:root{--primary:#2563eb;--primary-dark:#1d4ed8;--accent:#3b82f6;--bg:#f8fafc;--bg-white:#fff;--text:#1e293b;--text-light:#64748b;--text-lighter:#94a3b8;--border:#e2e8f0;--shadow:0 1px 3px rgba(0,0,0,.1);--shadow-md:0 4px 6px -1px rgba(0,0,0,.1);--shadow-lg:0 10px 15px -3px rgba(0,0,0,.1);--radius:8px;--radius-lg:12px}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;color:var(--text);background:var(--bg);line-height:1.6;font-size:16px}
a{color:var(--primary);text-decoration:none;transition:color .2s}
a:hover{color:var(--primary-dark)}
img{max-width:100%;height:auto;vertical-align:middle}
ul,ol{list-style:none}
.w1200{max-width:1200px;margin:0 auto;padding:0 20px}

/* Header */
.site-header{background:var(--bg-white);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.site-logo{font-size:22px;font-weight:800;color:var(--text)}
.site-logo span{color:var(--primary)}
.main-nav{display:flex;gap:4px}
.main-nav a{padding:8px 14px;border-radius:6px;font-size:14px;font-weight:500;color:var(--text-light);transition:all .2s}
.main-nav a:hover,.main-nav a.active{background:var(--primary);color:#fff}
.search-box{position:relative}
.search-box input{width:200px;padding:8px 12px 8px 36px;border:1px solid var(--border);border-radius:20px;font-size:14px;background:var(--bg);outline:none;transition:border .2s}
.search-box input:focus{border-color:var(--primary)}
.search-box svg{position:absolute;left:12px;top:50%;transform:translateY(-50%);width:16px;height:16px;color:var(--text-lighter)}
.menu-toggle{display:none;background:none;border:none;cursor:pointer;padding:8px}
.menu-toggle span{display:block;width:24px;height:2px;background:var(--text);margin:5px 0;transition:.3s}

/* Hero */
.hero{background:linear-gradient(135deg,#1e3a5f 0%,#2563eb 50%,#3b82f6 100%);color:#fff;padding:80px 0 60px;text-align:center;position:relative;overflow:hidden}
.hero::after{content:'';position:absolute;bottom:-2px;left:0;right:0;height:60px;background:var(--bg);clip-path:ellipse(55% 100% at 50% 100%)}
.hero h1{font-size:48px;font-weight:800;margin-bottom:12px;letter-spacing:-1px}
.hero p{font-size:20px;opacity:.85;margin-bottom:32px}
.hero-links{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.hero-links a{background:rgba(255,255,255,.15);backdrop-filter:blur(4px);padding:10px 20px;border-radius:24px;color:#fff;font-size:14px;font-weight:500;border:1px solid rgba(255,255,255,.2);transition:all .2s}
.hero-links a:hover{background:rgba(255,255,255,.25);color:#fff}

/* Category Cards */
.cat-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin:-40px auto 40px;position:relative;z-index:2}
.cat-card{background:var(--bg-white);border-radius:var(--radius-lg);padding:28px 20px;text-align:center;box-shadow:var(--shadow-md);transition:transform .2s,box-shadow .2s}
.cat-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.cat-card-icon{width:56px;height:56px;margin:0 auto 14px;background:linear-gradient(135deg,var(--primary),var(--accent));border-radius:14px;display:flex;align-items:center;justify-content:center;font-size:28px}
.cat-card h3{font-size:16px;font-weight:700;margin-bottom:6px}
.cat-card p{font-size:13px;color:var(--text-light);line-height:1.5}

/* Section */
.section{padding:50px 0}
.section-title{font-size:28px;font-weight:800;margin-bottom:8px}
.section-sub{color:var(--text-light);margin-bottom:30px;font-size:15px}

/* FAQ */
.faq-list{display:flex;flex-direction:column;gap:10px}
.faq-item{background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}
.faq-q{padding:16px 20px;font-weight:600;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-size:15px}
.faq-q:hover{background:var(--bg)}
.faq-q::after{content:'+';font-size:20px;color:var(--text-lighter);transition:transform .2s}
.faq-item.open .faq-q::after{transform:rotate(45deg)}
.faq-a{padding:0 20px;max-height:0;overflow:hidden;transition:all .3s;color:var(--text-light);font-size:14px;line-height:1.7}
.faq-item.open .faq-a{padding:0 20px 16px;max-height:500px}

/* Tools */
.tools-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:20px}
.tool-card{background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);padding:30px;text-align:center;transition:box-shadow .2s}
.tool-card:hover{box-shadow:var(--shadow-md)}
.tool-card h3{font-size:18px;font-weight:700;margin-bottom:8px}
.tool-card p{color:var(--text-light);font-size:14px}

/* Article List */
.article-list{display:flex;flex-direction:column;gap:20px}
.article-item{display:flex;gap:20px;background:var(--bg-white);border-radius:var(--radius-lg);overflow:hidden;box-shadow:var(--shadow);transition:box-shadow .2s}
.article-item:hover{box-shadow:var(--shadow-md)}
.article-thumb{width:280px;min-height:180px;flex-shrink:0;overflow:hidden}
.article-thumb img{width:100%;height:100%;object-fit:cover;transition:transform .3s}
.article-item:hover .article-thumb img{transform:scale(1.05)}
.article-info{padding:20px;display:flex;flex-direction:column;justify-content:center;flex:1}
.article-info h2{font-size:18px;font-weight:700;margin-bottom:8px;line-height:1.4}
.article-info h2 a{color:var(--text)}
.article-info h2 a:hover{color:var(--primary)}
.article-meta{font-size:13px;color:var(--text-lighter);margin-bottom:10px}
.article-excerpt{font-size:14px;color:var(--text-light);line-height:1.7;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}

/* Category Page */
.cat-header{background:linear-gradient(135deg,#1e3a5f,#2563eb);color:#fff;padding:50px 0 40px;text-align:center}
.cat-header h1{font-size:36px;font-weight:800;margin-bottom:8px}
.cat-header p{opacity:.8;font-size:16px}
.breadcrumb{padding:14px 0;font-size:13px;color:var(--text-lighter)}
.breadcrumb a{color:var(--text-light)}
.breadcrumb a:hover{color:var(--primary)}
.cat-content{display:grid;grid-template-columns:1fr 300px;gap:30px;padding:30px 0}
.sidebar{display:flex;flex-direction:column;gap:20px}
.sidebar-box{background:var(--bg-white);border-radius:var(--radius-lg);padding:20px;box-shadow:var(--shadow)}
.sidebar-box h3{font-size:16px;font-weight:700;margin-bottom:14px;padding-bottom:10px;border-bottom:2px solid var(--primary)}
.sidebar-list a{display:block;padding:8px 0;font-size:14px;color:var(--text-light);border-bottom:1px solid var(--border)}
.sidebar-list a:last-child{border:none}
.sidebar-list a:hover{color:var(--primary)}
.tag-cloud{display:flex;flex-wrap:wrap;gap:8px}
.tag-item{display:inline-block;padding:4px 12px;font-size:13px;background:var(--bg);color:var(--text-light);border-radius:20px;border:1px solid var(--border);transition:all .2s}
.tag-item:hover{background:var(--primary);color:#fff;border-color:var(--primary)}
.ad-slot{border-radius:var(--radius);text-align:center;min-height:1px}
.ad-slot:empty{display:none}

/* Article Detail */
.article-layout{display:grid;grid-template-columns:1fr 300px;gap:30px;padding:30px 0}
.article-detail{padding:0}
.article-detail h1{font-size:32px;font-weight:800;line-height:1.3;margin-bottom:16px}
.article-detail .meta{display:flex;gap:16px;font-size:13px;color:var(--text-lighter);margin-bottom:20px;padding-bottom:20px;border-bottom:1px solid var(--border)}
.toc{background:var(--bg);border-radius:var(--radius-lg);padding:20px 24px;margin-bottom:30px}
.toc-title{font-weight:700;margin-bottom:10px;font-size:15px}
.toc a{display:block;padding:4px 0;font-size:14px;color:var(--text-light)}
.toc a:hover{color:var(--primary)}
.toc .toc-h3{padding-left:16px}
.article-body{font-size:16px;line-height:1.8;color:var(--text)}
.article-body h2{font-size:24px;font-weight:700;margin:36px 0 16px;padding-bottom:8px;border-bottom:2px solid var(--border)}
.article-body h3{font-size:20px;font-weight:600;margin:28px 0 12px}
.article-body p{margin-bottom:16px}
.article-body img{border-radius:var(--radius);margin:16px 0}
.article-body ul,.article-body ol{margin:16px 0;padding-left:24px}
.article-body ul{list-style:disc}
.article-body ol{list-style:decimal}
.article-body li{margin-bottom:8px}
.article-body table{width:100%;border-collapse:collapse;margin:16px 0}
.article-body th,.article-body td{padding:10px 14px;border:1px solid var(--border);text-align:left;font-size:14px}
.article-body th{background:var(--bg);font-weight:600}

/* Related Articles */
.related-articles{margin-top:40px;padding-top:30px;border-top:1px solid var(--border)}
.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:20px}
.related-card{background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;transition:box-shadow .2s}
.related-card:hover{box-shadow:var(--shadow-md)}
.related-card img{width:100%;height:140px;object-fit:cover}
.related-card h3{padding:12px;font-size:14px;font-weight:600;line-height:1.4}
.related-card h3 a{color:var(--text)}

/* Prev/Next */
.prev-next{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:30px}
.prev-next a{display:block;padding:16px;background:var(--bg);border-radius:var(--radius);font-size:14px;color:var(--text-light)}
.prev-next a:hover{background:var(--border)}
.prev-next .label{font-size:12px;color:var(--text-lighter);margin-bottom:4px}

/* Pagination */
.pages{display:flex;justify-content:center;gap:6px;padding:30px 0}
.pages a,.pages span{display:inline-flex;align-items:center;justify-content:center;min-width:36px;height:36px;padding:0 10px;border-radius:6px;font-size:14px;border:1px solid var(--border);color:var(--text-light);background:var(--bg-white)}
.pages a:hover{border-color:var(--primary);color:var(--primary)}
.pages .current,.pages span.current{background:var(--primary);color:#fff;border-color:var(--primary)}

/* Footer */
.site-footer{background:#1e293b;color:#cbd5e1;padding:50px 0 0;margin-top:60px}
.footer-inner{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;padding-bottom:40px}
.footer-brand{font-size:14px;line-height:1.7}
.footer-brand .logo{font-size:22px;font-weight:800;color:#fff;margin-bottom:12px}
.footer-brand .logo span{color:var(--accent)}
.footer-links h4{color:#fff;font-size:14px;font-weight:600;margin-bottom:14px}
.footer-links a{display:block;padding:4px 0;font-size:13px;color:#94a3b8;transition:color .2s}
.footer-links a:hover{color:#fff}
.footer-bottom{border-top:1px solid #334155;padding:16px 0;text-align:center;font-size:13px;color:#64748b}

/* Tags */
.tag-list{display:flex;flex-wrap:wrap;gap:8px;margin-top:10px}
.tag-list a{padding:4px 12px;background:var(--bg);border-radius:20px;font-size:13px;color:var(--text-light);border:1px solid var(--border);transition:all .2s}
.tag-list a:hover{background:var(--primary);color:#fff;border-color:var(--primary)}

/* Responsive */
@media(max-width:1024px){
.cat-cards{grid-template-columns:repeat(2,1fr)}
.cat-content{grid-template-columns:1fr}
.article-layout{grid-template-columns:1fr}
.sidebar{display:none}
.footer-inner{grid-template-columns:1fr 1fr}
.related-grid{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:768px){
.header-inner{flex-wrap:wrap;height:auto;padding:10px 0}
.main-nav{display:none;width:100%;flex-direction:column;padding:10px 0}
.main-nav.show{display:flex}
.menu-toggle{display:block}
.search-box{display:none}
.hero h1{font-size:28px}
.hero p{font-size:16px}
.cat-cards{grid-template-columns:1fr}
.article-thumb{width:120px;min-height:100px}
.article-detail h1{font-size:24px}
.related-grid{grid-template-columns:1fr}
.prev-next{grid-template-columns:1fr}
.tools-grid{grid-template-columns:1fr}
.footer-inner{grid-template-columns:1fr}
}