finished });
+    if (keyword) params.set("keyword", keyword);
+    if (shelfActiveCategory) params.set("category", shelfActiveCategory);
 
     try {
         const data = await fetchAPI(`/api/shelf?${params}`);
diff --git a/templates/index.html b/templates/index.html
index 0dedfea..4453921 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -51,6 +51,17 @@
         </div>
     </nav>
 
+    <!-- 顶部常驻搜索框 -->
+    <div class="global-search-bar">
+        <div class="container">
+            <div class="global-search-wrapper">
+                <span class="global-search-icon">🔍</span>
+                <input type="text" id="globalSearchInput" class="global-search-input" placeholder="搜索图书..." onkeydown="if(event.key==='Enter')globalSearch()">
+                <button class="global-search-btn" onclick="globalSearch()">搜索</button>
+            </div>
+        </div>
+    </div>
+
     <!-- ===== 主视图（标签页切换） ===== -->
     <main id="mainView">
 
@@ -110,13 +121,14 @@
                 <h2 class="section-title">📚 我的书架</h2>
                 <div class="shelf-controls">
                     <div class="shelf-filters">
-                        <input type="text" id="shelfSearch" class="shelf-search" placeholder="搜索分类...">
+                        <input type="text" id="shelfSearch" class="shelf-search" placeholder="搜索书名、作者...">
                         <label class="filter-checkbox">
                             <input type="checkbox" id="finishedOnly"> 仅看已读完
                         </label>
                     </div>
                     <div class="shelf-info" id="shelfInfo"></div>
                 </div>
+                <div class="shelf-categories" id="shelfCategories"></div>
                 <div class="book-grid" id="bookGrid"></div>
                 <div class="pagination" id="pagination"></div>
             </div>