:root{
  --primary:#2563eb; --primary-d:#1d4ed8; --primary-l:#dbeafe;
  --accent:#f59e0b; --accent-l:#fef3c7;
  --green:#16a34a; --red:#dc2626; --gray:#6b7280;
  --text:#1e293b; --text2:#475569; --text3:#94a3b8;
  --bg:#f8fafc; --white:#fff; --border:#e2e8f0; --border-l:#f1f5f9;
  --radius:8px; --radius-l:12px; --shadow:0 1px 3px rgba(0,0,0,.08); --shadow-l:0 4px 12px rgba(0,0,0,.1);
}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'PingFang SC','Microsoft YaHei',sans-serif;color:var(--text);background:var(--bg);font-size:15px;line-height:1.7}
a{color:var(--primary);text-decoration:none;transition:color .2s}
a:hover{color:var(--primary-d)}
img{max-width:100%;height:auto}
.container{max-width:1200px;margin:0 auto;padding:0 20px}
.container-sm{max-width:900px;margin:0 auto;padding:0 20px}
/* Header */
.site-header{background:var(--white);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100;box-shadow:var(--shadow)}
.site-header .container{display:flex;align-items:center;height:64px;gap:32px}
.logo{font-size:22px;font-weight:700;color:var(--primary);white-space:nowrap}
.logo span{color:var(--accent)}
.main-nav{display:flex;gap:24px;flex:1}
.main-nav a{color:var(--text2);font-size:15px;font-weight:500;padding:8px 0;position:relative}
.main-nav a:hover,.main-nav a.active{color:var(--primary)}
.main-nav a.active::after{content:'';position:absolute;bottom:0;left:0;right:0;height:2px;background:var(--primary);border-radius:1px}
.header-search{position:relative;width:240px}
.header-search input{width:100%;padding:8px 36px 8px 12px;border:1px solid var(--border);border-radius:20px;font-size:14px;outline:none;transition:border-color .2s}
.header-search input:focus{border-color:var(--primary)}
.header-search button{position:absolute;right:8px;top:50%;transform:translateY(-50%);background:none;border:none;cursor:pointer;color:var(--text3);padding:4px}
/* Breadcrumb */
.breadcrumb{display:flex;align-items:center;gap:8px;padding:16px 0;font-size:13px;color:var(--text3);flex-wrap:wrap}
.breadcrumb a{color:var(--text3)}
.breadcrumb a:hover{color:var(--primary)}
.breadcrumb .sep{color:var(--text3)}
/* Cards */
.card{background:var(--white);border:1px solid var(--border);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow)}
.card-l{background:var(--white);border:1px solid var(--border);border-radius:var(--radius-l);padding:24px;box-shadow:var(--shadow-l)}
/* Grid */
.grid{display:grid;gap:20px}
.grid-2{grid-template-columns:1fr 1fr}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.grid-auto{grid-template-columns:repeat(auto-fill,minmax(260px,1fr))}
@media(max-width:768px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr}}
/* Brand card */
.brand-card{background:var(--white);border:1px solid var(--border);border-radius:var(--radius-l);overflow:hidden;transition:box-shadow .2s,transform .2s}
.brand-card:hover{box-shadow:var(--shadow-l);transform:translateY(-2px)}
.brand-card .img{width:100%;height:160px;background:var(--border-l);display:flex;align-items:center;justify-content:center;overflow:hidden}
.brand-card .img img{width:100%;height:100%;object-fit:cover}
.brand-card .body{padding:16px}
.brand-card .title{font-size:16px;font-weight:600;margin-bottom:8px}
.brand-card .title .verified{display:inline-block;width:16px;height:16px;background:var(--primary);color:#fff;border-radius:50%;font-size:10px;text-align:center;line-height:16px;margin-left:4px}
.brand-card .meta{font-size:13px;color:var(--text3);display:flex;gap:12px;flex-wrap:wrap}
.brand-card .meta span{display:flex;align-items:center;gap:4px}
/* Article list */
.article-item{display:flex;gap:16px;padding:16px 0;border-bottom:1px solid var(--border-l)}
.article-item:last-child{border-bottom:none}
.article-item .thumb{width:160px;height:100px;border-radius:var(--radius);overflow:hidden;flex-shrink:0;background:var(--border-l)}
.article-item .thumb img{width:100%;height:100%;object-fit:cover}
.article-item .info{flex:1;min-width:0}
.article-item .info h3{font-size:17px;font-weight:600;margin-bottom:8px}
.article-item .info h3 a{color:var(--text)}
.article-item .info h3 a:hover{color:var(--primary)}
.article-item .info .summary{font-size:14px;color:var(--text3);line-height:1.6;margin-bottom:8px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.article-item .info .meta{font-size:13px;color:var(--text3);display:flex;gap:16px}
/* Section title */
.section-title{display:flex;align-items:center;justify-content:space-between;margin-bottom:20px}
.section-title h2{font-size:20px;font-weight:600;color:var(--text)}
.section-title h2 span{color:var(--primary)}
.section-title .more{font-size:14px;color:var(--text3)}
/* Stats */
.stats-bar{display:flex;gap:32px;padding:24px 0;flex-wrap:wrap}
.stat-item{text-align:center;flex:1;min-width:120px}
.stat-item .num{font-size:32px;font-weight:700;color:var(--primary)}
.stat-item .label{font-size:14px;color:var(--text3);margin-top:4px}
/* Filter bar */
.filter-bar{display:flex;align-items:center;gap:12px;padding:16px;background:var(--white);border:1px solid var(--border);border-radius:var(--radius);margin-bottom:20px;flex-wrap:wrap}
.filter-bar .label{font-size:14px;color:var(--text3);font-weight:500}
.filter-bar select,.filter-bar input{padding:6px 12px;border:1px solid var(--border);border-radius:6px;font-size:14px;background:var(--white)}
.filter-bar .btn{padding:6px 16px}
/* Pagination */
.pagination{display:flex;align-items:center;justify-content:center;gap:4px;padding:24px 0}
.pagination a,.pagination span{display:inline-block;min-width:36px;height:36px;line-height:36px;text-align:center;padding:0 8px;border:1px solid var(--border);border-radius:6px;color:var(--text2);font-size:14px}
.pagination a:hover{border-color:var(--primary);color:var(--primary)}
.pagination .current{background:var(--primary);color:#fff;border-color:var(--primary)}
.pagination .disabled{color:var(--text3);cursor:not-allowed}
/* Badges */
.badge{display:inline-block;padding:2px 8px;border-radius:4px;font-size:12px;font-weight:500}
.badge-verified{background:var(--primary-l);color:var(--primary-d)}
.badge-unverified{background:var(--border-l);color:var(--text3)}
.badge-ai{background:var(--accent-l);color:#92400e}
/* Footer */
.site-footer{background:#1e293b;color:#94a3b8;padding:40px 0 20px;margin-top:60px}
.site-footer .grid{grid-template-columns:2fr 1fr 1fr 1fr}
.footer-links a{color:#94a3b8;font-size:14px;line-height:2.4}
.footer-links a:hover{color:#fff}
.footer-copy{text-align:center;padding-top:24px;border-top:1px solid #334155;margin-top:24px;font-size:13px}
@media(max-width:768px){.site-footer .grid{grid-template-columns:1fr}.header-search{display:none}.main-nav{overflow-x:auto}}
/* Article content */
.article-content{font-size:16px;line-height:1.8;color:var(--text)}
.article-content h2{font-size:22px;margin:24px 0 12px;font-weight:600}
.article-content h3{font-size:18px;margin:20px 0 10px;font-weight:600}
.article-content p{margin:12px 0}
.article-content strong{color:var(--primary)}
.article-content table{width:100%;border-collapse:collapse;margin:16px 0}
.article-content table th{background:var(--border-l);padding:10px;border:1px solid var(--border);font-weight:600}
.article-content table td{padding:10px;border:1px solid var(--border)}
.article-content img{border-radius:var(--radius);margin:12px 0}
/* Q&A */
.qa-item{padding:16px 0;border-bottom:1px solid var(--border-l)}
.qa-item:last-child{border-bottom:none}
.qa-item .q{font-size:16px;font-weight:600;margin-bottom:8px;color:var(--text)}
.qa-item .q::before{content:'Q';display:inline-block;width:24px;height:24px;background:var(--primary);color:#fff;border-radius:50%;text-align:center;line-height:24px;font-size:14px;margin-right:8px}
.qa-item .a{font-size:15px;color:var(--text2);line-height:1.8;padding-left:32px}
.qa-item .a::before{content:'A';display:inline-block;width:24px;height:24px;background:var(--accent);color:#fff;border-radius:50%;text-align:center;line-height:24px;font-size:14px;margin-right:8px}