:root{--bg:#F6F8F8;--paper:#fff;--pale:#EAF0F2;--nav:#122E3B;--deep:#1A4050;--accent:#168E96;--link:#226D9D;--head:#193946;--body:#374D58;--muted:#647981;--line:#D9E3E6;--footer:#0C2632}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:92px}body{margin:0;background:var(--bg);color:var(--body);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif}a{color:var(--link);text-underline-offset:4px}a:hover{color:var(--accent)}:focus-visible{outline:3px solid #16a0a9;outline-offset:3px}h1,h2,h3{color:var(--head);line-height:1.28;letter-spacing:.01em}h1{font-size:clamp(34px,3.1vw,42px);margin:0 0 20px}h2{font-size:clamp(24px,2.3vw,28px);margin:0 0 22px}h3{font-size:20px;margin:0 0 12px}p{margin:0 0 18px}section{margin:0 0 58px}main{min-height:55vh;padding-bottom:56px}.wrap{max-width:1220px;margin-inline:auto;padding-inline:28px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.skip{position:absolute;left:12px;top:-70px;z-index:60;background:white;padding:8px}.skip:focus{top:8px}.site-header{background:var(--nav);color:white}.header-inner{height:76px;max-width:1220px;margin:auto;padding:0 28px;display:flex;align-items:center;gap:20px;min-width:0}.brand{display:flex;align-items:center;gap:9px;color:#fff;text-decoration:none;flex-shrink:0}.brand img{display:block;max-width:160px;max-height:38px;width:auto;height:auto;object-fit:contain}.brand-name{font-size:19px;font-weight:700}.brand small{font-size:10px;letter-spacing:.11em;white-space:nowrap;color:#b7d8db}.desktop-nav{display:flex;align-items:center;justify-content:center;gap:clamp(8px,1.15vw,18px);flex:1;min-width:0}.desktop-nav a{color:#ebf2f4;text-decoration:none;white-space:nowrap;font-size:clamp(12px,1.02vw,14px);padding:24px 0 20px;border-bottom:3px solid transparent}.desktop-nav a:hover,.desktop-nav a.active{border-color:#48b5bc;font-weight:700;color:white}.entry-link{display:inline-flex;justify-content:center;align-items:center;border:1px solid #71aeb3;padding:5px 12px;border-radius:8px;color:white;white-space:nowrap;text-decoration:none;font-size:13px}.entry-link:hover{background:#235462;color:white}.mobile-menu{display:none}.breadcrumb{display:flex;gap:10px;align-items:center;font-size:13px;color:var(--muted);padding-block:17px 26px}.breadcrumb a{text-decoration:none}.eyebrow{text-transform:uppercase;font-size:12px;color:var(--accent);letter-spacing:.1em;font-weight:700;margin-bottom:12px}.lead{font-size:18px;line-height:1.85;max-width:780px}.page-intro{max-width:780px;margin:0 0 44px}.section-kicker{color:var(--accent);font-size:12px;font-weight:700;letter-spacing:.1em}.light-panel{background:var(--pale);padding:24px;border-radius:12px}.dark-panel{background:var(--deep);color:#e8f2f3;padding:28px;border-radius:12px}.dark-panel h2,.dark-panel h3{color:white}.split{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(0,1fr);gap:36px;align-items:center}.split>*{min-width:0}.split.reverse{grid-template-columns:minmax(0,1fr) minmax(0,1.3fr)}.split.wide{grid-template-columns:minmax(0,2fr) minmax(0,1fr);align-items:start}.narrow-copy{max-width:780px}.article{max-width:780px}.article p,.article li{line-height:1.83}.article h2{margin-top:42px}.article h3{margin-top:28px}.article ul,.article ol{padding-left:1.4em}.index-line{display:grid;grid-template-columns:45px minmax(0,1fr);gap:16px;border-top:1px solid var(--line);padding:23px 0}.index-line .number{color:var(--accent);font-weight:700;font-size:20px}.index-line h3{margin:0 0 5px}.index-line p{margin:0 0 5px}.route-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px}.route-group{border-top:3px solid var(--accent)}.muted{color:var(--muted)}.hero{grid-template-columns:minmax(0,1.4fr) minmax(0,1fr);padding:16px 0 0}.hero-links,.related-links{display:flex;flex-wrap:wrap;gap:10px 20px}.hero-links a{font-weight:700}.image-holder{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;margin:0;padding:8px;background:var(--pale);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-missing{background:var(--pale);border-radius:10px;padding:10px 14px;color:var(--muted);font-size:13px;max-width:420px}.two-note{border-left:3px solid var(--accent);padding:4px 0 4px 20px;margin-bottom:25px}.reading-steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;counter-reset:step}.reading-steps>div{border-top:1px solid var(--line);padding-top:14px}.reading-steps>div:before{counter-increment:step;content:'0' counter(step);display:block;color:var(--accent);font-weight:700;margin-bottom:8px}.reading-steps h3{font-size:17px}.topic-index{display:flex;flex-wrap:wrap;gap:10px;margin:12px 0 32px}.topic-index a{padding:5px 12px;border:1px solid var(--line);border-radius:7px;background:white;text-decoration:none}.with-sidebar{display:grid;grid-template-columns:200px minmax(0,1fr);gap:42px;align-items:start}.with-sidebar>*{min-width:0}.side-index{position:sticky;top:20px;background:var(--pale);padding:20px;border-radius:10px}.side-index a{display:block;padding:7px 0}.full-width{width:100%;margin:44px 0}.table-scroll{overflow-x:auto;max-width:100%;border:1px solid var(--line);border-radius:10px;background:#fff}table{border-collapse:collapse;width:100%;min-width:620px;font-size:15px}caption{text-align:left;padding:15px 18px;font-weight:700;color:var(--head)}th,td{border-bottom:1px solid var(--line);padding:13px 16px;vertical-align:top;text-align:left}th{background:var(--pale);color:var(--head)}tr:last-child td{border-bottom:0}.three-cols{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}.concept{padding:20px 0;border-top:3px solid var(--accent)}.concept h3{margin:0 0 12px}.stripe{padding:28px;border-left:5px solid var(--accent);background:white;margin:0 0 18px}.stripe:nth-child(even){background:var(--pale)}.timeline{counter-reset:phase}.timeline>div{position:relative;margin-bottom:20px;padding:14px 20px 14px 65px;border-left:2px solid var(--line)}.timeline>div:before{counter-increment:phase;content:counter(phase);position:absolute;left:16px;top:14px;font-size:22px;font-weight:700;color:var(--accent)}.timeline h3{margin-bottom:4px}.related{border-top:2px solid var(--head);padding-top:24px;margin-top:50px}.related h2{font-size:22px}.related-links a{padding:8px 12px;background:var(--pale);border-radius:8px;text-decoration:none}.faq-list{display:grid;gap:10px}.faq-list details{border:1px solid var(--line);background:white;border-radius:9px;padding:12px 18px}.faq-list summary{font-weight:700;color:var(--head);cursor:pointer}.faq-list p{margin:10px 0 2px}.guide-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}.guide-grid>div{background:white;border-top:2px solid var(--accent);padding:22px}.site-footer{background:var(--footer);color:#bdcdd4}.footer-grid{display:grid;grid-template-columns:1fr 1fr;gap:60px;padding-block:50px 30px}.footer-grid h2{color:white;font-size:19px}.footer-brand{color:white;font-size:21px;font-weight:700;text-decoration:none}.footer-brand small{display:block;font-size:10px;letter-spacing:.12em;font-weight:400}.footer-grid p{max-width:480px}.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 15px}.footer-links a{color:#d0e5e9;text-decoration:none}.footer-bottom{border-top:1px solid #31505e;padding-block:20px 27px;font-size:13px}.pullquote{border-left:4px solid var(--accent);padding:14px 22px;background:var(--pale);font-size:18px;color:var(--head);margin:24px 0}.text-band{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:28px 0}.center-image{max-width:850px;margin:0 auto 32px}.service-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.service-links a{background:var(--pale);padding:14px;border-radius:8px;text-decoration:none}.info-strip{padding:20px 24px;background:var(--pale);border-left:4px solid var(--accent)}@media(max-width:1150px){.header-inner{gap:12px;padding-inline:22px}.brand small{display:none}.desktop-nav{gap:11px}}@media(max-width:980px){.desktop-nav{display:none}.header-inner{height:64px;justify-content:space-between}.brand{position:absolute;left:50%;transform:translateX(-50%);max-width:50%;justify-content:center}.brand img{max-height:30px;max-width:140px}.brand small{display:none}.mobile-menu{display:block;position:relative;z-index:22}.mobile-menu>summary{display:flex;align-items:center;justify-content:center;list-style:none;color:white;width:44px;height:44px;cursor:pointer;border:1px solid #5a8190;border-radius:8px}.mobile-menu>summary::-webkit-details-marker{display:none}.menu-icon{font-size:24px}.mobile-menu nav{position:absolute;left:-22px;top:54px;width:min(100vw,500px);max-height:calc(100vh - 70px);overflow-y:auto;box-shadow:0 12px 30px #122e3b33;background:white;color:var(--body);border-radius:0 0 12px 12px;padding:20px}.mobile-menu nav strong{display:block;color:var(--head);font-size:12px;margin:14px 0 5px}.mobile-menu nav a{display:block;padding:9px 8px;border-bottom:1px solid var(--line);text-decoration:none}.menu-close{background:var(--nav);color:white;border:0;border-radius:6px;padding:9px 18px;margin-top:15px;cursor:pointer}.entry-link{margin-left:auto}.wrap{padding-inline:22px}.route-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:760px){.split,.split.reverse,.split.wide,.with-sidebar,.footer-grid,.guide-grid{grid-template-columns:1fr}.split{gap:20px}.with-sidebar{gap:10px}.side-index{position:static}.three-cols,.service-links{grid-template-columns:1fr}.reading-steps{grid-template-columns:repeat(2,minmax(0,1fr))}.hero{padding-top:0}.footer-grid{gap:16px}.route-grid{grid-template-columns:1fr}.page-intro{margin-bottom:32px}.split.reverse .image-holder{order:2}}@media(max-width:640px){body{font-size:15px;line-height:1.75}h1{font-size:28px}h2{font-size:22px}h3{font-size:18px}.wrap{padding-inline:16px}.header-inner{padding-inline:16px}.mobile-menu nav{left:-16px}.brand img{max-width:115px}.entry-link{padding:5px 9px;font-size:12px}.lead{font-size:16px}section{margin-bottom:36px}.light-panel,.dark-panel{padding: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}.footer-links{grid-template-columns:1fr 1fr}.reading-steps{gap:14px}.breadcrumb{padding-block:12px 20px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}