:root{--bg:#F4F7FA;--white:#fff;--pale:#EAF1F6;--aqua:#E9F8F8;--navy:#102E46;--navy2:#163C57;--teal:#13B8C5;--blue:#237BD3;--heading:#18364B;--text:#344C60;--muted:#64798A;--line:#DCE6ED;--radius:14px;--max:1200px}
*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:25px}body{margin:0;background:var(--bg);font:16px/1.8 Arial,"PingFang SC","Microsoft YaHei",sans-serif;color:var(--text);overflow-wrap:break-word}body.drawer-open{overflow:hidden}a{color:var(--blue);text-underline-offset:4px}a:hover{color:#155BA5}button{font:inherit}img{max-width:100%;height:auto}figure{margin:0}h1,h2,h3,h4,p{margin-top:0}h1,h2,h3{color:var(--heading);line-height:1.38}h1{font-size:clamp(2rem,3vw,2.25rem);letter-spacing:-.025em}h2{font-size:clamp(1.5rem,2vw,1.75rem)}h3{font-size:1.2rem}p{margin-bottom:1.05em}ul,ol{padding-left:1.5em}li+li{margin-top:.35em}strong{color:var(--heading)}.container{width:min(calc(100% - 56px),var(--max));margin-inline:auto}.reading{max-width:800px}.eyebrow{display:block;font-weight:700;font-size:.78rem;letter-spacing:.12em;text-transform:uppercase;color:#167C91;margin-bottom:14px}.subtle{color:var(--muted)}.section{margin-block:60px}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:20px;margin-bottom:23px}.section-heading h2{margin:0}.section-heading p{max-width:540px;margin:0}.skip-link{position:absolute;z-index:120;top:-100px;left:15px;background:#fff;padding:10px}.skip-link:focus{top:8px}:focus-visible{outline:3px solid #15B5C7;outline-offset:3px}
.site-header{position:relative;z-index:20}.brand-bar{background:#fff;border-bottom:1px solid var(--line)}.brand-inner{height:72px;display:flex;align-items:center;gap:24px}.brand{display:inline-flex;align-items:center;flex:none;max-width:230px;text-decoration:none}.brand img{display:block;width:auto;height:auto;max-height:38px;max-width:225px;object-fit:contain}.brand-text{font-size:1.5rem;color:var(--navy)}.brand-caption{font-size:.8rem;color:var(--muted);border-left:1px solid var(--line);padding-left:22px}.entry-button{margin-left:auto;color:#fff;text-decoration:none;font-size:.9rem;font-weight:700;border-radius:9px;background:var(--navy);padding:8px 21px;min-height:40px;display:inline-flex;align-items:center;justify-content:center;white-space:nowrap}.entry-button:hover{background:#24617d;color:#fff}.desktop-nav{background:var(--navy)}.desktop-nav ul{width:min(calc(100% - 56px),var(--max));margin:0 auto;padding:0;list-style:none;display:grid;grid-template-columns:repeat(7,minmax(0,1fr))}.desktop-nav li{margin:0;min-width:0}.desktop-nav a{height:50px;color:#DCECF5;text-decoration:none;display:flex;align-items:center;justify-content:center;font-size:.9rem;font-weight:600;position:relative;white-space:nowrap;padding:0 8px}.desktop-nav a:hover,.desktop-nav a[aria-current=page]{color:#fff;background:#163C57}.desktop-nav a[aria-current=page]::after{content:"";position:absolute;bottom:0;width:30px;height:3px;border-radius:3px;background:var(--teal)}.menu-toggle,.drawer-overlay,.mobile-drawer,.noscript-navigation,.mobile-quicklinks{display:none}
.site-footer{background:#0B2539;color:#DCECF5;padding:45px 0 18px}.site-footer strong,.site-footer .footer-title{color:#fff}.footer-layout{display:grid;grid-template-columns:1.5fr 1fr;gap:80px}.footer-layout p{max-width:570px;font-size:.9rem;margin:14px 0;line-height:1.85}.footer-title{font-weight:800;font-size:1.4rem}.footer-title small{font-size:.72rem;letter-spacing:.14em;font-weight:500;display:block;color:#AFC7D8}.footer-nav{display:flex;flex-wrap:wrap;align-content:start;gap:8px 20px}.footer-nav strong{flex-basis:100%}.footer-nav a{color:#DCECF5;text-decoration:none;font-size:.85rem}.footer-nav a:hover{color:#6FE1E6}.footer-bottom{border-top:1px solid #315065;padding-top:15px;margin-top:26px;display:flex;justify-content:space-between;gap:15px;color:#AAC2D2;font-size:.79rem}.to-top{position:fixed;z-index:15;right:22px;bottom:22px;border:0;background:var(--navy);color:#fff;border-radius:50%;width:42px;height:42px;cursor:pointer;box-shadow:0 4px 14px #0002}.to-top[hidden]{display:none}
.page-lead{background:#fff;border-bottom:1px solid var(--line);padding:44px 0 36px}.page-lead .intro{max-width:825px;font-size:1.06rem}.page-lead h1{margin-bottom:14px}.breadcrumbs{font-size:.79rem;color:var(--muted);margin-bottom:14px}.breadcrumbs a{color:var(--muted)}.cover{margin:36px 0 62px;display:grid;grid-template-columns:52fr 48fr;align-items:center;gap:28px}.cover-copy{padding:30px 10px 28px 0}.cover h1{font-size:clamp(2rem,3.4vw,2.75rem);line-height:1.35;margin-bottom:22px}.cover p{font-size:1.06rem;max-width:610px}.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:25px}.btn{display:inline-flex;justify-content:center;align-items:center;min-height:44px;padding:9px 21px;border-radius:9px;background:var(--navy);color:#fff;text-decoration:none;font-weight:700;font-size:.9rem}.btn:hover{background:var(--navy2);color:#fff}.btn-outline{background:#fff;color:var(--navy);border:1px solid #b5c9d7}.btn-outline:hover{color:var(--navy);background:var(--pale)}
.media-frame{display:flex;justify-content:center;align-items:center;min-width:0;width:100%;padding:10px;background:var(--pale);border-radius:var(--radius);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--mobile{--media-limit:350px;max-width:320px;margin-inline:auto}.media-frame--banner{--media-limit:210px}.media-placeholder{min-height:120px;max-height:220px;display:flex;flex-direction:column;gap:2px;align-items:center;justify-content:center;width:100%;border:1px dashed #b2c9d5;border-radius:10px;color:#587688;text-align:center;padding:20px;background:linear-gradient(135deg,#eff5f8,#e5f0f4)}.media-placeholder span{font-size:.95rem;font-weight:700}.media-placeholder small{font-size:.7rem}.cover .media-placeholder{min-height:215px}
.topic-index{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 36px;border-top:2px solid var(--navy)}.topic-item{padding:20px 8px 22px 0;border-bottom:1px solid var(--line);display:grid;grid-template-columns:36px 1fr;gap:14px}.topic-item .number{font-weight:800;color:#1e8c9d}.topic-item h3{font-size:1.13rem;margin-bottom:5px}.topic-item p{font-size:.91rem;margin-bottom:10px}.topic-item a{font-size:.9rem;font-weight:700}.editor-grid{display:grid;grid-template-columns:2fr 1fr;gap:18px}.editor-feature{background:#fff;border-radius:var(--radius);padding:30px;border-top:4px solid var(--teal)}.editor-side{display:grid;gap:18px}.editor-minor{padding:25px;background:var(--aqua);border-radius:var(--radius)}.editor-minor:last-child{background:var(--pale)}.editor-minor h3{margin-bottom:10px}.editor-feature p,.editor-minor p{font-size:.95rem}.split-feature{display:grid;grid-template-columns:45fr 55fr;align-items:center;gap:35px;background:#fff;padding:26px;border-radius:var(--radius)}.split-feature.reverse{grid-template-columns:55fr 45fr}.split-feature h2{margin-bottom:14px}.dark-band{background:var(--navy);color:#E2F0F6;padding:35px;border-radius:var(--radius)}.dark-band h2,.dark-band h3,.dark-band strong{color:#fff}.dark-band p{color:#D0E0EA}.mini-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.mini-note{background:#fff;padding:23px;border:1px solid var(--line);border-radius:11px}.mini-note h3{font-size:1.1rem;margin-bottom:10px}.route{display:grid;grid-template-columns:repeat(4,1fr);gap:0;counter-reset:route}.route-step{border-top:2px solid var(--teal);padding:20px 16px 5px 0;position:relative}.route-step::before{counter-increment:route;content:'0' counter(route);display:block;color:#098c98;font-weight:800;font-size:1.25rem;margin-bottom:8px}.route-step a{font-weight:700}.editor-note{border-left:3px solid var(--teal);padding:15px 23px;background:var(--aqua);font-size:.93rem}
.article-layout{display:grid;grid-template-columns:minmax(0,1fr) 235px;gap:46px;align-items:start}.article-layout>.article-body{min-width:0}.article-body{font-size:1.02rem}.article-body h2{margin:35px 0 16px}.article-body h3{margin:27px 0 10px}.article-body p{line-height:1.83}.article-body section{scroll-margin-top:30px}.article-aside{background:var(--pale);padding:23px;border-radius:var(--radius);font-size:.85rem}.article-aside h3{font-size:1rem}.article-aside a{display:block;padding:6px 0}.content-panel{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px}.content-panel h2:first-child{margin-top:0}.plain-list{padding-left:21px}.plain-list li{margin-bottom:10px}.callout{padding:21px 24px;background:var(--aqua);border-left:3px solid var(--teal);border-radius:0 9px 9px 0;margin:24px 0}.callout p:last-child{margin-bottom:0}.section-rule{border:0;border-top:1px solid var(--line);margin:36px 0}.table-scroll{overflow-x:auto;border:1px solid var(--line);border-radius:12px;background:#fff;margin:20px 0 30px}.data-table{border-collapse:collapse;width:100%;min-width:570px;font-size:.91rem;line-height:1.65}.data-table caption{text-align:left;padding:14px 18px;font-weight:800;color:var(--heading);background:#EAF1F6}.data-table th,.data-table td{text-align:left;vertical-align:top;padding:13px 16px;border-bottom:1px solid var(--line)}.data-table thead th{background:#EAF1F6;color:var(--heading)}.data-table tr:last-child td{border-bottom:0}.steps{counter-reset:steps;display:grid;gap:12px}.step{counter-increment:steps;display:grid;grid-template-columns:46px 1fr;gap:16px;padding:17px 18px;background:#fff;border:1px solid var(--line);border-radius:10px}.step::before{content:counter(steps,decimal-leading-zero);font-size:1.2rem;font-weight:800;color:#078e9a}.step h3{margin:0 0 4px}.step p{margin:0;font-size:.94rem}.related{margin:55px 0}.related h2{margin-bottom:16px}.related-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:13px}.related-link{background:#fff;border:1px solid var(--line);border-radius:11px;padding:20px;text-decoration:none;display:flex;flex-direction:column;position:relative;gap:7px}.related-link strong{font-size:1rem}.related-link span:not(.link-arrow){color:var(--muted);font-size:.85rem}.related-link .link-arrow{position:absolute;top:15px;right:16px}.related-link:hover{border-color:var(--teal)}.anchor-tabs{display:flex;flex-wrap:wrap;gap:9px;margin-top:25px}.anchor-tabs a{padding:8px 15px;border-radius:30px;text-decoration:none;border:1px solid #BDD3DE;background:#fff;color:var(--heading);font-size:.86rem;font-weight:700}.anchor-tabs a:hover{background:var(--aqua)}.section-intro{max-width:830px;margin-bottom:28px}.alternating{display:grid;grid-template-columns:1fr 1fr;gap:28px;align-items:center}.alternating>div{min-width:0}.text-columns{columns:2;column-gap:36px}.text-columns p{break-inside:avoid}.stat-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.stat-strip>div{background:#fff;border-top:3px solid var(--teal);padding:21px}.stat-strip strong{display:block;font-size:1.1rem}.exhibit-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}.exhibit{background:#fff;padding:18px;border:1px solid var(--line);border-radius:var(--radius)}.exhibit:nth-child(2){margin-top:36px}.exhibit h3{margin:17px 0 8px}.exhibit p{font-size:.94rem}.manual-section{padding:30px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);margin:24px 0}.manual-section h2{margin:0 0 17px}.faq-list{display:grid;gap:9px}.faq-list details{background:#fff;border:1px solid var(--line);border-radius:10px;overflow:hidden}.faq-list summary{padding:15px 20px;cursor:pointer;font-weight:700;color:var(--heading);list-style-position:inside}.faq-list details[open] summary{background:var(--pale)}.faq-list .answer{padding:15px 20px 17px}.faq-list .answer p{margin:0}.about-layout{display:grid;grid-template-columns:240px minmax(0,1fr);gap:35px}.about-side{background:var(--navy);color:#fff;border-radius:12px;padding:20px;align-self:start}.about-side strong{color:#fff}.about-side a{display:block;color:#d9f1f5;text-decoration:none;padding:9px 4px;border-bottom:1px solid #34566b;font-size:.9rem}.about-content{min-width:0}.about-content section{margin-bottom:35px}.end-cta{margin:50px 0 65px}.muted-small{font-size:.84rem;color:var(--muted)}
@media(max-width:1024px){.container{width:min(calc(100% - 44px),var(--max))}.desktop-nav ul{width:min(calc(100% - 44px),var(--max))}.desktop-nav a{font-size:.84rem}.cover{gap:18px}.section{margin-block:48px}.article-layout{gap:24px;grid-template-columns:minmax(0,1fr) 200px}}
@media(max-width:920px){.brand-inner{height:62px;display:grid;grid-template-columns:40px minmax(0,1fr) auto;gap:12px}.brand{justify-self:center;max-width:calc(100% - 6px)}.brand img{max-height:30px;max-width:100%}.brand-text{font-size:1.2rem}.brand-caption,.desktop-nav{display:none}.entry-button{height:40px;padding:6px 11px;margin:0;font-size:.8rem}.menu-toggle{display:flex;width:40px;height:40px;border:1px solid var(--line);background:#fff;border-radius:8px;flex-direction:column;justify-content:center;align-items:center;gap:5px;cursor:pointer}.menu-toggle span{width:19px;height:2px;background:var(--navy)}.drawer-overlay{display:block;position:fixed;inset:0;background:rgba(6,22,34,.55);opacity:0;visibility:hidden;pointer-events:none;transition:opacity .22s,visibility .22s;z-index:60}.drawer-overlay.is-open{opacity:1;visibility:visible;pointer-events:auto}.mobile-drawer{display:block;position:fixed;z-index:61;top:0;left:0;bottom:0;width:min(86vw,340px);background:#fff;overflow-y:auto;padding:20px 23px;transform:translateX(-102%);visibility:hidden;transition:transform .22s,visibility .22s;box-shadow:3px 0 15px #0002}.mobile-drawer.is-open{transform:translateX(0);visibility:visible}.drawer-head{display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);padding-bottom:12px}.drawer-head strong{font-size:1.1rem}.drawer-close{background:var(--pale);border:0;border-radius:8px;font-size:1.7rem;width:40px;height:40px;cursor:pointer;line-height:1}.drawer-group{margin-top:20px}.drawer-group p{font-size:.75rem;color:var(--muted);font-weight:700;letter-spacing:.1em;margin-bottom:6px}.drawer-group a{display:block;padding:11px 12px;text-decoration:none;color:var(--heading);border-radius:7px}.drawer-group a:hover{background:var(--pale)}.noscript-navigation{display:none;flex-wrap:wrap;gap:5px;padding:10px 22px;background:var(--navy)}.noscript-navigation a{color:#fff;font-size:.83rem;padding:5px 7px}.mobile-quicklinks{display:flex;flex-wrap:wrap;gap:8px 16px;padding:20px 0;margin-top:15px;font-size:.82rem}.mobile-quicklinks span{color:var(--muted);flex-basis:100%}.cover{margin-top:25px}.footer-layout{gap:35px}}
@media(max-width:760px){.cover,.split-feature,.split-feature.reverse,.alternating,.editor-grid,.article-layout,.about-layout{grid-template-columns:1fr}.cover{gap:17px}.cover-copy{padding:0}.split-feature.reverse .media-frame{order:0}.split-feature.reverse>div:not(.media-frame){order:1}.editor-side{grid-template-columns:1fr 1fr}.article-aside{display:none}.related-links{grid-template-columns:1fr 1fr}.mini-grid,.stat-strip{grid-template-columns:1fr}.about-side{order:2}.about-content{order:1}.page-lead{padding:30px 0}.text-columns{columns:1}.route{grid-template-columns:repeat(2,1fr);gap:14px}}
@media(max-width:640px){body{font-size:15px;line-height:1.78}.container{width:calc(100% - 32px)}h1{font-size:clamp(1.6rem,6vw,1.82rem)}h2{font-size:1.36rem}h3{font-size:1.1rem}.cover h1{font-size:clamp(1.72rem,7vw,2rem)}.cover p,.page-lead .intro{font-size:1rem}.section{margin-block:36px}.section-heading{display:block}.section-heading p{margin-top:9px}.topic-index,.editor-side,.exhibit-grid,.related-links{grid-template-columns:1fr}.editor-feature,.editor-minor,.content-panel,.manual-section{padding:19px}.exhibit:nth-child(2){margin-top:0}.split-feature{padding:18px;gap:19px}.dark-band{padding:23px}.media-frame--hero{--media-limit:205px}.media-frame--feature{--media-limit:185px}.media-frame--card{--media-limit:145px}.media-frame--mobile{--media-limit:285px;max-width:250px}.media-frame--banner{--media-limit:135px}.cover .media-placeholder{min-height:150px}.media-placeholder{min-height:110px}.section-heading h2{margin-bottom:4px}.route{grid-template-columns:1fr}.route-step{padding-bottom:0}.article-body{font-size:1rem}.article-body h2{margin-top:27px}.footer-layout{grid-template-columns:1fr;gap:20px}.footer-bottom{display:block}.footer-bottom span{display:block}.step{grid-template-columns:36px 1fr;padding:14px}.anchor-tabs{gap:7px}.anchor-tabs a{font-size:.82rem;padding:7px 11px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition-duration:.01ms!important;animation-duration:.01ms!important}}