:root{--bg:#F4F7FA;--surface:#fff;--soft:#EAF1F6;--mint:#E9F8F8;--nav:#102E46;--nav2:#163C57;--teal:#13B8C5;--blue:#237BD3;--heading:#18364B;--body:#344C60;--muted:#64798A;--line:#DCE6ED;--max:1200px}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:22px}body{margin:0;background:var(--bg);color:var(--body);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif;overflow-wrap:break-word}body.drawer-open{overflow:hidden}a{color:#1164ad;text-decoration:none}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #00a3b1;outline-offset:3px}img{max-width:100%}button{font:inherit;cursor:pointer}.container{width:min(calc(100% - 56px),var(--max));margin-inline:auto}.skip-link{position:absolute;left:12px;top:-90px;background:white;z-index:200;padding:8px 18px}.skip-link:focus{top:10px}h1,h2,h3{color:var(--heading);line-height:1.35;letter-spacing:-.015em}h1{font-size:35px;margin:0 0 20px}h2{font-size:26px;margin:0 0 20px}h3{font-size:20px;margin:0 0 10px}p{margin:0 0 17px}ul,ol{padding-left:1.35em}li{margin-bottom:8px}section{scroll-margin-top:24px}section+section{margin-top:58px}.page-content{padding-top:32px;padding-bottom:75px;min-height:60vh}.lead{font-size:17px;color:#415b70;line-height:1.85}.eyebrow{display:inline-block;font-weight:800;color:#087b87;font-size:12px;letter-spacing:.14em;margin-bottom:10px;text-transform:uppercase}.section-kicker{font-size:13px;font-weight:700;letter-spacing:.08em;color:#0d7d8d}.tag{font-size:12px;border:1px solid #bdd6e0;border-radius:30px;padding:2px 10px;display:inline-block;color:#32677d}.breadcrumb{font-size:13px;display:flex;gap:12px;align-items:center;color:var(--muted);margin-bottom:27px}.breadcrumb a{color:#507188}.brand-bar{background:var(--surface)}.brand-inner{height:72px;display:flex;align-items:center;gap:26px}.brand{display:flex;align-items:center;flex:0 0 auto;max-width:230px}.brand-subtitle{font-size:13px;color:#6c7d88;white-space:nowrap}.brand-subtitle i{font-style:normal;color:#a6bdc9;margin:0 7px}.entry-link{margin-left:auto;border-radius:8px;background:var(--nav2);color:white;font-weight:700;padding:9px 22px;white-space:nowrap;font-size:14px}.entry-link:hover{color:white;background:#1b536f;text-decoration:none}.desktop-nav{background:var(--nav)}.nav-grid{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));align-items:stretch}.nav-grid a{font-size:14px;color:#dbe8f1;display:flex;justify-content:center;align-items:center;text-align:center;min-height:50px;font-weight:500;position:relative;white-space:nowrap}.nav-grid a:hover{color:white;background:#1c4059;text-decoration:none}.nav-grid a[aria-current=page]{color:white;font-weight:800}.nav-grid a[aria-current=page]:after{content:"";position:absolute;width:29px;height:3px;background:var(--teal);bottom:0;left:calc(50% - 14.5px)}.menu-toggle{display:none}.brand .media-frame,.footer-brand .media-frame{padding:0;background:none;border:0;border-radius:0;min-height:0;width:auto}.media-frame--logo img{width:auto;max-width:100%;max-height:38px;height:auto}.media-frame--logo.media-missing{width:160px;min-height:36px;background:#e3edf3}.media-frame--logo.media-missing span{font-size:11px}.media-frame{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;max-width:100%;padding:9px;border-radius:14px;background:var(--soft);border:1px solid #dce8ee;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--article{--media-limit:220px}.media-frame--card{--media-limit:185px}.media-frame--wide{--media-limit:210px}.media-frame--mobile{--media-limit:350px;max-width:320px;margin:auto}.media-missing{min-height:100px;aspect-ratio:16/7;background:linear-gradient(135deg,#eaf1f6,#f8fbfc);color:#667e90;justify-content:center}.media-missing span{font-size:13px}.media-frame--mobile.media-missing{aspect-ratio:3/4}.media-frame--hero.media-missing{aspect-ratio:16/10}.hero{display:grid;grid-template-columns:52fr 48fr;gap:35px;align-items:center;padding:30px 0 12px}.hero h1{font-size:42px;max-width:640px}.hero .lead{max-width:590px}.hero-links,.link-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:24px}.button-primary,.button-outline{display:inline-flex;align-items:center;justify-content:center;border-radius:8px;padding:10px 21px;min-height:44px;font-weight:700;font-size:14px}.button-primary{background:var(--nav2);color:white}.button-primary:hover{background:#215574;color:white;text-decoration:none}.button-outline{border:1px solid #b7cad6;background:white;color:#28566e}.button-outline:hover{border-color:#217ca6;text-decoration:none}.topic-directory{border-top:1px solid var(--line);padding-top:26px}.topic-directory .directory-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 48px}.directory-item{padding:18px 0 20px;border-bottom:1px solid var(--line)}.directory-item h3{font-size:19px;margin-bottom:7px}.directory-item p{font-size:15px;margin-bottom:10px}.directory-item a{font-weight:700;font-size:14px}.asym-grid{display:grid;grid-template-columns:2fr 1fr;gap:18px}.feature-main{background:var(--nav);color:#e8f0f5;padding:32px;border-radius:12px}.feature-main h3{font-size:26px;color:white}.feature-main p{color:#dae7ef}.feature-main a{color:#7ee2ea;font-weight:700}.side-stack{display:grid;gap:16px}.side-stack article{border:1px solid var(--line);border-radius:10px;padding:24px;background:white}.editorial-split{display:grid;grid-template-columns:46% 1fr;gap:38px;align-items:center}.editorial-split.reverse{grid-template-columns:1fr 42%}.editorial-split.reverse .media-frame{grid-column:2;grid-row:1}.editorial-split.reverse .split-copy{grid-column:1;grid-row:1}.writing-band{background:var(--mint);padding:30px 35px;border-radius:12px;border-left:4px solid var(--teal)}.rule-teasers{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:19px;align-items:start}.rule-teasers article{padding:19px 21px;border-top:3px solid #18a7b4;background:#fff;border-radius:0 0 9px 9px}.rule-teasers article:nth-child(2){margin-top:24px}.rule-teasers article:nth-child(3){margin-top:48px}.route-steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;counter-reset:route}.route-steps article{border-top:1px solid #92b7c8;padding:18px 7px 0}.route-steps article:before{counter-increment:route;content:"0" counter(route);display:block;color:#13838f;font-size:23px;font-weight:800}.route-steps h3{font-size:18px}.notice{border-left:3px solid #13b8c5;padding:14px 20px;background:#e9f8f8;color:#35586a;font-size:15px}.page-intro{max-width:900px;padding:17px 0 20px}.page-intro p{max-width:800px}.anchor-nav{display:flex;gap:10px;flex-wrap:wrap;padding:13px 0 23px;margin-bottom:20px;border-bottom:1px solid var(--line)}.anchor-nav a{border:1px solid #c3d7e2;border-radius:30px;padding:5px 15px;background:white;font-size:14px;font-weight:700}.content-with-aside{display:grid;grid-template-columns:minmax(0,1fr) 265px;gap:45px;align-items:start}.reading-column{max-width:800px;min-width:0}.reading-column section{margin-top:48px}.info-aside{background:#eaf1f6;padding:22px;border-radius:12px;font-size:14px}.info-aside ul{margin-bottom:0}.article-narrow{max-width:800px;margin-inline:auto}.article-wide{max-width:1020px;margin-inline:auto}.prose-block{max-width:780px}.soft-panel{border:1px solid var(--line);background:white;border-radius:12px;padding:25px}.chapter-number{font-size:13px;color:#0b8a97;letter-spacing:.08em;font-weight:800;margin-bottom:7px}.step-flow{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:18px 0}.step-flow article{position:relative;background:#eaf1f6;border-radius:10px;padding:19px}.step-flow article strong{display:block;color:#116e83}.step-flow p{font-size:14px;margin:4px 0 0}.comparison-table{width:100%;border-collapse:collapse;background:white;font-size:15px;min-width:620px}.comparison-table caption{font-weight:700;color:var(--heading);text-align:left;padding:0 0 12px;font-size:17px}.comparison-table th,.comparison-table td{padding:14px 16px;text-align:left;vertical-align:top;border:1px solid var(--line)}.comparison-table th{background:#eaf1f6;color:var(--heading)}.comparison-table tbody tr:nth-child(even){background:#f8fbfd}.table-scroll{overflow-x:auto;max-width:100%;border-radius:10px;margin:20px 0}.numbered-list{counter-reset:read;list-style:none;padding:0}.numbered-list li{counter-increment:read;padding:14px 0 14px 54px;border-bottom:1px solid var(--line);position:relative}.numbered-list li:before{content:counter(read,decimal-leading-zero);position:absolute;left:0;top:12px;color:#0a8397;font-weight:800;font-size:21px}.tactic-cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.tactic-cards article{border-left:3px solid var(--teal);background:white;padding:20px}.metric-matrix{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.metric-matrix article{border:1px solid var(--line);background:white;padding:22px;border-radius:12px}.metric-matrix h3{margin-top:0}.timeline{display:grid;gap:16px;max-width:810px}.timeline article{padding:22px 24px 22px 32px;background:white;border-left:4px solid var(--teal);border-radius:0 9px 9px 0}.gallery-pair{display:grid;grid-template-columns:1.07fr .93fr;gap:28px;align-items:center}.gallery-pair.offset{grid-template-columns:.9fr 1.1fr}.gallery-pair.offset .media-frame{grid-column:2;grid-row:1}.gallery-pair.offset .gallery-copy{grid-column:1;grid-row:1}.editorial-quote{border-top:2px solid #25a6b4;border-bottom:1px solid #dce6ed;padding:22px 0;font-size:20px;color:var(--heading);font-weight:600}.rule-handbook{display:grid;grid-template-columns:235px minmax(0,1fr);gap:35px;align-items:start}.rule-index{padding:20px;background:#fff;border:1px solid var(--line);border-radius:12px;position:sticky;top:15px}.rule-index a{display:block;padding:9px 0;border-bottom:1px solid var(--line);font-size:14px}.rule-index a:last-child{border:0}.rule-body{min-width:0}.rule-body section{margin-top:46px}.faq-list details{background:white;border:1px solid var(--line);border-radius:9px;margin-bottom:10px;padding:0 18px}.faq-list summary{cursor:pointer;font-weight:700;color:var(--heading);padding:14px 4px}.faq-list details p{border-top:1px solid var(--line);padding:15px 4px 17px;margin:0;font-size:15px}.service-layout{display:grid;grid-template-columns:minmax(0,1fr) 220px;gap:40px}.service-main{min-width:0}.service-menu{background:#eaf1f6;border-radius:12px;padding:21px;align-self:start;position:sticky;top:10px}.service-menu a{display:block;margin:10px 0;font-size:14px}.related-links{border-top:1px solid var(--line);margin-top:55px;padding-top:25px}.related-links h2{font-size:22px}.related-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.related-list a{padding:14px 17px;background:white;border:1px solid var(--line);border-radius:9px;font-weight:700;font-size:14px}.related-list a:hover{border-color:#2aa4b6}.site-footer{background:#0b2539;color:#dcecf5;padding:44px 0 20px;font-size:14px}.footer-layout{display:grid;grid-template-columns:1.6fr 1fr;gap:80px}.footer-layout p{max-width:690px;color:#d2e3ed}.footer-brand{display:flex;align-items:center;gap:15px;color:white;margin-bottom:10px}.footer-links{display:grid;grid-template-columns:1fr 1fr;gap:3px 12px;margin-top:10px}.site-footer a{color:#d7ecf6}.footer-bottom{border-top:1px solid #31536a;margin-top:30px;padding-top:16px;display:flex;justify-content:space-between;gap:20px;color:#bdcfdb}.mobile-quick{display:none}.back-to-top{position:fixed;bottom:20px;right:20px;z-index:15;border:0;background:#163c57;color:white;border-radius:50%;width:42px;height:42px;box-shadow:0 2px 12px #0002}.back-to-top[hidden]{display:none}.drawer-shade,.mobile-drawer{display:none}.nojs-nav{display:none}
@media(max-width:1200px){.container{width:calc(100% - 44px)}.hero h1{font-size:39px}.brand-subtitle{font-size:12px}.content-with-aside{gap:28px}}
@media(max-width:920px){.brand-inner{height:62px;display:grid;grid-template-columns:40px minmax(0,1fr) auto;gap:10px;position:relative}.menu-toggle{display:flex;width:40px;height:40px;border:1px solid #dce6ed;background:white;border-radius:8px;align-items:center;justify-content:center;flex-direction:column;gap:4px}.menu-toggle span{display:block;height:2px;width:19px;background:#18364b}.brand{justify-self:center;max-width:min(46vw,210px);min-width:0}.brand .media-frame--logo img{max-height:30px}.brand-subtitle,.desktop-nav{display:none}.entry-link{font-size:12px;padding:8px 10px;min-height:38px;display:flex;align-items:center;justify-content:center;line-height:1.2}.drawer-shade{display:block;position:fixed;inset:0;background:rgba(8,26,42,.55);z-index:100;visibility:hidden;pointer-events:none;opacity:0;transition:opacity .2s,visibility .2s}.drawer-shade.is-visible{opacity:1;visibility:visible;pointer-events:auto}.mobile-drawer{display:block;position:fixed;left:0;top:0;bottom:0;width:min(86vw,340px);overflow-y:auto;background:white;z-index:101;transform:translateX(-102%);visibility:hidden;pointer-events:none;transition:transform .23s,visibility .23s;box-shadow:3px 0 16px #0002;padding:20px 24px}.mobile-drawer.is-open{transform:translateX(0);visibility:visible;pointer-events:auto}.drawer-head{display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);padding-bottom:12px;color:var(--heading)}.drawer-close{border:0;background:#edf3f7;border-radius:8px;width:40px;height:40px;font-size:27px;line-height:1}.mobile-drawer nav p{margin:22px 0 4px;font-size:12px;color:#6b8390;font-weight:800}.mobile-drawer nav a{display:block;padding:10px 12px;border-radius:7px;color:#264a61;font-weight:600}.mobile-drawer nav a[aria-current=page]{border-left:3px solid var(--teal);background:#eaf7f9;font-weight:800}.nojs-nav{display:none}noscript .nojs-nav{display:flex;flex-wrap:wrap;gap:8px 17px;padding:10px 0;font-size:14px}.mobile-quick{display:flex;gap:10px 19px;flex-wrap:wrap;justify-content:center;margin-bottom:30px;padding:16px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);font-size:13px}.hero{gap:22px}}
@media(max-width:760px){.hero,.editorial-split,.editorial-split.reverse,.asym-grid,.gallery-pair,.gallery-pair.offset,.content-with-aside,.rule-handbook,.service-layout{display:grid;grid-template-columns:minmax(0,1fr)}.editorial-split.reverse .media-frame,.editorial-split.reverse .split-copy,.gallery-pair.offset .media-frame,.gallery-pair.offset .gallery-copy{grid-column:auto;grid-row:auto}.hero{padding-top:10px}.hero .media-frame{max-width:640px;margin:auto}.content-with-aside .info-aside{order:2}.service-menu{position:static;order:2}.rule-index{position:static}.rule-teasers,.metric-matrix,.tactic-cards{grid-template-columns:1fr 1fr}.route-steps,.step-flow{grid-template-columns:1fr 1fr}.footer-layout{gap:25px}.topic-directory .directory-grid{gap:0 23px}}
@media(max-width:640px){.container{width:calc(100% - 32px)}body{font-size:15px;line-height:1.8}h1{font-size:27px}h2{font-size:21px}h3{font-size:18px}.hero h1{font-size:30px}.lead{font-size:15.5px}.page-content{padding-top:19px;padding-bottom:42px}section+section{margin-top:37px}.topic-directory .directory-grid,.rule-teasers,.metric-matrix,.tactic-cards,.related-list,.footer-layout{grid-template-columns:1fr}.directory-item{padding:12px 0}.rule-teasers article:nth-child(n){margin-top:0}.writing-band,.feature-main{padding:22px}.side-stack article,.soft-panel{padding:18px}.hero-links{gap:9px}.button-primary,.button-outline{padding:9px 13px;font-size:13px}.media-frame--hero{--media-limit:205px}.media-frame--feature{--media-limit:185px}.media-frame--article{--media-limit:175px}.media-frame--card{--media-limit:145px}.media-frame--wide{--media-limit:135px}.media-frame--mobile{--media-limit:285px;max-width:250px}.media-frame--logo img{max-height:30px}.page-intro{padding:7px 0 12px}.step-flow,.route-steps{grid-template-columns:1fr 1fr;gap:9px}.step-flow article{padding:13px}.route-steps article{padding:10px 4px}.footer-bottom{display:block}.footer-bottom a{display:block;margin-top:9px}.site-footer{padding-top:30px}.related-links{margin-top:38px}.faq-list details{padding:0 12px}}
@media(max-width:380px){.brand-inner{gap:5px}.brand{max-width:44vw}.entry-link{padding:6px 8px;font-size:11px}.brand .media-frame--logo.media-missing{width:110px}.step-flow,.route-steps{grid-template-columns:1fr}.anchor-nav{gap:7px}.anchor-nav a{font-size:12px;padding:4px 9px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important}}
