:root{--bg:#0a1628;--bg2:#0f2140;--card:#122a4d;--card2:#16345e;--accent:#2f7df6;--accent2:#22d3ee;--gold:#f6b93b;--text:#e8f0fb;--muted:#9db4d6;--border:rgba(255,255,255,.1);--radius:14px}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:-apple-system,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text);line-height:1.75;font-size:16px}
a{color:var(--accent2);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%}
.container{max-width:1100px;margin:0 auto;padding:0 20px}
/* ===== 顶栏 ===== */
.site-header{position:sticky;top:0;z-index:99;background:rgba(10,22,40,.88);backdrop-filter:blur(10px);border-bottom:1px solid var(--border)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{font-size:20px;font-weight:800;color:#fff;letter-spacing:.5px}
.brand em{font-style:normal;color:var(--accent2)}
.nav-toggle{display:none;background:none;border:1px solid var(--border);color:var(--text);font-size:20px;padding:6px 12px;border-radius:8px;cursor:pointer}
.site-nav ul{display:flex;list-style:none;gap:2px;flex-wrap:wrap}
.site-nav a{display:block;padding:8px 12px;color:var(--muted);font-size:15px;border-radius:8px}
.site-nav a:hover{color:#fff;background:var(--card);text-decoration:none}
.site-nav a.active{color:#fff;background:linear-gradient(135deg,rgba(47,125,246,.35),rgba(34,211,238,.25));font-weight:600}
/* ===== Hero ===== */
.hero{background:linear-gradient(135deg,#0a1628 0%,#123a6b 55%,#0e5a8a 100%);padding:88px 0 72px;position:relative;overflow:hidden}
.hero::after{content:"";position:absolute;right:-120px;top:-80px;width:420px;height:420px;border-radius:50%;background:radial-gradient(circle,rgba(34,211,238,.18),transparent 70%)}
.hero h1{font-size:40px;line-height:1.3;color:#fff;max-width:760px}
.hero h1 em{font-style:normal;background:linear-gradient(90deg,var(--accent2),var(--gold));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero .lead{margin-top:18px;font-size:18px;color:var(--muted);max-width:680px}
.hero-cta{margin-top:30px;display:flex;gap:14px;flex-wrap:wrap}
.btn{display:inline-block;padding:13px 28px;border-radius:10px;font-weight:700;font-size:16px}
.btn-primary{background:linear-gradient(135deg,var(--accent),var(--accent2));color:#fff;box-shadow:0 8px 24px rgba(47,125,246,.35)}
.btn-primary:hover{filter:brightness(1.1);text-decoration:none}
.btn-ghost{border:1px solid rgba(255,255,255,.35);color:#fff}
.btn-ghost:hover{background:rgba(255,255,255,.08);text-decoration:none}
/* ===== 速答块 ===== */
.quick-answer{margin:26px 0;padding:16px 20px;border-radius:12px;background:linear-gradient(135deg,rgba(246,185,59,.12),rgba(34,211,238,.1));border:1px solid rgba(246,185,59,.4);font-size:16.5px}
.quick-answer strong{color:var(--gold)}
/* ===== 通用 section ===== */
.section{padding:56px 0}
.section.alt{background:var(--bg2)}
.section h2{font-size:28px;color:#fff;margin-bottom:10px}
.section .sec-sub{color:var(--muted);margin-bottom:32px}
.byline{color:var(--muted);font-size:13.5px;margin:14px 0 6px;border-left:3px solid var(--accent);padding-left:10px}
.breadcrumb{font-size:13.5px;color:var(--muted);margin-top:18px}
.breadcrumb a{color:var(--muted)}
/* ===== 卡片 ===== */
.grid{display:grid;gap:20px}
.grid-2{grid-template-columns:repeat(auto-fit,minmax(300px,1fr))}
.grid-3{grid-template-columns:repeat(auto-fit,minmax(250px,1fr))}
.grid-4{grid-template-columns:repeat(auto-fit,minmax(210px,1fr))}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:26px;transition:transform .3s,box-shadow .3s}
.card:hover{transform:translateY(-4px);box-shadow:0 14px 34px rgba(0,0,0,.35)}
.card .icon{font-size:30px;margin-bottom:12px}
.card h3{color:#fff;font-size:19px;margin-bottom:8px}
.card p{color:var(--muted);font-size:15px}
.card .more{display:inline-block;margin-top:14px;font-weight:600}
.stat{text-align:center;padding:28px 16px}
.stat b{display:block;font-size:34px;background:linear-gradient(90deg,var(--accent2),var(--gold));-webkit-background-clip:text;background-clip:text;color:transparent}
.stat span{color:var(--muted);font-size:14px}
/* ===== 表格 ===== */
.table-wrap{overflow-x:auto;border-radius:12px;border:1px solid var(--border)}
table{width:100%;border-collapse:collapse;font-size:15px;min-width:560px}
th{background:var(--bg2);color:#fff;text-align:left;padding:13px 16px;font-size:14.5px}
td{padding:12px 16px;border-top:1px solid var(--border);color:var(--muted)}
td b,td strong{color:var(--text)}
tr:nth-child(even) td{background:rgba(255,255,255,.02)}
/* ===== 时间线 ===== */
.timeline{list-style:none;position:relative;padding-left:36px}
.timeline::before{content:"";position:absolute;left:11px;top:6px;bottom:6px;width:2px;background:linear-gradient(180deg,var(--accent),var(--accent2))}
.timeline li{position:relative;padding:0 0 26px 8px}
.timeline li::before{content:"";position:absolute;left:-33px;top:6px;width:16px;height:16px;border-radius:50%;background:var(--accent2);box-shadow:0 0 0 4px rgba(34,211,238,.18)}
.timeline li b{color:#fff;font-size:17px}
.timeline li p{color:var(--muted);font-size:15px}
/* ===== FAQ 手风琴 ===== */
details.faq{background:var(--card);border:1px solid var(--border);border-radius:12px;margin-bottom:12px;overflow:hidden}
details.faq summary{cursor:pointer;list-style:none;padding:16px 20px;color:#fff;font-weight:600;font-size:16px;position:relative;padding-right:44px}
details.faq summary::-webkit-details-marker{display:none}
details.faq summary::after{content:"+";position:absolute;right:18px;top:50%;transform:translateY(-50%);font-size:22px;color:var(--accent2);transition:transform .25s}
details.faq[open] summary::after{transform:translateY(-50%) rotate(45deg)}
details.faq .faq-a{padding:0 20px 18px;color:var(--muted);font-size:15px}
/* ===== 提示框 / 正文 ===== */
.notice{padding:16px 20px;border-radius:12px;background:rgba(246,185,59,.08);border:1px solid rgba(246,185,59,.35);color:var(--text);font-size:15px;margin:22px 0}
.notice.blue{background:rgba(47,125,246,.08);border-color:rgba(47,125,246,.4)}
.prose h2{font-size:26px;margin:38px 0 14px;color:#fff}
.prose h3{font-size:20px;margin:26px 0 10px;color:var(--accent2)}
.prose p,.prose li{color:var(--muted);font-size:15.5px}
.prose ol,.prose ul{padding-left:24px;margin:12px 0}
.prose li{margin-bottom:8px}
.prose table{margin:16px 0}
/* ===== 计算器 ===== */
.calc{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:28px;max-width:640px}
.calc .row{display:flex;flex-wrap:wrap;gap:14px;margin-bottom:14px}
.calc label{flex:1;min-width:200px;font-size:14px;color:var(--muted)}
.calc input,.calc select{width:100%;margin-top:6px;padding:10px 12px;border-radius:8px;border:1px solid var(--border);background:var(--bg2);color:var(--text);font-size:15px}
.calc-result{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:20px}
.calc-result .box{background:var(--bg2);border-radius:10px;padding:16px;text-align:center}
.calc-result .box span{display:block;font-size:13px;color:var(--muted)}
.calc-result .box b{font-size:24px;color:var(--gold)}
.calc-result .box b.down{color:#4ade80}
/* ===== CTA ===== */
.cta-band{background:linear-gradient(135deg,#123a6b,#0e5a8a);border-radius:18px;padding:44px 36px;text-align:center}
.cta-band h2{color:#fff}
.cta-band p{color:var(--muted);margin:10px 0 22px}
/* ===== 页脚 ===== */
.site-footer{background:#071120;border-top:1px solid var(--border);padding:52px 0 30px;margin-top:0}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:32px}
.site-footer h4{color:#fff;font-size:16px;margin-bottom:14px}
.site-footer ul{list-style:none}
.site-footer li{margin-bottom:8px}
.site-footer a{color:var(--muted);font-size:14px}
.site-footer p{color:var(--muted);font-size:13.5px}
.copyright{margin-top:34px;padding-top:20px;border-top:1px solid var(--border);text-align:center;color:var(--muted);font-size:13px}
/* ===== 入场动画 ===== */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
.reveal.visible{opacity:1;transform:none}
/* ===== 响应式 ===== */
@media(max-width:860px){
 .hero h1{font-size:29px}
 .hero{padding:64px 0 52px}
 .nav-toggle{display:block}
 .site-nav{display:none;width:100%}
 .site-nav.open{display:block;position:absolute;top:64px;left:0;right:0;background:rgba(10,22,40,.98);border-bottom:1px solid var(--border);padding:12px 20px 20px}
 .site-nav ul{flex-direction:column}
 .footer-grid{grid-template-columns:1fr}
 .calc-result{grid-template-columns:1fr}
 .section{padding:44px 0}
}
@media(prefers-reduced-motion:reduce){
 html{scroll-behavior:auto}
 .reveal{opacity:1;transform:none;transition:none}
 .card,.card:hover{transition:none;transform:none}
 details.faq summary::after{transition:none}
}
/* ===== 打印 ===== */
@media print{
 body{background:#fff;color:#000}
 .site-header,.site-footer,.hero-cta,.nav-toggle,.btn,.quick-answer{display:none!important}
 .hero{background:#fff;padding:10px 0}
 .hero h1,.section h2,.card h3{color:#000}
 .card,.details,table,th,td{border-color:#ccc}
 td,p,li,.card p{color:#222}
 .card{background:#fff;box-shadow:none}
 .table-wrap{border-color:#ccc}
}

.reveal{opacity:1!important;transform:none!important}

/* 长标题折行均衡：避免在括号/单位处留下孤字 */
h1 { text-wrap: balance; }