/* ===== 主站模板：互联网官网版（v7） ===== */
:root{--primary:#0f3460;--primary-2:#16213e;--accent:#00b4d8;--gold:#ffb703;--dark:#0a1128;--text:#1f2937;--muted:#64748b;--bg:#f1f5f9;--card:#ffffff;--line:#e2e8f0;--radius:14px;--shadow:0 10px 30px rgba(2,6,23,.08)}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body.mt-body{font-family:"PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;color:var(--text);background:var(--bg);line-height:1.7}
img{max-width:100%;height:auto}
a{color:var(--primary);text-decoration:none}
a:hover{color:var(--accent)}
.container{max-width:1180px;margin:0 auto;padding:0 20px}
.skip-link{position:absolute;left:-9999px}
.skip-link:focus{left:8px;top:8px;background:#fff;padding:8px 14px;border-radius:8px;z-index:99}
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.94);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:68px}
.brand-logo{height:42px;display:block}
.nav-toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:6px}
.nav-toggle span{width:22px;height:2px;background:var(--dark);transition:.25s}
.nav-toggle.active span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle.active span:nth-child(2){opacity:0}
.nav-toggle.active span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.main-nav{display:flex;list-style:none;gap:4px;align-items:center}
.main-nav-item{position:relative}
.main-nav-link{display:block;padding:10px 15px;border-radius:10px;color:var(--text);font-weight:600;font-size:15px}
.main-nav-link:hover{color:var(--accent);background:rgba(0,180,216,.07)}
.sub-nav{position:absolute;top:100%;left:0;min-width:170px;background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);list-style:none;padding:8px;display:none;flex-direction:column;gap:2px;z-index:5}
.main-nav-item:hover .sub-nav{display:flex}
.sub-nav a{display:block;padding:8px 12px;border-radius:8px;color:var(--text);font-size:14px}
.sub-nav a:hover{background:var(--bg);color:var(--accent)}
/* Hero：深色科技感 */
.hero-internet{background:radial-gradient(1000px 500px at 85% -10%,rgba(0,180,216,.25),transparent 60%),linear-gradient(135deg,#0a1128 0%,#16213e 60%,#0f3460 100%);color:#fff;padding:90px 0}
.hero-internet-inner{display:grid;grid-template-columns:1.2fr .8fr;gap:40px;align-items:center}
.hero-badge{display:inline-block;background:rgba(0,180,216,.15);border:1px solid rgba(0,180,216,.4);color:#7dd3fc;padding:6px 16px;border-radius:999px;font-size:13px;letter-spacing:2px}
.hero-title{font-size:clamp(30px,4.8vw,50px);line-height:1.22;margin:18px 0 14px;font-weight:800}
.hero-desc{color:rgba(255,255,255,.8);font-size:16px;max-width:560px}
.hero-actions{margin-top:28px;display:flex;gap:14px;flex-wrap:wrap}
.code-card{background:rgba(10,17,40,.75);border:1px solid rgba(0,180,216,.35);border-radius:16px;overflow:hidden;box-shadow:0 24px 60px rgba(0,0,0,.45)}
.code-bar{display:flex;gap:6px;padding:12px 14px;background:rgba(255,255,255,.06)}
.code-bar i{width:11px;height:11px;border-radius:50%;background:#ef4444}
.code-bar i:nth-child(2){background:#f59e0b}
.code-bar i:nth-child(3){background:#22c55e}
.code-card pre{padding:20px;color:#7dd3fc;font-family:Consolas,Menlo,monospace;font-size:14px;line-height:2}
/* Buttons */
.btn{display:inline-block;padding:12px 28px;border-radius:12px;font-weight:700;font-size:15px;transition:.2s;border:2px solid transparent}
.btn-primary{background:linear-gradient(135deg,var(--accent),#4895ef);color:#fff}
.btn-primary:hover{filter:brightness(1.08);color:#fff}
.btn-outline-light{border-color:rgba(255,255,255,.5);color:#fff}
.btn-outline-light:hover{background:rgba(255,255,255,.12);color:#fff}
.btn-gold{background:linear-gradient(135deg,#d4a017,#f0c24b);color:#14351f}
.btn-ghost{border-color:rgba(255,255,255,.5);color:#fff}
.btn-ghost:hover{background:rgba(255,255,255,.12);color:#fff}
.btn-ghost-dark{border-color:rgba(255,255,255,.55);color:#fff}
.btn-ghost-dark:hover{background:rgba(255,255,255,.12);color:#fff}
.btn-lg{padding:15px 36px;font-size:16px}
/* Sections */
.page-section{padding:60px 0 8px}
.section-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:24px}
.section-title{font-size:27px;font-weight:800;position:relative;padding-left:16px}
.section-title::before{content:"";position:absolute;left:0;top:7px;bottom:7px;width:6px;border-radius:4px;background:linear-gradient(180deg,var(--accent),#4895ef)}
.section-title::after{content:"";position:absolute;left:16px;bottom:-8px;width:46px;height:3px;background:var(--accent);border-radius:2px}
.section-more{font-size:14px;color:var(--muted)}
.service-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.service-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:30px 24px;box-shadow:var(--shadow);transition:.2s;position:relative;overflow:hidden}
.service-card::before{content:"";position:absolute;left:0;top:0;width:100%;height:3px;background:linear-gradient(90deg,var(--accent),#4895ef);transform:scaleX(0);transform-origin:left;transition:.3s}
.service-card:hover::before{transform:scaleX(1)}
.service-card:hover{transform:translateY(-4px)}
.service-ico{font-size:34px}
.service-card h3{margin:12px 0 8px;font-size:18px;color:var(--primary)}
.service-card p{font-size:14px;color:var(--muted)}
.stat-band{margin-top:56px;background:linear-gradient(135deg,#0a1128,#0f3460);color:#fff;padding:44px 0}
.stat-band-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;text-align:center}
.stat strong{display:block;font-size:30px;color:var(--accent)}
.stat span{font-size:13px;color:rgba(255,255,255,.72)}
.cta-band{margin-top:56px;background:linear-gradient(135deg,var(--accent),#4895ef);color:#fff;padding:52px 0;text-align:center}
.cta-inner h2{font-size:28px;margin-bottom:8px}
.cta-inner p{opacity:.9;margin-bottom:22px}
.cta-band .btn-primary{background:#fff;color:var(--primary)}
.cta-band .btn-primary:hover{color:var(--primary);filter:brightness(.96)}
/* Article cards */
.article-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.article-stream{display:flex;flex-direction:column;gap:16px}
.article-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:.2s;display:flex;flex-direction:column}
.article-stream .article-card{flex-direction:row}
.article-card:hover{transform:translateY(-3px);box-shadow:0 16px 34px rgba(2,6,23,.12)}
.article-thumb{flex:0 0 auto;height:150px;display:flex;align-items:center;justify-content:center;font-size:40px;background:linear-gradient(135deg,rgba(0,180,216,.1),rgba(72,149,239,.14));overflow:hidden}
.article-stream .article-thumb{width:210px;height:auto;min-height:120px}
.article-thumb img{width:100%;height:100%;object-fit:cover}
.article-body{padding:18px;display:flex;flex-direction:column;gap:8px;flex:1}
.article-meta{display:flex;gap:14px;font-size:13px;color:var(--muted)}
.article-title{font-size:17px;line-height:1.45}
.article-title a{color:var(--dark)}
.article-title a:hover{color:var(--accent)}
.article-summary{font-size:14px;color:var(--muted);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.article-more{font-size:14px;font-weight:600;margin-top:auto;color:var(--accent)}
.pagination{display:flex;gap:8px;justify-content:center;margin:26px 0;flex-wrap:wrap}
.pagination a,.pagination .current{padding:8px 14px;border-radius:10px;border:1px solid var(--line);background:#fff;font-size:14px;color:var(--text)}
.pagination .current{background:linear-gradient(135deg,var(--accent),#4895ef);color:#fff;border-color:transparent;font-weight:700}
/* 内容布局 */
.page-hero{padding:34px 0 0}
.content-layout{display:grid;grid-template-columns:1fr 300px;gap:26px;padding-top:22px;padding-bottom:48px}
.page-title{font-size:30px;font-weight:800;margin-top:10px;color:var(--primary)}
.page-subtitle{color:var(--muted);margin:6px 0 20px}
.breadcrumb{font-size:13px;color:var(--muted)}
.crumb-sep{margin:0 8px}
.content-aside{display:flex;flex-direction:column;gap:18px}
.sidebar-box{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow)}
.sidebar-title{font-size:16px;margin-bottom:12px;padding-bottom:10px;border-bottom:1px solid var(--line);color:var(--primary)}
.sidebar-list-wrap,.sidebar-list{display:flex;flex-direction:column;gap:2px}
.sidebar-article-item{padding:8px 4px;border-bottom:1px dashed var(--line);font-size:14px;line-height:1.55}
.sidebar-article-item:last-child{border-bottom:0}
.sidebar-category-list{list-style:none;display:flex;flex-direction:column;gap:2px}
.sidebar-category-list a{display:flex;justify-content:space-between;padding:9px 6px;border-radius:8px;color:var(--text);font-size:14px}
.sidebar-category-list a:hover{background:var(--bg);color:var(--accent)}
.sidebar-category-count{background:linear-gradient(135deg,var(--accent),#4895ef);color:#fff;border-radius:999px;font-size:12px;padding:0 8px;line-height:18px}
/* Detail */
.detail-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:30px;box-shadow:var(--shadow);margin-top:16px}
.detail-title{font-size:26px;line-height:1.4;color:var(--primary)}
.detail-meta{display:flex;gap:18px;color:var(--muted);font-size:13px;margin:12px 0 20px;flex-wrap:wrap}
.detail-cover{margin-bottom:20px}
.detail-cover:empty{display:none}
.detail-cover img{border-radius:12px;width:100%}
.article-content{font-size:15.5px;color:#374151;word-break:break-word}
.article-content p{margin:12px 0}
.article-content img{border-radius:10px;margin:10px auto}
.article-content h1,.article-content h2,.article-content h3{margin:22px 0 10px;color:var(--primary)}
.article-content ul,.article-content ol{padding-left:24px;margin:10px 0}
.article-content table{width:100%;border-collapse:collapse;margin:14px 0}
.article-content td,.article-content th{border:1px solid var(--line);padding:8px 10px}
.article-tags-row{margin-top:22px;display:flex;gap:8px;flex-wrap:wrap}
.article-tags-row:empty{display:none}
.article-tag{background:rgba(0,180,216,.12);color:#0e7490;border-radius:999px;padding:3px 12px;font-size:13px}
.article-nav-row{margin-top:22px;display:flex;flex-direction:column;gap:10px}
.article-nav-row:empty{display:none}
.article-nav-prev,.article-nav-next{background:var(--bg);border-radius:10px;padding:12px 16px;font-size:14px}
.article-nav-prev span,.article-nav-next span{color:var(--muted);display:block;font-size:12px}
/* Prose / FAQ / Contact */
.prose-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:30px;box-shadow:var(--shadow);margin-top:18px}
.faq-list{margin-top:18px;display:flex;flex-direction:column;gap:12px}
.faq-item{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:4px 18px}
.faq-item summary{cursor:pointer;font-weight:700;padding:12px 0;font-size:15.5px}
.faq-item div{padding:0 0 14px;color:var(--muted);font-size:14.5px}
.faq-item p{margin:6px 0}
.contact-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:20px}
.contact-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px;text-align:center;box-shadow:var(--shadow)}
.contact-ico{font-size:32px}
.contact-card h3{margin:8px 0 4px;font-size:16px}
.contact-card p{color:var(--muted);font-size:14px}
/* Footer */
.site-footer{background:#0a1128;color:rgba(255,255,255,.78);margin-top:64px;padding:52px 0 0}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1.2fr;gap:34px;padding-bottom:34px}
.footer-col h4{color:#fff;margin-bottom:14px;font-size:16px}
.footer-about{font-size:13.5px;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.footer-contact-line{font-size:13.5px;margin-top:6px}
.footer-links{list-style:none;display:flex;flex-direction:column;gap:8px}
.footer-links a{color:rgba(255,255,255,.75);font-size:13.5px}
.footer-links a:hover{color:var(--accent)}
.friend-links-area{border-top:1px solid rgba(255,255,255,.1);padding:18px 0}
.friend-links-title{font-size:14px;color:#fff;margin-bottom:10px}
.friend-links{display:flex;flex-wrap:wrap;gap:10px 18px}
.friend-links a{color:rgba(255,255,255,.66);font-size:13px}
.friend-links a:hover{color:var(--accent)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding:16px 0 18px;display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;font-size:13px}
.sitemap-links{display:flex;gap:10px;align-items:center}
.sitemap-links a{color:rgba(255,255,255,.66)}
.back-top{position:fixed;right:22px;bottom:26px;width:44px;height:44px;border-radius:50%;border:0;background:linear-gradient(135deg,var(--accent),#4895ef);color:#fff;font-size:18px;cursor:pointer;opacity:0;pointer-events:none;transition:.25s;z-index:60}
.back-top.show{opacity:1;pointer-events:auto}
/* Responsive */
@media (max-width:960px){
  .hero-internet-inner{grid-template-columns:1fr}
  .hero-visual{display:none}
  .service-grid{grid-template-columns:repeat(2,1fr)}
  .article-grid{grid-template-columns:repeat(2,1fr)}
  .content-layout{grid-template-columns:1fr}
  .stat-band-grid{grid-template-columns:repeat(2,1fr);gap:22px}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media (max-width:860px){
  .nav-toggle{display:flex}
  .site-nav{position:absolute;top:100%;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);display:none;padding:10px 16px 16px;box-shadow:var(--shadow)}
  .site-nav.nav-open{display:block}
  .main-nav{flex-direction:column;align-items:stretch;gap:2px}
  .sub-nav{position:static;display:flex;box-shadow:none;border:0;padding-left:18px}
}
@media (max-width:600px){
  .service-grid,.article-grid,.contact-cards{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .article-stream .article-card{flex-direction:column}
  .article-stream .article-thumb{width:100%;height:170px}
  .footer-bottom{flex-direction:column;text-align:center}
}