:root{--bg:#F4F7FA;--surface:#fff;--pale:#EAF1F6;--mint:#E9F8F8;--nav:#102E46;--deep:#163C57;--teal:#13B8C5;--blue:#237BD3;--title:#18364B;--text:#344C60;--muted:#64798A;--border:#DCE6ED;--page:1200px}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:var(--bg);font-family:Arial,'PingFang SC','Microsoft YaHei',sans-serif;color:var(--text);font-size:16px;line-height:1.8;overflow-wrap:break-word}a{color:#176da6;text-decoration:none}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--teal);outline-offset:3px}img{max-width:100%}h1,h2,h3,p{margin-top:0}h1,h2,h3{color:var(--title);line-height:1.37}h1{font-size:36px;letter-spacing:-.025em}h2{font-size:27px;margin-bottom:20px}h3{font-size:20px;margin-bottom:12px}p{margin-bottom:17px}small,.muted{color:var(--muted)}.shell{width:min(var(--page),calc(100% - 56px));margin-inline:auto}.section{margin-top:62px;margin-bottom:62px}.section-sm{margin-top:42px;margin-bottom:42px}.eyebrow{font-size:13px;letter-spacing:.1em;font-weight:700;color:#167985;margin-bottom:8px}.section-intro{max-width:770px}.reading{max-width:790px}.reading p,.reading li{line-height:1.85}.page-intro{padding:39px 0 30px;border-bottom:1px solid var(--border)}.page-intro .lead{max-width:850px;font-size:17px}.page-intro h1{margin-bottom:15px}.crumbs{font-size:13px;color:var(--muted);display:flex;align-items:center;gap:10px;margin-bottom:18px}.crumbs a{color:var(--muted)}.skip-link{position:absolute;top:-80px;left:10px;z-index:1000;padding:10px;background:white}.skip-link:focus{top:8px}.site-header{background:#fff}.brand-bar{height:72px;display:flex;align-items:center;gap:20px}.brand{display:flex;align-items:center;flex-shrink:0;min-width:0;color:var(--nav)}.brand img{display:block;width:auto;height:auto;max-height:38px;max-width:235px;object-fit:contain}.brand-text{font-size:23px;font-weight:800;letter-spacing:.02em;white-space:nowrap;line-height:1.15}.brand-text small{display:block;font-size:10px;letter-spacing:.14em}.brand-note{font-size:13px;color:var(--muted);border-left:1px solid var(--border);padding-left:20px}.register-link{margin-left:auto;background:var(--deep);color:white;border-radius:9px;padding:7px 17px;font-weight:700;white-space:nowrap}.register-link:hover{background:#0e6074;color:white;text-decoration:none}.desktop-nav{background:var(--nav)}.nav-layout{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));align-items:stretch;min-height:50px}.nav-layout a{text-align:center;color:#e6f2f8;font-size:15px;padding:10px 3px;position:relative;white-space:nowrap}.nav-layout a:hover,.nav-layout a.is-active{color:white;background:#163C57;text-decoration:none;font-weight:700}.nav-layout a.is-active:after{content:'';position:absolute;bottom:0;left:28%;right:28%;height:3px;background:var(--teal)}.menu-toggle,.mobile-drawer,.drawer-overlay,.mobile-shortcuts,.noscript-nav{display:none}.btn,.btn-outline{display:inline-flex;align-items:center;justify-content:center;min-height:42px;border-radius:9px;padding:9px 18px;font-weight:700;background:var(--deep);color:white}.btn:hover{background:#0f617c;color:#fff;text-decoration:none}.btn-outline{border:1px solid #267589;background:transparent;color:#145c71}.btn-outline:hover{background:#dceff2;text-decoration:none}.action-row{display:flex;gap:12px;flex-wrap:wrap}.hero-home{display:grid;grid-template-columns:minmax(0,1.08fr) minmax(0,1fr);gap:38px;align-items:center;padding-top:42px;padding-bottom:12px}.hero-home h1{font-size:42px;margin-bottom:20px}.hero-home p{max-width:590px}.hero-home .action-row{margin-top:25px}.media-frame{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;margin:0;padding:9px;border:1px solid var(--border);border-radius:14px;background:var(--pale);overflow:hidden}.media-frame img{display:block;width:auto;height:auto;max-width:100%;max-height:var(--media-limit,220px);object-fit:contain;object-position:center}.media-frame--hero{--media-limit:310px}.media-frame--feature{--media-limit:250px}.media-frame--card{--media-limit:185px}.media-frame--wide{--media-limit:210px}.media-frame--mobile{--media-limit:350px;max-width:320px;margin-inline:auto}.media-placeholder{min-height:120px;max-height:210px;color:#6c8796;font-size:14px;background:repeating-linear-gradient(130deg,#EAF1F6,#EAF1F6 18px,#e3edf3 18px,#e3edf3 36px)}.media-frame--hero.media-placeholder{min-height:225px}.media-frame--mobile.media-placeholder{min-height:250px}.kicker-number{font-weight:800;color:#138b99;font-size:13px}.directory-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 44px;border-top:1px solid var(--border)}.directory-entry{border-bottom:1px solid var(--border);padding:24px 0;display:grid;grid-template-columns:36px minmax(0,1fr);gap:10px}.directory-entry h3{font-size:19px;margin:0 0 6px}.directory-entry p{font-size:15px;margin-bottom:4px}.feature-layout{display:grid;grid-template-columns:minmax(0,2fr) minmax(0,1fr);gap:24px}.feature-lead{padding:30px;background:white;border-left:4px solid var(--teal)}.feature-lead h3{font-size:24px}.feature-side{display:flex;flex-direction:column;gap:14px}.feature-side article{padding:19px;background:var(--pale)}.split{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:38px;align-items:center}.split--wide-copy{grid-template-columns:minmax(0,.75fr) minmax(0,1.25fr)}.band{padding:32px;background:var(--pale);border-radius:14px}.band-mint{background:var(--mint)}.band-dark{background:var(--deep);color:#e9f4f8}.band-dark h2,.band-dark h3{color:#fff}.band-dark a{color:#bbf7ff}.lesson-stack{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;align-items:start}.lesson-stack article{padding:24px;border-top:3px solid var(--teal);background:white}.lesson-stack article:nth-child(2){margin-top:24px}.lesson-stack article:nth-child(3){margin-top:48px}.step-track{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px;counter-reset:steps}.step-track article{padding:21px 17px;border-top:3px solid #267789;background:white;min-width:0}.step-track article:before{counter-increment:steps;content:'0' counter(steps);display:block;font-size:15px;font-weight:700;color:#158b98;margin-bottom:10px}.step-track h3{font-size:18px}.related-links{border-top:1px solid var(--border);padding-top:22px;margin:40px 0}.related-links strong{display:block;color:var(--title);margin-bottom:10px}.related-links>div{display:flex;gap:10px 24px;flex-wrap:wrap}.related-links a{font-weight:700;font-size:15px}.local-nav{display:flex;flex-wrap:wrap;gap:10px;margin:24px 0}.local-nav a{border:1px solid #bad4dd;border-radius:8px;padding:7px 13px;background:#fff;color:var(--deep);font-weight:700;font-size:14px}.local-nav a:hover{background:var(--mint);text-decoration:none}.knowledge-columns{display:grid;grid-template-columns:minmax(0,2.2fr) minmax(220px,.8fr);gap:35px}.knowledge-columns>*{min-width:0}.note-box{background:var(--mint);padding:22px;border-left:3px solid var(--teal);margin:24px 0}.fact-rail{background:white;border:1px solid var(--border);border-radius:12px;padding:23px;align-self:start}.fact-rail h3{font-size:18px}.fact-rail ul{padding-left:20px;margin:0}.fact-rail li{margin:10px 0}.table-scroll{max-width:100%;overflow-x:auto;border:1px solid var(--border);border-radius:12px;background:#fff}.data-table{border-collapse:collapse;width:100%;min-width:630px;line-height:1.65}.data-table caption{caption-side:top;text-align:left;padding:15px 18px;font-size:14px;font-weight:700;color:var(--title)}.data-table th,.data-table td{border-bottom:1px solid var(--border);padding:13px 16px;text-align:left;vertical-align:top}.data-table th{background:#eaf1f6;color:var(--title)}.data-table tr:last-child td{border-bottom:0}.flow-line{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.flow-line>div{position:relative;background:#fff;border:1px solid var(--border);border-radius:10px;padding:20px}.flow-line h3{font-size:18px}.vertical-steps{counter-reset:vs;display:grid;gap:20px}.vertical-steps article{position:relative;padding:20px 22px 20px 72px;border-left:3px solid var(--teal);background:#fff}.vertical-steps article:before{counter-increment:vs;content:counter(vs);position:absolute;left:22px;top:20px;font-size:27px;font-weight:800;color:#178c9a}.definition-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:17px}.definition-list article{border-bottom:1px solid var(--border);padding:15px 0}.definition-list h3{font-size:18px}.project-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.project-grid article{background:#fff;padding:24px;border-top:4px solid var(--teal)}.project-grid article:nth-child(2){border-top-color:var(--blue)}.project-grid article:nth-child(3){border-top-color:var(--deep)}.project-grid h3{margin-bottom:9px}.gallery-grid{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,.9fr);gap:22px;align-items:start}.gallery-grid article{padding:24px;background:#fff;border:1px solid var(--border)}.gallery-grid article:nth-child(2){margin-top:50px}.gallery-grid .media-frame{margin-bottom:18px}.rule-layout{display:grid;grid-template-columns:minmax(180px,.6fr) minmax(0,2fr);gap:38px}.rule-index{position:sticky;top:20px;align-self:start;background:#fff;border:1px solid var(--border);padding:20px;border-radius:12px}.rule-index a{display:block;padding:9px 0;border-bottom:1px solid var(--border)}.rule-index a:last-child{border:0}.rule-content>section{margin-bottom:56px}.faq-list{border-top:1px solid var(--border)}.faq-list details{border-bottom:1px solid var(--border);background:rgba(255,255,255,.62)}.faq-list summary{padding:16px 18px;cursor:pointer;color:var(--title);font-weight:700}.faq-list details p{padding:0 18px 19px;margin:0}.help-layout{display:grid;grid-template-columns:minmax(180px,.6fr) minmax(0,2fr);gap:40px}.help-side{background:#fff;padding:23px;align-self:start;border:1px solid var(--border)}.help-side a{display:block;padding:7px 0}.help-main section{margin-bottom:50px}.site-footer{background:#0B2539;color:#DCECF5;margin-top:60px;padding-top:48px}.footer-grid{display:grid;grid-template-columns:1.5fr 1fr;gap:50px}.footer-brand{font-weight:800;font-size:23px;color:#fff}.footer-brand span{display:block;font-size:11px;letter-spacing:.12em;font-weight:500}.footer-fine{font-size:14px;max-width:650px;color:#c3d8e3}.site-footer nav strong{display:block;margin-bottom:13px}.site-footer nav>div{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.site-footer nav a{color:#deeff5}.footer-bottom{border-top:1px solid #345062;margin-top:32px;padding:19px 0;display:flex;justify-content:space-between;font-size:13px;color:#bdcfdb}.back-top{display:none;position:fixed;bottom:22px;right:22px;z-index:20;width:43px;height:43px;border:1px solid #98cbd4;border-radius:50%;background:#fff;color:var(--deep);font-size:23px;cursor:pointer;box-shadow:0 3px 10px #0001}.back-top.shown{display:block}.callout-quote{border-left:4px solid var(--teal);padding:14px 26px;background:var(--mint);font-size:19px;color:var(--deep)}
@media(max-width:1200px){.shell{width:calc(100% - 44px)}.hero-home{gap:26px}.section{margin-top:51px;margin-bottom:51px}}@media(max-width:920px){.brand-bar{height:62px;justify-content:space-between;gap:8px}.menu-toggle{display:flex;flex-direction:column;justify-content:center;align-items:center;gap:5px;width:40px;height:40px;flex:none;background:transparent;border:1px solid var(--border);border-radius:8px;cursor:pointer}.menu-toggle span{display:block;width:19px;height:2px;background:var(--nav)}.brand{margin:auto}.brand img{max-height:30px;max-width:min(42vw,190px)}.brand-text{font-size:19px}.brand-text small{font-size:8px}.brand-note,.desktop-nav{display:none}.register-link{margin:0;padding:7px 10px;min-height:39px;font-size:13px}.drawer-overlay{display:block;position:fixed;inset:0;background:rgba(6,23,37,.56);z-index:49;opacity:0;visibility:hidden;pointer-events:none;transition:opacity .22s,visibility .22s}.drawer-overlay.visible{opacity:1;visibility:visible;pointer-events:auto}.mobile-drawer{display:block;position:fixed;inset:0 auto 0 0;width:min(86vw,340px);background:#fff;z-index:50;transform:translateX(-104%);visibility:hidden;transition:transform .22s,visibility .22s;overflow-y:auto;box-shadow:4px 0 22px #0002}.mobile-drawer.open{transform:translateX(0);visibility:visible}.menu-open{overflow:hidden}.drawer-head{height:66px;display:flex;align-items:center;justify-content:space-between;padding:0 22px;border-bottom:1px solid var(--border);color:var(--title)}.drawer-head button{width:40px;height:40px;cursor:pointer;border:0;background:#eaf1f6;border-radius:9px;color:var(--title);font-size:26px}.mobile-drawer nav{padding:14px 22px 34px}.mobile-drawer nav p{font-size:12px;font-weight:800;color:var(--muted);margin:16px 0 4px}.mobile-drawer nav a{display:block;padding:9px 12px;border-radius:8px;color:var(--title);font-weight:600}.mobile-drawer nav a.is-active{background:var(--mint);border-left:3px solid var(--teal)}.mobile-shortcuts{display:flex;gap:14px;flex-wrap:wrap;margin-top:25px;font-size:14px;justify-content:center}.noscript-nav{display:flex;flex-wrap:wrap;gap:8px;padding:12px 0}.noscript-nav a{padding:5px 9px;border:1px solid var(--border)}.hero-home h1{font-size:36px}}@media(max-width:760px){.hero-home,.split,.split--wide-copy,.feature-layout,.knowledge-columns,.gallery-grid,.rule-layout,.help-layout,.footer-grid{grid-template-columns:1fr}.hero-home{gap:22px}.split,.split--wide-copy{gap:20px}.feature-side{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}.fact-rail{margin-top:12px}.gallery-grid article:nth-child(2){margin-top:0}.rule-index{position:static;display:flex;flex-wrap:wrap;gap:6px 18px}.rule-index h3{width:100%;margin:0}.rule-index a{border:0}.help-main{order:1}.help-side{order:2}.step-track{grid-template-columns:repeat(2,minmax(0,1fr))}.project-grid{grid-template-columns:1fr}.footer-grid{gap:20px}.lesson-stack article:nth-child(2),.lesson-stack article:nth-child(3){margin-top:0}.lesson-stack{grid-template-columns:1fr}.flow-line{grid-template-columns:1fr}}@media(max-width:640px){body{font-size:15px}.shell{width:calc(100% - 32px)}h1{font-size:27px}h2{font-size:22px}h3{font-size:18px}.section{margin-top:37px;margin-bottom:37px}.section-sm{margin-top:30px;margin-bottom:30px}.page-intro{padding:25px 0 20px}.page-intro .lead{font-size:15px}.hero-home{padding-top:27px}.hero-home h1{font-size:29px}.directory-grid,.feature-side,.definition-list{grid-template-columns:1fr}.directory-entry{padding:17px 0}.feature-lead{padding:20px}.band{padding:20px}.step-track{gap:10px}.step-track article{padding:15px 13px}.media-frame{padding:7px}.media-frame--hero{--media-limit:205px}.media-frame--feature{--media-limit:185px}.media-frame--card{--media-limit:145px}.media-frame--wide{--media-limit:135px}.media-frame--mobile{--media-limit:285px;max-width:250px}.media-frame--hero.media-placeholder{min-height:145px}.media-placeholder{min-height:90px}.site-footer{padding-top:34px}.footer-bottom{display:block}.footer-bottom span{display:block}.brand-text{font-size:17px}.brand-text small{font-size:7px}.brand img{max-width:40vw}.register-link{padding:7px;font-size:12px}.callout-quote{font-size:17px}.vertical-steps article{padding-left:57px}.vertical-steps article:before{left:17px}}@media(max-width:370px){.brand img{max-width:36vw}.brand-text{font-size:15px}.register-link{font-size:11px;padding:6px}.menu-toggle{width:39px}.shell{width:calc(100% - 30px)}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation-duration:.01ms!important;transition-duration:.01ms!important}}