:root{--bg:#F6FAFC;--white:#fff;--pale:#EAF6FA;--pale2:#EDF4F8;--cyan:#25C8D1;--sky:#25B6E8;--blue:#1787DB;--sea:#174B78;--head:#183A56;--text:#31485D;--mute:#687D8E;--border:#DCE9F0;--footer:#123653;--radius:16px}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:32px}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif;overflow-x:hidden}a{color:var(--sea);text-underline-offset:4px}a:hover{color:#087aa7}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--sky);outline-offset:3px}img{max-width:100%}h1,h2,h3{color:var(--head);line-height:1.36;margin:0 0 .65em}h1{font-size:clamp(32px,3.3vw,42px);letter-spacing:-.025em}h2{font-size:26px}h3{font-size:20px}p{margin:.65em 0 1.15em}ul,ol{padding-left:1.35em}li+li{margin-top:.35em}.container{width:min(100% - 56px,1180px);margin:auto}.section{margin:58px auto}.section-heading{margin-bottom:25px}.eyebrow{font-size:13px;font-weight:800;letter-spacing:.13em;color:#087e9d;text-transform:uppercase}.lead{font-size:17px;line-height:1.82;color:#415d70}.muted{color:var(--mute)}.skip-link{position:absolute;left:10px;top:-80px;z-index:30;padding:8px;background:#fff}.skip-link:focus{top:10px}.site-header{position:relative;z-index:10;background:#fff;border-bottom:1px solid var(--border)}.topbar{height:72px;display:flex;align-items:center;gap:24px}.brand{display:flex;align-items:center;min-width:0;text-decoration:none;color:var(--head)}.brand img{width:auto;height:auto;max-height:38px;max-width:215px;object-fit:contain}.brand-word{font-size:23px;font-weight:800;line-height:1.1}.brand-word small,.footer-brand small{display:block;font-size:10px;letter-spacing:.1em}.header-tagline{margin:auto;color:var(--mute);font-size:13px}.entry{border-radius:8px;background:var(--sea);color:#fff;display:inline-flex;align-items:center;justify-content:center;min-height:42px;padding:0 23px;text-decoration:none;font-weight:700;white-space:nowrap}.entry:hover{background:#0966a5;color:#fff}.desktop-nav{background:var(--sea)}.nav-line{display:flex;align-items:stretch;justify-content:space-between;gap:8px;min-height:48px}.nav-line a{display:flex;align-items:center;justify-content:center;padding:9px 12px;border-bottom:3px solid transparent;text-decoration:none;color:#e5f6ff;font-weight:600;white-space:nowrap;font-size:15px}.nav-line a:hover,.nav-line a[aria-current]{border-color:var(--cyan);color:#fff;background:#22618e}.menu-toggle{display:none;flex-direction:column;gap:4px;justify-content:center;align-items:center;width:40px;height:40px;border:1px solid var(--border);border-radius:8px;background:#fff;cursor:pointer}.menu-toggle span{width:19px;height:2px;background:var(--sea)}.menu-overlay{position:fixed;inset:0;background:rgba(8,35,53,.44);z-index:25;visibility:hidden;opacity:0;pointer-events:none;transition:opacity .2s}.mobile-menu{position:fixed;top:0;bottom:0;left:0;width:min(86vw,344px);background:#fff;box-shadow:8px 0 32px #12365329;transform:translateX(-105%);visibility:hidden;pointer-events:none;z-index:26;overflow-y:auto;padding:24px;transition:transform .2s,visibility .2s}.menu-open{overflow:hidden}.menu-open .menu-overlay{visibility:visible;pointer-events:auto;opacity:1}.menu-open .mobile-menu{visibility:visible;pointer-events:auto;transform:none}.drawer-heading{display:flex;align-items:center;justify-content:space-between;font-size:20px;color:var(--head);padding-bottom:16px;border-bottom:1px solid var(--border)}.menu-close{width:40px;height:40px;border:0;background:var(--pale);border-radius:8px;cursor:pointer;font-size:26px;color:var(--sea)}.drawer-group{display:flex;flex-direction:column;gap:3px;padding:19px 0;border-bottom:1px solid var(--border)}.drawer-group strong{color:var(--mute);font-size:13px}.drawer-group a{padding:6px 10px;text-decoration:none;border-radius:6px}.drawer-group a:hover{background:var(--pale)}.quick-strip{background:#edf7fa;border-bottom:1px solid var(--border)}.quick-groups{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:11px 0;font-size:13px}.quick-groups span{display:flex;gap:11px;flex-wrap:wrap}.quick-groups b{color:var(--head)}.quick-groups a{text-decoration:none}.page-hero{padding:47px 0 12px}.page-hero h1{font-size:clamp(30px,3vw,36px);max-width:910px}.page-hero .lead{max-width:890px}.home-hero{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(0,.88fr);gap:38px;align-items:center;padding:58px 0 20px}.home-hero .lead{max-width:620px}.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:24px}.btn{display:inline-flex;align-items:center;justify-content:center;min-height:44px;padding:10px 19px;border-radius:9px;text-decoration:none;font-weight:700}.btn-primary{background:var(--sea);color:white}.btn-primary:hover{background:#086c9a;color:white}.btn-quiet{background:#e3f1f7;color:var(--sea)}.media{display:flex;justify-content:center;align-items:center;width:100%;min-width:0;overflow:hidden;border-radius:14px;background:var(--pale);margin:0}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media--hero{height:clamp(250px,26vw,330px)}.media--feature{height:250px}.media--card{height:170px}.media--banner{height:220px}.media--mobile{height:350px;max-width:320px}.media--wide{background:#edf4f8}.media--portrait{max-width:360px;margin-inline:auto}.media--missing{background:linear-gradient(135deg,#eaf6fa,#edf4f8);border:1px solid var(--border)}.topic-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:15px}.topic-grid a{background:#fff;padding:23px;border:1px solid var(--border);border-radius:14px;text-decoration:none;transition:border-color .15s}.topic-grid a:hover{border-color:#72cbdd}.topic-grid h3{font-size:18px;margin:0 0 7px}.topic-grid p{font-size:14px;margin:0;color:var(--mute)}.editor-grid{display:grid;grid-template-columns:2fr 1fr;gap:20px}.panel,.card{background:#fff;border:1px solid var(--border);border-radius:var(--radius);padding:26px}.panel h3,.card h3{margin-top:0}.editor-side{display:grid;gap:20px}.feature-row{display:grid;grid-template-columns:1fr 1fr;gap:34px;align-items:center}.feature-row.reverse>.media{order:-1}.strip-section{background:#eaf6fa;padding:40px 0}.text-three{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}.text-three article{border-left:3px solid var(--cyan);padding:0 18px}.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:15px;counter-reset:steps}.steps article{padding:20px;border-top:3px solid var(--sky);background:#fff;border-radius:9px}.steps article:before{counter-increment:steps;content:'0' counter(steps);display:block;color:#087e9d;font-size:23px;font-weight:800}.note{background:var(--pale);padding:20px 25px;border-left:4px solid var(--cyan);border-radius:7px}.reading-layout{display:grid;grid-template-columns:minmax(0,760px) minmax(0,240px);gap:36px;align-items:start}.prose{max-width:780px}.prose h2,.page-content h2{margin-top:30px}.prose p,.page-content p{line-height:1.83}.aside-box{background:#eaf6fa;border-radius:12px;padding:22px;position:sticky;top:20px}.aside-box h2{font-size:19px}.aside-box dt{font-weight:700;color:var(--head);margin-top:10px}.aside-box dd{margin:0;font-size:14px}.table-scroll{max-width:100%;overflow-x:auto;border:1px solid var(--border);border-radius:12px}.data-table{border-collapse:collapse;width:100%;min-width:560px;background:#fff}.data-table th,.data-table td{padding:14px 17px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}.data-table th{background:#eaf6fa;color:var(--head);font-weight:800}.data-table tr:last-child td{border-bottom:0}.matrix{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.matrix article{padding:23px;background:#fff;border:1px solid var(--border);border-radius:12px}.matrix h3{color:var(--sea)}.gallery-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}.gallery-grid article{background:#fff;padding:16px;border:1px solid var(--border);border-radius:12px}.gallery-grid h3{margin:15px 4px 5px}.gallery-grid p{margin:0 4px 8px}.toc{display:flex;flex-wrap:wrap;gap:10px;padding:13px 0}.toc a{padding:8px 13px;background:#e5f3f7;border-radius:8px;text-decoration:none;font-weight:700;font-size:14px}.section-divider{border:0;border-top:1px solid var(--border);margin:38px 0}.related{margin:60px 0 58px;padding-top:20px;border-top:2px solid var(--border)}.related-links{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.related-links a{padding:17px;background:#fff;border:1px solid var(--border);border-radius:9px;text-decoration:none;font-weight:700}.faq-list{display:grid;gap:10px}.faq-list details{background:#fff;border:1px solid var(--border);border-radius:10px;padding:0 18px}.faq-list summary{padding:15px 0;cursor:pointer;font-weight:700;color:var(--head)}.faq-list details p{margin:0;padding:0 0 17px}.site-footer{background:var(--footer);color:#eaf7ff;padding:46px 0 20px}.footer-layout{display:grid;grid-template-columns:1.3fr 1fr;gap:44px}.footer-layout p{max-width:590px;color:#d0e6f1;font-size:14px}.footer-brand{font-size:21px}.footer-links{display:grid;grid-template-columns:repeat(2,1fr);gap:5px 16px;margin-top:12px}.footer-links a{color:#eaf7ff;font-size:14px}.footer-bottom{border-top:1px solid #ffffff2e;margin-top:30px;padding-top:12px;font-size:13px;color:#d2e3ea}.back-top{position:fixed;right:18px;bottom:18px;width:44px;height:44px;border-radius:50%;background:var(--sea);color:#fff;border:0;cursor:pointer;z-index:8;opacity:0;pointer-events:none;transition:opacity .2s}.back-top.visible{opacity:1;pointer-events:auto}.bottom-nav{display:none}
@media(max-width:980px){.desktop-nav{display:none}.menu-toggle{display:flex}.topbar{height:62px;gap:11px}.topbar .brand{margin:auto}.brand img{max-height:30px;max-width:155px}.brand-word{font-size:19px}.entry{min-height:40px;padding:0 13px;font-size:14px}.header-tagline{display:none}.quick-groups{flex-wrap:wrap}.container{width:min(100% - 44px,1180px)}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.reading-layout{grid-template-columns:minmax(0,1fr)}.aside-box{position:static}.section{margin:42px auto}}
@media(max-width:760px){.home-hero,.feature-row,.editor-grid,.footer-layout{grid-template-columns:1fr}.home-hero{gap:20px;padding-top:35px}.home-hero>.media{grid-row:1}.feature-row.reverse>.media{order:0}.matrix,.text-three,.steps{grid-template-columns:1fr 1fr}.related-links{grid-template-columns:1fr}.quick-groups{gap:7px}.quick-groups span{width:100%}.section{margin:35px auto}.page-hero{padding-top:32px}}
@media(max-width:640px){body{font-size:15px}.container{width:calc(100% - 32px)}h1{font-size:clamp(27px,7vw,31px)}h2{font-size:22px}h3{font-size:18px}.page-hero h1{font-size:clamp(25px,6.6vw,29px)}.lead{font-size:15.5px}.media--hero{height:200px}.media--feature{height:180px}.media--card{height:145px}.media--banner{height:150px}.media--mobile{height:290px;max-width:250px}.topic-grid,.matrix,.gallery-grid,.text-three,.steps{grid-template-columns:1fr}.topic-grid a{padding:17px}.panel,.card{padding:19px}.site-footer{padding-bottom:91px}.bottom-nav{display:grid;grid-template-columns:repeat(4,1fr);position:fixed;bottom:0;left:0;right:0;z-index:9;background:#fff;border-top:1px solid var(--border);padding:7px 8px calc(7px + env(safe-area-inset-bottom));box-shadow:0 -3px 15px #12365312}.bottom-nav a{text-align:center;text-decoration:none;font-size:13px;font-weight:700;padding:7px 2px}.back-top{bottom:82px}.quick-groups{padding:8px 0}.quick-groups b{margin-right:3px}.topbar{gap:6px}.brand img{max-width:137px}.entry{padding:0 10px;font-size:12px}.footer-links{grid-template-columns:1fr 1fr}}@media(max-height:480px) and (max-width:640px){.bottom-nav{position:static}.site-footer{padding-bottom:20px}.back-top{bottom:18px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}

.nojs-nav{display:flex;flex-wrap:wrap;gap:12px;padding-block:13px}.nojs-nav a{font-size:14px;font-weight:700}.menu-open .mobile-menu{overscroll-behavior:contain}