:root{--paper:#f6f8f8;--white:#fff;--light:#eaf0f2;--navy:#122e3b;--panel:#1a4050;--teal:#168e96;--link:#226d9d;--heading:#193946;--text:#374d58;--muted:#647981;--line:#d9e3e6;--footer:#0c2632}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--paper);font-family:Arial,'PingFang SC','Microsoft YaHei',sans-serif;color:var(--text);font-size:16px;line-height:1.82}a{color:var(--link);text-underline-offset:3px}a:hover{text-decoration-color:var(--teal)}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #35bdc4;outline-offset:4px}img{max-width:100%}h1,h2,h3{color:var(--heading);line-height:1.35}h1{font-size:clamp(2.1rem,3.1vw,2.63rem);letter-spacing:-.025em;margin:0 0 22px}h2{font-size:clamp(1.45rem,2.15vw,1.75rem);margin:0 0 20px}h3{font-size:1.14rem;margin:24px 0 9px}p{margin:0 0 18px}ul,ol{padding-left:1.45em;margin:0 0 20px}li+li{margin-top:8px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}.skip-link{position:absolute;top:-100px;z-index:40;background:#fff;padding:8px 16px}.skip-link:focus{top:5px}.site-header{background:var(--navy);color:white;position:relative;z-index:5}.head-inner{max-width:1220px;margin:auto;min-height:76px;display:flex;align-items:center;gap:24px;padding:0 28px}.brand{display:flex;align-items:center;gap:9px;color:white;text-decoration:none;flex-shrink:0}.brand-name{font-size:21px;font-weight:bold;letter-spacing:.03em}.brand-en{font-size:10px;letter-spacing:1.6px;line-height:1.35;white-space:nowrap;max-width:75px}.brand .image-holder{padding:0;border-radius:0;background:none;margin:0}.brand img{max-height:38px;max-width:125px}.desktop-nav{display:flex;align-items:center;justify-content:center;flex:1;gap:clamp(9px,1.5vw,20px);min-width:0}.desktop-nav a{white-space:nowrap;color:#d9e8ed;text-decoration:none;font-size:13px;font-weight:500;border-bottom:3px solid transparent;padding:26px 0 21px}.desktop-nav a:hover,.desktop-nav a[aria-current=page]{color:#fff;border-bottom-color:#53c4c9}.desktop-nav a[aria-current=page]{font-weight:700}.register{white-space:nowrap;flex-shrink:0;background:var(--teal);color:white;padding:7px 13px;border-radius:7px;font-size:13px;text-decoration:none;font-weight:700}.register:hover{background:#087781}.mobile-menu,.menu-button{display:none}.breadcrumb-wrap{background:white;border-bottom:1px solid var(--line)}.breadcrumb{max-width:1220px;margin:auto;padding:9px 28px;display:flex;gap:12px;align-items:center;color:var(--muted);font-size:13px}.breadcrumb a{color:var(--muted)}main{max-width:1220px;margin:auto;padding:36px 28px 75px;min-width:0}.lead{font-size:17px;color:#526c75;max-width:800px}.eyebrow{display:block;font-size:12px;text-transform:uppercase;letter-spacing:2.5px;color:var(--teal);font-weight:700;margin-bottom:12px}.section{margin-top:56px}.section-rule{border-top:1px solid var(--line);padding-top:38px}.paper{background:white;border:1px solid var(--line);padding:clamp(20px,3vw,32px);border-radius:10px}.tinted{background:var(--light);padding:28px;border-radius:10px}.dark-panel{background:var(--panel);padding:30px;border-radius:10px;color:#e7f3f6}.dark-panel h2,.dark-panel h3{color:white}.dark-panel a{color:#a1e7ed}.hero-grid{display:grid;grid-template-columns:minmax(0,58fr) minmax(0,42fr);gap:30px;align-items:center}.hero-grid>*{min-width:0}.hero-grid h1{max-width:660px}.lead-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:22px}.text-link{display:inline-block;border-bottom:2px solid var(--teal);font-weight:bold;text-decoration:none;padding-bottom:2px}.image-holder{display:flex;align-items:center;justify-content:center;min-width:0;width:100%;padding:8px;margin:0;background:var(--light);border-radius:12px}.image-holder img{display:block;width:auto;height:auto;max-width:100%;max-height:var(--image-limit,180px);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-missing{padding:12px 15px;border-left:3px solid #9bb7c2;background:#f1f5f6;border-radius:4px;font-size:13px;color:var(--muted)}.brand .image-missing{display:none}.route-rows{display:grid;gap:0;border-top:1px solid var(--line)}.route-row{display:grid;grid-template-columns:1fr 1fr;gap:24px;border-bottom:1px solid var(--line);padding:20px 0}.route-item{display:flex;gap:16px;min-width:0}.route-no{font-size:23px;font-weight:700;color:var(--teal);line-height:1.35}.route-item h3{margin:0 0 6px}.route-item p{margin-bottom:8px;font-size:14px}.wide-narrow{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:28px}.split{display:grid;grid-template-columns:1fr 1fr;gap:34px;align-items:center}.split>*{min-width:0}.split.reversed .image-holder{order:-1}.article{max-width:780px;margin-left:auto;margin-right:auto}.article p{margin-bottom:19px}.article-section{margin-top:44px}.anchor-index{display:flex;flex-wrap:wrap;gap:9px;margin:18px 0 30px}.anchor-index a{border:1px solid var(--line);border-radius:20px;padding:5px 14px;text-decoration:none;background:white;font-size:14px}.anchor-index a:hover{border-color:var(--teal)}.side-article{display:grid;grid-template-columns:210px minmax(0,1fr);gap:34px}.chapter-nav{align-self:start;position:sticky;top:20px;border-left:2px solid var(--line);padding-left:16px}.chapter-nav a{display:block;margin:12px 0;font-size:14px}.steps{list-style:none;padding:0;counter-reset:stage}.steps li{counter-increment:stage;position:relative;border-left:2px solid #a7cbd0;padding:0 0 25px 28px;margin:0}.steps li:before{content:counter(stage);position:absolute;left:-14px;top:0;background:var(--teal);color:white;border-radius:50%;width:25px;height:25px;display:grid;place-items:center;font-size:13px;font-weight:bold}.steps h3{margin-top:0}.comparison,.table-scroll{width:100%;overflow-x:auto}.comparison table,.table-scroll table{border-collapse:collapse;width:100%;min-width:600px;background:white}.comparison th,.comparison td,.table-scroll th,.table-scroll td{padding:13px 15px;border:1px solid var(--line);text-align:left;vertical-align:top;line-height:1.65}.comparison th,.table-scroll th{background:var(--light);color:var(--heading)}caption{text-align:left;font-weight:700;padding:12px 0}.quote{border-left:4px solid var(--teal);padding:14px 20px;background:#eef5f5;font-size:17px}.concept-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.concept-grid>div{border-top:3px solid var(--teal);padding:16px 18px;background:white}.concept-grid h3{margin:0 0 9px}.band{padding:26px 0;border-bottom:1px solid var(--line)}.band:nth-child(even){background:var(--light);padding:26px}.qa details{padding:17px 0;border-bottom:1px solid var(--line)}.qa summary{cursor:pointer;font-weight:700;color:var(--heading)}.qa details p{padding:10px 18px 0 0;margin-bottom:0}.related{margin-top:60px;padding:26px 0;border-top:2px solid var(--heading)}.related-list{display:flex;flex-wrap:wrap;gap:12px}.related-list a{padding:9px 14px;border:1px solid var(--line);background:white;border-radius:7px;text-decoration:none}.related-list a:hover{border-color:var(--teal)}.footer-inner{max-width:1220px;margin:auto;padding:42px 28px 26px;display:grid;grid-template-columns:1fr 1fr;gap:30px}.site-footer{background:var(--footer);color:#c5d9e2}.site-footer strong{font-size:19px;color:white}.site-footer small{font-size:10px;letter-spacing:1px}.site-footer p{max-width:490px;font-size:14px;margin-top:12px}.site-footer nav{display:flex;flex-wrap:wrap;align-content:start;gap:10px 19px}.site-footer a{color:#c5e6ee;font-size:14px}.footer-note{grid-column:1/-1;border-top:1px solid #34515b;padding-top:18px;color:#91abb7;font-size:13px}.tag{display:inline-block;padding:2px 10px;background:#e0eff0;color:#176c75;border-radius:20px;font-size:13px}.small{font-size:14px;color:var(--muted)}@media(max-width:1100px){.head-inner{gap:13px}.desktop-nav{gap:9px}.desktop-nav a{font-size:12px}.brand-en{display:none}}@media(max-width:980px){.head-inner{height:64px;min-height:64px;justify-content:space-between;padding:0 22px}.desktop-nav{display:none}.menu-button{display:inline-grid;place-items:center;border:1px solid #53717f;border-radius:7px;background:none;color:white;font-size:25px;width:42px;height:42px;cursor:pointer}.brand{margin-right:auto;margin-left:12px}.brand-en{display:inline}.brand img{max-height:30px}.mobile-menu{display:block;color:white}.mobile-menu:not([open]) .mobile-menu-content{display:none}.mobile-summary{padding:8px 22px;font-size:13px;cursor:pointer;color:#d1e0e8;list-style:none;background:#1a4050}.mobile-summary::-webkit-details-marker{display:none}.mobile-summary:before{content:'▸ ';color:#78d6da}.mobile-menu[open] .mobile-summary:before{content:'▾ '}.mobile-menu-content{padding:18px 22px 22px;background:#1a4050;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.mobile-menu h2{color:#a9d6dd;font-size:14px;margin:0 0 7px}.mobile-menu a{display:block;color:white;padding:8px 0;font-size:15px;text-decoration:none}.breadcrumb{padding:9px 22px}main{padding:30px 22px 60px}}@media(max-width:760px){.hero-grid,.wide-narrow,.split,.side-article{grid-template-columns:1fr}.side-article{gap:10px}.chapter-nav{position:static;border-left:0;border-bottom:1px solid var(--line);display:flex;flex-wrap:wrap;gap:12px;padding:4px 0 12px}.chapter-nav a{margin:0}.split.reversed .image-holder{order:0}.concept-grid{grid-template-columns:1fr}.footer-inner{grid-template-columns:1fr}.section{margin-top:38px}}@media(max-width:640px){body{font-size:15px;line-height:1.77}h1{font-size:28px}h2{font-size:22px}.head-inner{padding:0 16px}.brand-en{display:none}.breadcrumb{padding:9px 16px}main{padding:25px 16px 44px}.route-row{grid-template-columns:1fr;gap:16px}.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}.mobile-menu-content{grid-template-columns:1fr;gap:15px;padding:12px 16px}.mobile-menu-content>div{border-bottom:1px solid #42616f;padding-bottom:10px}.paper,.tinted,.dark-panel{padding:19px}.footer-inner{padding:30px 16px}.lead{font-size:16px}.section-rule{padding-top:25px}.register{font-size:12px;padding:7px 9px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{animation-duration:.01ms!important;transition-duration:.01ms!important}}