:root{--bg:#f5f7f7;--surface:#fff;--ink:#102131;--muted:#667784;--line:#dce4e8;--navy:#112735;--green:#0b8662;--green-dark:#07684d;--soft:#eef7f4;--blue:#2167d9}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:var(--bg);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Inter,Arial,sans-serif;font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased}html[lang="zh-CN"] body{font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Noto Sans CJK SC","Segoe UI",sans-serif}a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}.geo-header{position:sticky;top:0;z-index:20;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:28px;min-height:68px;padding:0 clamp(18px,4vw,64px);border-bottom:1px solid var(--line);background:rgba(255,255,255,.96);backdrop-filter:blur(12px)}.geo-brand{justify-self:start;display:flex;align-items:center;gap:10px;color:var(--ink)}.geo-brand:hover{text-decoration:none}.geo-brand span{width:34px;height:34px;display:grid;place-items:center;border-radius:8px;background:#76dfc2;color:var(--navy);font-weight:900}.geo-brand strong{font-size:18px;letter-spacing:-.02em}.geo-header nav{display:flex;gap:24px}.geo-header nav a{color:#536470;font-size:13px;font-weight:650}.lang-switch{justify-self:end;border:1px solid var(--line);border-radius:999px;padding:7px 12px;color:var(--ink);font-size:12px}.lang-switch:hover{background:#fff;text-decoration:none}.geo-main{width:min(92vw,1500px);margin:0 auto;padding:38px 0 72px}.breadcrumbs{display:flex;gap:8px;margin-bottom:18px;color:var(--muted);font-size:12px}.breadcrumbs a{color:var(--muted)}.geo-hero{display:grid;grid-template-columns:minmax(0,1fr) minmax(330px,.48fr);gap:56px;align-items:end;padding:30px 0 38px;border-bottom:1px solid var(--line)}.geo-hero.simple{align-items:start}.kicker,.section-title>p{margin:0 0 10px;color:var(--green);font-size:10px;font-weight:850;letter-spacing:.16em;text-transform:uppercase}.geo-hero h1{max-width:940px;margin:0;font-size:clamp(34px,4.2vw,60px);line-height:1.06;letter-spacing:-.045em}.lead{max-width:850px;margin:18px 0 0;color:var(--muted);font-size:clamp(15px,1.1vw,18px)}.hero-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:24px}.hero-actions a{display:inline-flex;align-items:center;min-height:42px;padding:9px 14px;border:1px solid var(--line);border-radius:6px;background:#fff;color:var(--ink);font-size:13px;font-weight:700}.hero-actions a.primary{border-color:var(--green-dark);background:var(--green-dark);color:#fff}.hero-actions a:hover{text-decoration:none}.facts{margin:0;border-top:1px solid #bdc8cd}.facts div{display:grid;grid-template-columns:126px 1fr;gap:16px;padding:11px 0;border-bottom:1px solid var(--line)}.facts dt{color:var(--muted);font-size:12px}.facts dd{margin:0;text-align:right;font-size:13px;font-weight:750}.facts code,.data-section code,.answer-block code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.92em}.answer-block,.data-section,.scope-section{padding:44px 0;border-bottom:1px solid var(--line)}.section-title{display:grid;grid-template-columns:minmax(0,.34fr) minmax(0,1fr);gap:28px;align-items:start;margin-bottom:22px}.section-title h2{margin:0;font-size:clamp(22px,2.2vw,34px);line-height:1.16;letter-spacing:-.03em}.claim-list{list-style:none;margin:0;padding:0;border-top:1px solid #becad0}.claim-list li{display:grid;grid-template-columns:minmax(0,1fr) auto auto;gap:22px;align-items:center;padding:17px 0;border-bottom:1px solid var(--line)}.claim-list strong{font-size:15px}.claim-list span{color:var(--muted);font-size:11px}.claim-list a{font-size:12px;font-weight:700}.scope-note{max-width:1000px;margin:22px 0 0;padding:14px 16px;border-left:3px solid #8ba69b;background:#f9fbfa;color:#596b64;font-size:13px}.table-wrap{overflow-x:auto;border:1px solid var(--line);background:#fff}table{width:100%;border-collapse:collapse;font-size:13px}th,td{padding:13px 14px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}tr:last-child td{border-bottom:0}th{background:#f8fafb;color:var(--muted);font-size:10px;letter-spacing:.05em;text-transform:uppercase}td small{display:block;margin-top:4px;color:var(--muted)}.source-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.source-card{display:flex;justify-content:space-between;gap:24px;align-items:center;padding:17px;border:1px solid var(--line);background:#fff}.source-card span,.source-card strong{display:block}.source-card span{color:var(--muted);font-size:10px}.source-card strong{margin-top:3px;font-size:13px}.source-card a{white-space:nowrap;font-size:11px;font-weight:750}.scope-section h2{margin:0 0 12px;font-size:22px}.scope-section p{max-width:960px;color:var(--muted)}.related{display:flex;flex-wrap:wrap;gap:10px 18px;align-items:center;padding:26px 0}.related span{color:var(--muted);font-size:10px;font-weight:800;letter-spacing:.08em;text-transform:uppercase}.related a{font-size:12px;font-weight:700}.compare-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.compare-card{padding:20px;border:1px solid var(--line);background:#fff}.compare-head{display:flex;justify-content:space-between;align-items:center;gap:14px}.compare-head h2{margin:0;font-size:19px}.compare-head a{font-size:11px;font-weight:750}.compare-card ul{margin:15px 0;padding-left:18px}.compare-card li{margin:7px 0}.compare-card>small{color:var(--muted);font-size:10px}.method-steps{list-style:none;margin:0;padding:0;border-top:1px solid #bcc8ce}.method-steps li{display:grid;grid-template-columns:54px 1fr;gap:18px;padding:18px 0;border-bottom:1px solid var(--line)}.method-steps>li>span{color:var(--green);font:800 12px ui-monospace,SFMono-Regular,Menlo,monospace}.method-steps strong{font-size:15px}.method-steps p{max-width:900px;margin:4px 0 0;color:var(--muted)}.principle-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.principle-grid article{padding:20px;border:1px solid var(--line);background:#fff}.principle-grid strong{font-size:15px}.principle-grid p{margin:7px 0 0;color:var(--muted)}.geo-footer{width:min(92vw,1500px);margin:0 auto;display:flex;justify-content:space-between;gap:24px;padding:22px 0 32px;border-top:1px solid var(--line);color:var(--muted);font-size:10px}@media(max-width:900px){.geo-header{grid-template-columns:auto 1fr auto}.geo-header nav{display:none}.geo-main{padding-top:24px}.geo-hero{grid-template-columns:1fr;gap:28px}.facts dd{text-align:left}.claim-list li{grid-template-columns:1fr;gap:5px}.source-grid,.compare-grid,.principle-grid{grid-template-columns:1fr}.section-title{grid-template-columns:1fr;gap:4px}}@media(max-width:600px){.geo-main,.geo-footer{width:min(94vw,1500px)}.geo-hero h1{font-size:34px}.source-card{align-items:flex-start;flex-direction:column;gap:8px}.geo-footer{flex-direction:column}.facts div{grid-template-columns:105px 1fr}.hero-actions a{width:100%;justify-content:center}}