:root{--bg:#F6F8F8;--paper:#FFF;--soft:#EAF0F2;--ink:#193946;--body:#374D58;--muted:#647981;--line:#D9E3E6;--dark:#122E3B;--deep:#1A4050;--teal:#168E96;--link:#226D9D;--max:1220px}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--bg);color:var(--body);font:16.5px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif;overflow-wrap:break-word}a{color:var(--link);text-underline-offset:4px}a:hover{color:#0d727a}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--teal);outline-offset:3px}h1,h2,h3{color:var(--ink);line-height:1.35;letter-spacing:.012em}h1{font-size:clamp(28px,3vw,42px);margin:0 0 20px}h2{font-size:clamp(21px,2.2vw,28px);margin:0 0 17px}h3{font-size:19px;margin:22px 0 8px}p{margin:0 0 17px}ul,ol{padding-left:1.4em}li{padding:3px 0}section[id],article[id]{scroll-margin-top:100px}.shell,.page-wrap{width:min(calc(100% - 56px),var(--max));margin-inline:auto}.site-header{position:sticky;top:0;background:var(--dark);color:white;z-index:30;border-bottom:1px solid #345160}.header-inner{width:min(calc(100% - 56px),var(--max));margin:auto;display:flex;align-items:center;gap:16px;min-height:76px}.brand{display:flex;align-items:center;flex:0 0 auto;gap:8px;color:white;text-decoration:none;white-space:nowrap}.brand-en{font-size:10px;letter-spacing:.1em;color:#c1d8df}.brand-name{font-size:20px}.brand .image-holder{padding:0;background:transparent;margin:0}.image-holder--logo img{max-height:38px;max-width:155px}.nav-desktop{display:flex;justify-content:center;align-items:stretch;gap:clamp(7px,1.1vw,17px);flex:1;min-width:0}.nav-desktop a{color:#e5eff0;text-decoration:none;font-size:clamp(12px,.9vw,14px);white-space:nowrap;padding:24px 0 22px;border-bottom:3px solid transparent}.nav-desktop a:hover,.nav-desktop a[aria-current=page]{color:white;border-bottom-color:#6bd1cb;font-weight:700}.register-link{display:inline-flex;align-items:center;justify-content:center;white-space:nowrap;padding:8px 13px;border:1px solid #9fc6c9;border-radius:7px;color:white;text-decoration:none;font-size:13px}.register-link:hover{color:white;background:var(--deep)}.menu-trigger,.nav-mobile{display:none}.skip{position:absolute;top:-80px;left:10px;z-index:60;background:white;padding:10px}.skip:focus{top:10px}.breadcrumbs{display:flex;gap:13px;padding-block:18px;font-size:14px;color:var(--muted)}.site-main{min-height:60vh}.page-wrap{padding-bottom:80px}.lead{font-size:18px;line-height:1.85;color:#48616b;max-width:800px}.eyebrow{color:var(--teal);font-size:12px;font-weight:700;letter-spacing:.11em;text-transform:uppercase;margin-bottom:11px}.page-intro{padding:38px 0 32px;border-bottom:1px solid var(--line);margin-bottom:34px}.page-intro .lead{margin-bottom:0}.section{padding:51px 0;border-bottom:1px solid var(--line)}.section:last-of-type{border-bottom:0}.narrow{max-width:780px}.reading{max-width:780px}.reading p{max-width:74ch}.muted{color:var(--muted)}.split{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(0,1fr);gap:clamp(22px,4vw,52px);align-items:center}.split--even{grid-template-columns:repeat(2,minmax(0,1fr))}.split--reverse> :first-child{order:2}.three-col{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:25px}.two-col{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:30px}.intro-hero{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(0,1fr);gap:34px;align-items:center;padding:44px 0 38px}.intro-hero p{max-width:700px}.button-link{display:inline-block;text-decoration:none;border-bottom:2px solid var(--teal);margin:5px 20px 4px 0;font-weight:700}.image-holder{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;margin:0;padding:8px;background:var(--soft);border-radius:12px}.image-holder img{display:block;width:auto;height:auto;max-width:100%;max-height:var(--image-limit,210px);object-fit:contain;object-position:center}.image-holder--hero{--image-limit:290px}.image-holder--feature{--image-limit:240px}.image-holder--inline{--image-limit:180px}.image-holder--rules{--image-limit:210px}.image-holder--banner{--image-limit:190px}.image-holder--portrait{--image-limit:330px;max-width:310px;margin-inline:auto}.image-note{font-size:13px;color:#546c74;border:1px dashed var(--line);background:var(--soft);border-radius:8px;padding:10px 13px;margin:12px 0}.topic-rows{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:0}.topic-pair{padding:8px 22px 10px;border-left:1px solid var(--line)}.topic-pair:first-child{padding-left:0;border-left:0}.topic-pair article+article{margin-top:25px;border-top:1px solid var(--line);padding-top:22px}.kicker{color:var(--teal);font-weight:700;font-size:12px}.topic-pair h3{margin:5px 0 8px;font-size:19px}.topic-pair p{font-size:15px}.soft-section{background:var(--soft);border-radius:12px;padding:28px}.deep-band{background:var(--deep);color:#e9f2f3;border-radius:12px;padding:29px}.deep-band h2,.deep-band h3{color:white}.deep-band a{color:#abebed}.quote{border-left:4px solid var(--teal);padding:14px 21px;background:var(--soft);font-size:17px;margin:24px 0}.step-line{counter-reset:step;list-style:none;padding:0}.step-line li{counter-increment:step;position:relative;padding:0 0 25px 52px;border-left:1px solid var(--line);margin-left:17px}.step-line li:before{content:counter(step,decimal-leading-zero);position:absolute;left:-17px;top:0;background:var(--dark);color:white;border-radius:50%;width:34px;height:34px;text-align:center;line-height:34px;font-size:12px}.step-line li:last-child{border:0}.step-line strong{display:block;color:var(--ink)}.section-index{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0 27px}.section-index a{background:var(--soft);border:1px solid var(--line);border-radius:7px;text-decoration:none;padding:6px 13px;font-size:14px}.reading-layout{display:grid;grid-template-columns:205px minmax(0,1fr);gap:42px}.sticky-index{align-self:start;position:sticky;top:110px;border-left:2px solid var(--line);padding:8px 0 8px 17px}.sticky-index a{display:block;margin:5px 0 17px;text-decoration:none}.reading-layout .reading{max-width:100%}.table-wrap{width:100%;overflow-x:auto;border:1px solid var(--line);border-radius:9px;margin:19px 0 24px}table{border-collapse:collapse;width:100%;min-width:560px;background:white}caption{text-align:left;font-weight:700;padding:12px 15px;color:var(--ink)}th,td{text-align:left;vertical-align:top;padding:12px 15px;border-bottom:1px solid var(--line)}th{background:var(--soft);color:var(--ink)}tr:last-child td{border-bottom:0}.mini-note{font-size:14px;color:var(--muted)}.comparison{border-top:3px solid var(--teal);padding-top:15px}.faq details{padding:16px 0;border-bottom:1px solid var(--line)}.faq summary{cursor:pointer;font-weight:700;color:var(--ink)}.faq details p{margin:10px 0 0}.related{border-top:1px solid var(--line);margin-top:55px;padding-top:25px}.related h2{font-size:22px}.related-links{display:flex;flex-wrap:wrap;gap:12px}.related-link{padding:8px 16px;background:var(--soft);border-radius:8px;text-decoration:none}.glossary{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.glossary div{border-bottom:1px solid var(--line);padding-bottom:10px}.glossary dt{font-weight:700;color:var(--ink)}.glossary dd{margin:2px 0 0}.site-footer{background:#0C2632;color:#c4d4d9}.footer-grid{display:grid;grid-template-columns:1.25fr 1fr;gap:60px;padding-block:42px}.footer-title{font-size:22px;color:white;text-decoration:none;font-weight:700}.footer-title small{font-size:11px;margin-left:9px;font-weight:400;letter-spacing:.09em}.footer-grid p{font-size:14px;max-width:590px}.footer-grid h2{color:white;font-size:17px}.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:5px 16px}.footer-links a,.footer-bottom a{color:#c8e4e8;font-size:14px}.footer-bottom{border-top:1px solid #39505a;padding-block:17px;display:flex;justify-content:space-between;gap:18px;flex-wrap:wrap;font-size:13px}@media(max-width:1100px){.header-inner{gap:10px}.brand-en{display:none}.nav-desktop{gap:9px}.nav-desktop a{font-size:12px}.register-link{padding:7px 9px}}@media(max-width:980px){.header-inner{min-height:64px;justify-content:space-between}.nav-desktop{display:none}.menu-trigger{display:flex!important;flex-direction:column;justify-content:center;gap:5px;align-items:center;width:42px;height:42px;padding:8px;border:1px solid #7896a0;border-radius:7px;background:transparent;cursor:pointer}.menu-trigger span{display:block;width:21px;height:2px;background:white}.brand{margin-inline:auto}.brand-en{display:inline;font-size:9px}.image-holder--logo img{max-height:30px}.nav-mobile{display:block;background:#193b49;border-top:1px solid #48626c}.mobile-nav-inner{width:min(calc(100% - 44px),var(--max));margin:auto;padding:10px 0 18px}.nav-mobile details{border-bottom:1px solid #54707a;padding:5px 0}.nav-mobile summary{color:#d5eff0;font-weight:700;cursor:pointer;padding:5px 0}.nav-mobile details div{display:flex;flex-wrap:wrap;gap:7px 20px;padding:6px 0 12px}.nav-mobile a{color:white;text-decoration:none;padding:5px 0}.menu-close{color:white;background:transparent;border:1px solid #7b9ca3;border-radius:7px;padding:6px 13px;margin-top:12px}.js-nav .nav-mobile{display:none}.js-nav .nav-mobile.is-open{display:block}.shell,.page-wrap,.header-inner{width:min(calc(100% - 44px),var(--max))}}@media(max-width:760px){.intro-hero,.split,.split--even,.two-col,.three-col,.reading-layout,.footer-grid{grid-template-columns:minmax(0,1fr)}.split--reverse> :first-child{order:initial}.topic-rows{grid-template-columns:1fr}.topic-pair{padding:20px 0;border-left:0;border-top:1px solid var(--line)}.topic-pair:first-child{border-top:0}.topic-pair article+article{margin-top:16px;padding-top:16px}.reading-layout{gap:12px}.sticky-index{position:static;display:flex;flex-wrap:wrap;gap:8px;border-left:0;padding:0}.sticky-index a{padding:3px 11px;border:1px solid var(--line);border-radius:6px;margin:0}.footer-grid{gap:12px}.section{padding:34px 0}.intro-hero{padding:26px 0}.page-intro{padding:20px 0 24px}.glossary{grid-template-columns:1fr}}@media(max-width:640px){body{font-size:15.5px}.shell,.page-wrap,.header-inner{width:calc(100% - 32px)}.header-inner{gap:8px}.brand-en{font-size:8px}.register-link{font-size:12px;padding:5px 8px}.intro-hero{gap:18px}.image-holder--hero{--image-limit:195px}.image-holder--feature{--image-limit:180px}.image-holder--inline{--image-limit:140px}.image-holder--rules{--image-limit:165px}.image-holder--banner{--image-limit:125px}.image-holder--portrait{--image-limit:275px;max-width:240px}.soft-section,.deep-band{padding:19px}.lead{font-size:16px}.section-index{gap:6px}.section-index a{padding:4px 9px}.step-line li{padding-bottom:19px}.footer-links{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}
