/* ====== Docs 文档系统公共样式（白色主题）====== */
*{margin:0;padding:0;box-sizing:border-box}
:root{
    --bg:#f6f5f2; --panel:#fff; --ink:#1a1a1a; --muted:#6b7280; --line:#e8e8e8;
    --brand:#2563eb; --brand-hover:#1d4ed8; --hover:#f5f5f4;
    --sidebar-w:280px; --toc-w:220px; --header-h:56px;
}
html,body{height:100%}
body{background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;font-size:14px;line-height:1.6}
a{color:var(--brand);text-decoration:none}
a:hover{color:var(--brand-hover)}
img{max-width:100%}

/* 顶部导航 */
.topbar{height:var(--header-h);background:var(--panel);border-bottom:1px solid var(--line);display:flex;align-items:center;padding:0 20px;position:sticky;top:0;z-index:50}
.topbar .brand{font-size:16px;font-weight:600;color:var(--ink);margin-right:28px}
.topbar .brand a{color:inherit}
.topbar nav{display:flex;gap:18px}
.topbar nav a{color:#555;font-size:14px}
.topbar nav a:hover{color:var(--brand)}
.topbar .spacer{flex:1}
.topbar .search{position:relative}
.topbar .search input{width:240px;height:34px;border:1px solid var(--line);border-radius:17px;padding:0 14px 0 34px;background:var(--bg);font-size:13px;outline:none;transition:.15s}
.topbar .search input:focus{border-color:var(--brand);background:#fff;width:300px}
.topbar .search svg{position:absolute;left:12px;top:9px;width:16px;height:16px;color:#9ca3af}
.topbar .user{margin-left:14px;display:flex;align-items:center;gap:8px}
.topbar .user .avatar{width:30px;height:30px;border-radius:50%;background:#e5e7eb;display:inline-flex;align-items:center;justify-content:center;color:#666;font-size:13px;overflow:hidden}
.topbar .user .name{font-size:13px;color:#555;max-width:100px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.btn{display:inline-block;padding:7px 16px;border:1px solid var(--line);background:#fff;color:#333;border-radius:6px;font-size:13px;cursor:pointer}
.btn:hover{background:var(--hover)}
.btn.primary{background:var(--brand);color:#fff;border-color:var(--brand)}
.btn.primary:hover{background:var(--brand-hover)}
.btn.sm{padding:4px 10px;font-size:12px}
.btn.danger{color:#b91c1c;border-color:#f5c6c6}
.btn.danger:hover{background:#fff0f0}

/* 探索页 */
.explore-wrap{max-width:1200px;margin:24px auto;padding:0 20px}
.page-title{font-size:22px;font-weight:600;margin-bottom:16px}
.cat-tabs{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:20px}
.cat-tabs a{padding:5px 14px;border:1px solid var(--line);border-radius:16px;font-size:13px;color:#555;background:#fff}
.cat-tabs a.active{background:var(--brand);color:#fff;border-color:var(--brand)}
.cat-tabs .count{color:#9ca3af;margin-left:4px;font-size:11px}
.book-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px}
.book-card{background:var(--panel);border:1px solid var(--line);border-radius:8px;padding:16px;transition:.15s;display:flex;flex-direction:column}
.book-card:hover{box-shadow:0 4px 14px rgba(0,0,0,0.07);border-color:#ddd;transform:translateY(-1px)}
.book-card .cover{width:100%;height:120px;border-radius:6px;background:linear-gradient(135deg,#e0e7ff,#f0f9ff);display:flex;align-items:center;justify-content:center;color:#6b7280;font-size:13px;margin-bottom:12px;overflow:hidden}
.book-card .cover img{width:100%;height:100%;object-fit:cover}
.book-card h3{font-size:15px;font-weight:600;margin-bottom:6px;color:var(--ink)}
.book-card h3 a{color:inherit}
.book-card .desc{color:var(--muted);font-size:12px;line-height:1.5;flex:1;overflow:hidden;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical}
.book-card .meta{margin-top:10px;font-size:11px;color:#9ca3af;display:flex;justify-content:space-between}
.empty-state{text-align:center;padding:60px 20px;color:var(--muted)}
.empty-state .big{font-size:40px;margin-bottom:8px;opacity:.4}

/* 阅读器三栏 */
.reader{display:flex;height:calc(100vh - var(--header-h));overflow:hidden}
.reader-sidebar{width:var(--sidebar-w);background:var(--panel);border-right:1px solid var(--line);overflow-y:auto;flex-shrink:0}
.reader-main{flex:1;overflow-y:auto}
.reader-toc{width:var(--toc-w);background:var(--panel);border-left:1px solid var(--line);overflow-y:auto;flex-shrink:0;padding:20px 16px}

.book-head{padding:16px 18px;border-bottom:1px solid var(--line)}
.book-head .bt{font-size:15px;font-weight:600;color:var(--ink)}
.book-head .bm{font-size:11px;color:#9ca3af;margin-top:4px}

/* 章节树 */
.doc-tree,.doc-tree ul{list-style:none}
.doc-tree{padding:8px 6px}
.doc-tree ul{padding-left:16px}
.doc-tree li{position:relative}
.doc-tree a{display:block;padding:6px 10px 6px 24px;color:#444;font-size:13px;border-radius:4px;line-height:1.4}
.doc-tree a:hover{background:var(--hover)}
.doc-tree a.active{background:#eff6ff;color:var(--brand);font-weight:500}
.doc-tree .caret{position:absolute;left:6px;top:6px;width:16px;height:16px;cursor:pointer;color:#9ca3af;font-size:10px;display:inline-flex;align-items:center;justify-content:center;user-select:none}
.doc-tree .caret:before{content:"▼";transition:transform .15s;display:inline-block}
.doc-tree .caret-open:before{transform:rotate(0deg)}
.doc-tree .caret.collapsed:before{transform:rotate(-90deg)}
.doc-tree .caret-dot{position:absolute;left:10px;top:10px;width:4px;height:4px;background:#cbd5e1;border-radius:50%}
.doc-tree li.collapsed > ul{display:none}

/* 正文 */
.article{max-width:820px;margin:0 auto;padding:32px 40px 80px}
.article h1{font-size:26px;font-weight:600;margin-bottom:8px;color:var(--ink)}
.article .crumb{font-size:12px;color:#9ca3af;margin-bottom:24px}
.article h2{font-size:20px;font-weight:600;margin:28px 0 12px;padding-bottom:6px;border-bottom:1px solid var(--line)}
.article h3{font-size:16px;font-weight:600;margin:22px 0 10px}
.article h4{font-size:14px;font-weight:600;margin:18px 0 8px}
.article p{margin:10px 0;color:#374151}
.article ul,.article ol{margin:10px 0;padding-left:24px}
.article li{margin:4px 0;color:#374151}
.article code{background:#f3f4f6;padding:2px 6px;border-radius:3px;font-size:13px;font-family:"SF Mono",Menlo,Consolas,monospace;color:#c7254e}
.article pre{background:#1e1e2e;color:#d4d4d4;padding:14px 16px;border-radius:6px;overflow-x:auto;margin:14px 0;font-size:13px}
.article pre code{background:none;color:inherit;padding:0;font-size:13px}
.article blockquote{border-left:3px solid var(--brand);background:#f8fafc;padding:8px 14px;margin:14px 0;color:#555;border-radius:0 4px 4px 0}
.article table{border-collapse:collapse;width:100%;margin:14px 0;font-size:13px;background:#fff}
.article table th,.article table td{border:1px solid var(--line);padding:8px 10px;text-align:left}
.article table tr:first-child td{background:#f9fafb;font-weight:600}
.article img{border-radius:4px;margin:10px 0;border:1px solid var(--line)}
.article .pagenav{display:flex;justify-content:space-between;margin-top:48px;padding-top:18px;border-top:1px solid var(--line)}
.article .pagenav a{font-size:13px}
.article-meta{font-size:12px;color:#9ca3af;margin-top:6px}

/* 右侧 TOC */
.toc-title{font-size:12px;color:#9ca3af;text-transform:uppercase;letter-spacing:.5px;margin-bottom:10px;font-weight:600}
.toc-list{list-style:none}
.toc-list li{margin:6px 0}
.toc-list a{color:#666;font-size:12px;line-height:1.4;display:block;padding:2px 0}
.toc-list a:hover{color:var(--brand)}
.toc-list a.h3{padding-left:14px;font-size:11px;color:#9ca3af}
.toc-list a.active{color:var(--brand);font-weight:500}

/* 搜索结果 */
.search-wrap{max-width:900px;margin:24px auto;padding:0 20px}
.result-item{background:#fff;border:1px solid var(--line);border-radius:8px;padding:14px 16px;margin-bottom:10px}
.result-item h3{font-size:15px;margin-bottom:4px}
.result-item .snippet{color:var(--muted);font-size:13px}
.result-item .where{font-size:11px;color:#9ca3af;margin-top:4px}

/* 分页 */
.pagination{display:flex;gap:6px;justify-content:center;margin-top:24px;flex-wrap:wrap}
.pagination a,.pagination span{padding:6px 12px;border:1px solid var(--line);border-radius:6px;font-size:13px;background:#fff;color:#555}
.pagination a:hover{background:var(--hover)}
.pagination .current{background:var(--brand);color:#fff;border-color:var(--brand)}

/* 提示条 */
.alert{padding:10px 14px;border-radius:6px;font-size:13px;margin-bottom:14px}
.alert.info{background:#eff6ff;border:1px solid #bfdbfe;color:#1e40af}
.alert.success{background:#f0fdf4;border:1px solid #bbf7d0;color:#166534}
.alert.error{background:#fef2f2;border:1px solid #fecaca;color:#991b1b}

/* 响应式 */
@media(max-width:1100px){.reader-toc{display:none}}
@media(max-width:768px){
    .reader-sidebar{width:220px;position:fixed;left:0;top:var(--header-h);bottom:0;z-index:40;transform:translateX(-100%);transition:.2s}
    .reader-sidebar.open{transform:translateX(0)}
    .article{padding:20px 16px 60px}
    .topbar .search input{width:140px}.topbar .search input:focus{width:160px}
    .book-grid{grid-template-columns:1fr}
    .mobile-menu-btn{display:inline-flex!important}
}
.mobile-menu-btn{display:none;width:34px;height:34px;align-items:center;justify-content:center;border:1px solid var(--line);border-radius:6px;background:#fff;margin-right:10px;cursor:pointer}