:root{--ink:#14232b;--muted:#5b6b73;--line:#dfe6e9;--bg:#fbfaf7;--card:#fff;--brand:#0f4c5c;--brand-2:#e36414;--soft:#eef5f6;--wa:#1fa855;--r:14px;--w:1120px}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;font:17px/1.65 system-ui,-apple-system,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;color:var(--ink);background:var(--bg)}
a{color:var(--brand)}
img{max-width:100%;height:auto}
.wrap{max-width:var(--w);margin:0 auto;padding:0 16px}
.skip{position:absolute;left:-999px}.skip:focus{left:8px;top:8px;background:#fff;padding:8px;z-index:99}
.small{font-size:.875rem}.muted{color:var(--muted)}
h1,h2,h3{line-height:1.25;letter-spacing:-.01em}
h1{font-size:clamp(1.8rem,4.2vw,2.8rem);margin:.2em 0 .3em}
h2{font-size:clamp(1.35rem,2.6vw,1.8rem);margin:1.8em 0 .5em}
h3{font-size:1.15rem;margin:1.4em 0 .4em}
.btn{display:inline-block;padding:.75em 1.2em;border-radius:999px;font-weight:600;text-decoration:none;border:0;cursor:pointer;font-size:1rem}
.btn-wa{background:var(--wa);color:#fff}.btn-wa:hover{filter:brightness(1.07)}
.btn-ghost{background:transparent;color:#fff;border:1.5px solid rgba(255,255,255,.6)}
.btn-sm{padding:.5em .95em;font-size:.9rem}
.site-head{position:sticky;top:0;z-index:20;background:rgba(251,250,247,.94);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.head-row{display:flex;align-items:center;gap:16px;min-height:62px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;text-decoration:none;color:var(--ink);white-space:nowrap}
.logo{display:grid;place-items:center;width:34px;height:34px;border-radius:9px;background:var(--brand);color:#fff;font-size:.85rem}
.nav{display:flex;gap:18px;margin-left:auto;font-size:.95rem}
.nav a{text-decoration:none;color:var(--ink)}.nav a:hover{color:var(--brand)}
@media (max-width:860px){.nav{display:none}.head-row .btn{margin-left:auto}}
.crumbs{font-size:.85rem;color:var(--muted);padding-top:14px}.crumbs a{color:var(--muted)}
.page-head{padding:18px 16px 4px}
.lede{font-size:1.15rem;color:var(--muted);max-width:760px}
.content{padding-bottom:40px}
.article{max-width:800px}
.article p,.article li{max-width:72ch}
.answer{background:var(--soft);border-left:4px solid var(--brand);padding:16px 18px;border-radius:0 var(--r) var(--r) 0;margin:12px 0 8px;font-size:1.05rem}
.facts table,.content table{width:100%;border-collapse:collapse;background:var(--card);border-radius:var(--r);overflow:hidden;border:1px solid var(--line);font-size:.95rem}
.facts th,.facts td,.content th,.content td{padding:10px 14px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
.facts th{width:40%;color:var(--muted);font-weight:600}
.content thead th{background:var(--soft)}
.table-scroll{overflow-x:auto}
.faq details{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:0 16px;margin:10px 0}
.faq summary{cursor:pointer;font-weight:600;padding:14px 0;list-style-position:outside}
.faq details>div{padding-bottom:12px}
.sources li{font-size:.92rem}
.author{display:flex;gap:14px;border-top:1px solid var(--line);margin-top:36px;padding-top:18px}
.avatar{flex:none;width:48px;height:48px;border-radius:50%;background:var(--brand);color:#fff;display:grid;place-items:center;font-weight:700}
.author p{margin:.2em 0}
.callout{background:#fff4ec;border:1px solid #f6d3bb;border-radius:var(--r);padding:14px 18px;margin:18px 0}
/* hero */
.hero{background:linear-gradient(135deg,#0b3b48 0%,#0f4c5c 55%,#1b6a73 100%);color:#fff;padding:56px 0 64px}
.hero h1{color:#fff;max-width:820px}
.hero p{font-size:1.15rem;max-width:680px;color:#d9eef0}
.hero .ctas{display:flex;gap:12px;flex-wrap:wrap;margin-top:22px}
.hero .stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:14px;margin-top:36px;max-width:820px}
.stat{background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.15);border-radius:var(--r);padding:12px 14px}
.stat b{display:block;font-size:1.35rem}
.stat span{font-size:.85rem;color:#cfe5e8}
/* cards */
.section{padding:44px 0}
.section h2{margin-top:0}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:18px;text-decoration:none;color:var(--ink);display:block;transition:transform .15s,box-shadow .15s}
.card:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(15,76,92,.1)}
.card h3{margin:0 0 6px;color:var(--brand)}
.card p{margin:0;font-size:.95rem;color:var(--muted)}
.tag{display:inline-block;font-size:.75rem;font-weight:600;background:var(--soft);color:var(--brand);padding:2px 8px;border-radius:999px;margin-bottom:8px}
.steps{counter-reset:s;list-style:none;padding:0}
.steps li{counter-increment:s;position:relative;padding:4px 0 14px 46px}
.steps li::before{content:counter(s);position:absolute;left:0;top:2px;width:32px;height:32px;border-radius:50%;background:var(--brand);color:#fff;display:grid;place-items:center;font-weight:700;font-size:.9rem}
.two{display:grid;grid-template-columns:1fr 1fr;gap:28px}
@media (max-width:760px){.two{grid-template-columns:1fr}}
/* lead */
.lead{background:#10323c;color:#e8f3f4;padding:48px 0}
.lead h2{color:#fff;margin-top:0}
.lead .muted{color:#a8c4c8}
.lead-grid{display:grid;grid-template-columns:1fr 1fr;gap:32px;align-items:start}
@media (max-width:820px){.lead-grid{grid-template-columns:1fr}}
.lead-form{background:#fff;color:var(--ink);border-radius:var(--r);padding:20px;display:grid;grid-template-columns:1fr 1fr;gap:12px}
.lead-form label{display:flex;flex-direction:column;font-size:.85rem;font-weight:600;gap:4px}
.lead-form input,.lead-form select{font:inherit;font-weight:400;padding:10px;border:1px solid var(--line);border-radius:10px;background:#fff;width:100%}
.lead-form button,.lead-form p{grid-column:1/-1}
.lead-form .muted{color:var(--muted);margin:0}
@media (max-width:480px){.lead-form{grid-template-columns:1fr}}
/* calculator */
.calc{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px;display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px}
.calc label{display:flex;flex-direction:column;font-weight:600;font-size:.9rem;gap:4px}
.calc input,.calc select{font:inherit;padding:10px;border:1px solid var(--line);border-radius:10px}
.calc-out{margin-top:16px}
.calc-out td:last-child,.calc-out th:last-child{text-align:right;white-space:nowrap}
.calc-out tr.total td{font-weight:700;background:var(--soft)}
/* footer */
.site-foot{background:#0b2128;color:#b7cbcf;padding:36px 0 90px}
.site-foot a{color:#d6e6e9}
.foot-grid{display:grid;grid-template-columns:1.2fr 1fr;gap:28px}
@media (max-width:760px){.foot-grid{grid-template-columns:1fr}}
.brand-foot{color:#fff;font-weight:700;font-size:1.1rem;margin:0 0 6px}
.foot-links{display:grid;grid-template-columns:1fr 1fr;gap:6px 18px;font-size:.9rem}
.site-foot .muted{color:#86a0a5}
.wa-float{position:fixed;right:16px;bottom:16px;width:56px;height:56px;border-radius:50%;background:var(--wa);color:#fff;display:grid;place-items:center;box-shadow:0 6px 18px rgba(0,0,0,.25);z-index:30}