:root{--bg:#f5fbff;--paper:#fff;--soft:#eaf7fc;--pale:#dff5fb;--cyan:#25c8d1;--sky:#25b6e8;--blue:#1787db;--navy:#174b78;--ink:#173b60;--body:#2d4359;--muted:#687f93;--line:#dcebf3;--footer:#123653;--shadow:0 16px 45px rgba(22,89,128,.075)}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:92px}body{margin:0;font-family:Arial,'PingFang SC','Microsoft YaHei',sans-serif;background:var(--bg);color:var(--body);font-size:16px;line-height:1.8}a{color:inherit;text-decoration:none}button{font:inherit;cursor:pointer}a:focus-visible,button:focus-visible{outline:3px solid var(--blue);outline-offset:3px}img{max-width:100%}.wrap{width:min(1160px,calc(100% - 48px));margin-inline:auto}.skip-link{position:absolute;left:12px;top:-100px;background:var(--ink);color:white;z-index:60;padding:8px 16px}.skip-link:focus{top:10px}.site-header{position:sticky;top:0;z-index:30;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 3px 18px rgba(17,69,105,.035)}.header-inner{height:72px;display:flex;align-items:center;gap:28px}.brand{display:flex;gap:9px;align-items:center;flex-shrink:0;color:var(--ink)}.brand img{display:block;width:auto;height:37px;max-width:174px;object-fit:contain}.brand-symbol{background:linear-gradient(135deg,var(--cyan),var(--blue));border-radius:11px;color:white;display:grid;place-items:center;width:41px;height:41px;font-size:26px;font-weight:900;font-style:italic}.brand-type{font-weight:900;font-size:20px;letter-spacing:.06em;white-space:nowrap;line-height:1.2}.brand-type small{display:block;letter-spacing:.12em;color:var(--blue);font-size:9px}.desktop-nav{margin-left:auto;display:flex;align-items:center;gap:4px;height:100%}.desktop-nav a{white-space:nowrap;font-size:14px;font-weight:700;padding:12px 10px;border-radius:9px;color:var(--navy);line-height:1.2}.desktop-nav a:hover,.desktop-nav a[aria-current]{background:var(--soft);color:#087fa9}.main-btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-width:82px;height:42px;padding:0 20px;border-radius:999px;background:linear-gradient(110deg,#25c8d1,#25b6e8,#1787db);color:#fff;font-weight:700;white-space:nowrap;box-shadow:0 9px 22px rgba(23,135,219,.17)}.main-btn:hover{filter:brightness(.96);transform:translateY(-1px)}.header-entry{font-size:14px}.menu-toggle{display:none;background:none;border:0;padding:8px;width:42px;height:42px;flex-direction:column;justify-content:center;gap:5px}.menu-toggle span{display:block;width:23px;height:2px;background:var(--ink);border-radius:3px}.drawer-mask{position:fixed;inset:0;background:rgba(12,39,59,.48);z-index:38;visibility:hidden;opacity:0;pointer-events:none;transition:opacity .2s,visibility .2s}.mobile-drawer{position:fixed;z-index:39;left:0;top:0;bottom:0;width:min(86vw,340px);overflow-y:auto;transform:translateX(-101%);transition:transform .23s;background:#fff;box-shadow:15px 0 35px rgba(0,0,0,.12);padding:18px 22px;visibility:hidden}.menu-open{overflow:hidden}.menu-open .drawer-mask{visibility:visible;opacity:1;pointer-events:auto}.menu-open .mobile-drawer{visibility:visible;transform:translateX(0)}.drawer-heading{display:flex;justify-content:space-between;align-items:center;font-size:20px;color:var(--ink);padding-bottom:16px;border-bottom:1px solid var(--line)}.drawer-close{border:0;background:var(--soft);border-radius:50%;font-size:27px;width:38px;height:38px;line-height:1}.drawer-group{border-bottom:1px solid var(--line);padding:9px 0 12px}.drawer-group p{font-size:12px;font-weight:700;letter-spacing:.08em;color:var(--blue);margin:7px 0}.drawer-group a{display:block;color:var(--body);padding:8px 0;font-size:15px}.drawer-entry{width:100%;margin-top:22px}.bottom-nav{display:none}h1,h2,h3{color:var(--ink);line-height:1.36;margin:0 0 18px}h1{font-size:38px;letter-spacing:-.02em}h2{font-size:25px}h3{font-size:19px}p{margin:0 0 16px}section{margin-block:38px}.eyebrow{font-size:12px;color:#117baf;letter-spacing:.14em;text-transform:uppercase;font-weight:800;margin-bottom:15px}.lead{font-size:17px;max-width:790px;color:#496782;line-height:1.85}.hero{position:relative;display:grid;grid-template-columns:1fr 43%;align-items:center;gap:38px;background:linear-gradient(125deg,#e0f5fc 0%,#fafdff 65%,#e9f6ff 100%);border:1px solid #d6edf7;border-radius:22px;padding:54px 54px 48px;overflow:hidden;margin-top:30px}.hero:before{content:'';position:absolute;right:-90px;top:-140px;width:350px;height:350px;border-radius:50%;border:50px solid rgba(37,182,232,.055);pointer-events:none}.hero h1{max-width:650px}.hero p{max-width:650px}.hero .hero-actions{display:flex;flex-wrap:wrap;gap:14px;margin-top:26px}.ghost-btn{border:1px solid #a6d7ed;border-radius:999px;padding:8px 20px;color:var(--navy);font-weight:700;display:inline-flex;align-items:center}.hero-media{height:290px}.media{display:flex;justify-content:center;align-items:center;width:100%;overflow:hidden;background:#eaf7fc;border:1px solid #d8edf6;border-radius:15px;min-height:130px}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media-placeholder{display:flex;position:relative;align-items:center;justify-content:center;flex-direction:column;gap:13px;text-align:center;padding:18px;width:100%;height:100%;min-height:130px;background:radial-gradient(circle at 75% 20%,#d0f2fa,transparent 38%),linear-gradient(145deg,#dff5fb,#edf9fc 45%,#dceefa);color:#31739a;font-size:14px;font-weight:700;overflow:hidden}.placeholder-orbit{border-radius:50%;width:78px;height:78px;border:13px solid rgba(37,182,232,.19);box-shadow:0 0 0 14px rgba(37,200,209,.08);position:relative}.placeholder-orbit:after{content:'';display:block;position:absolute;inset:15px;background:linear-gradient(130deg,#25c8d1,#1787db);border-radius:50%}.hero-media .media-placeholder{min-height:290px}.section-heading{display:flex;align-items:end;justify-content:space-between;gap:20px;margin:0 0 22px}.section-heading h2{margin:0}.text-link{font-size:14px;font-weight:700;color:#117eae}.text-link:hover{text-decoration:underline}.cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.cards.two{grid-template-columns:repeat(2,minmax(0,1fr))}.cards.four{grid-template-columns:repeat(4,minmax(0,1fr))}.card{background:white;border:1px solid var(--line);border-radius:16px;padding:24px;box-shadow:var(--shadow);min-width:0}.card h3{margin:6px 0 10px}.card p{font-size:15px;color:#546f86;margin:0}.card .card-link{margin-top:13px;display:inline-block;color:#087fac;font-weight:700;font-size:14px}.tag{display:inline-block;padding:3px 10px;background:var(--soft);border-radius:999px;color:#1179a8;font-size:12px;font-weight:700;letter-spacing:.02em}.feature-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px;align-items:stretch}.feature-block{padding:30px;border:1px solid var(--line);border-radius:17px;background:#fff}.feature-block h2{font-size:23px}.feature-block .media{height:205px;margin-bottom:19px}.feature-block .media-placeholder{height:100%}.feature-block p{color:#526e86}.strip{display:flex;align-items:center;gap:35px;border-radius:18px;padding:32px 38px;background:linear-gradient(110deg,#173f62,#19608c);color:white}.strip h2,.strip h3{color:white}.strip p{color:#d5ebf7}.strip .main-btn{flex-shrink:0}.article-hero{padding:52px 0 26px;border-bottom:1px solid var(--line);margin-top:0}.article-hero h1{font-size:33px;max-width:850px}.article-hero .lead{margin:0}.article-layout{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:54px;margin-top:38px;align-items:start}.prose{max-width:820px}.prose h2{margin:38px 0 17px}.prose h3{margin:24px 0 12px}.prose p,.prose li{line-height:1.85}.prose ul,.prose ol{padding-left:1.4em}.prose li{margin:7px 0}.prose blockquote{border-left:4px solid var(--cyan);background:var(--soft);border-radius:0 10px 10px 0;padding:20px 24px;margin:23px 0;color:var(--navy)}.side-panel{position:sticky;top:103px;padding:24px;border:1px solid var(--line);border-radius:15px;background:white}.side-panel h2{font-size:18px}.side-panel a{display:block;padding:10px 0;border-bottom:1px solid var(--line);font-size:14px;color:#287097}.side-panel a:last-child{border-bottom:none}.content-media{height:250px;margin:25px 0}.content-media .media-placeholder{min-height:100%}.comparison{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:24px 0}.comparison>div{background:#fff;border:1px solid var(--line);border-radius:14px;padding:24px}.comparison h3{margin-top:0}.info-table{border-collapse:collapse;width:100%;margin:22px 0 30px;background:#fff;font-size:15px}.info-table th,.info-table td{border:1px solid var(--line);padding:12px 16px;text-align:left;vertical-align:top}.info-table th{background:var(--soft);color:var(--ink);font-weight:700}.number-stack{counter-reset:step;display:grid;gap:14px;margin:23px 0}.number-stack>div{counter-increment:step;background:#fff;border:1px solid var(--line);border-radius:12px;padding:17px 20px 17px 65px;position:relative}.number-stack>div:before{content:counter(step,decimal-leading-zero);position:absolute;left:18px;top:14px;font-weight:800;font-size:19px;color:var(--blue)}.number-stack h3{margin:0 0 6px}.number-stack p{margin:0}.related{padding:28px 0;border-top:1px solid var(--line);margin-top:52px}.related-links{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.related-links a{display:flex;justify-content:space-between;gap:12px;background:white;border:1px solid var(--line);border-radius:12px;padding:17px;font-size:14px;font-weight:700;color:var(--navy)}.related-links a:hover{border-color:var(--sky)}.related-links span{color:var(--blue)}.toc-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:17px}.toc-grid>a{background:#fff;padding:20px 23px;border:1px solid var(--line);border-radius:13px}.toc-grid strong{display:block;color:var(--ink);font-size:18px}.toc-grid span{color:#637d92;font-size:14px}.timeline{border-left:3px solid #b9e6f5;padding-left:27px;margin:25px 0}.timeline>div{position:relative;padding:0 0 19px}.timeline>div:before{content:'';width:11px;height:11px;background:var(--sky);border-radius:50%;position:absolute;left:-34px;top:9px}.timeline h3{margin:0 0 7px}.timeline p{margin:0}.faq details{border-bottom:1px solid var(--line);padding:14px 0}.faq summary{font-weight:700;color:var(--ink);cursor:pointer;list-style-position:inside}.faq details p{padding:10px 0 0 19px;margin:0}.site-footer{background:var(--footer);color:#eaf7ff;margin-top:65px;padding-top:50px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:60px}.footer-logo{color:#fff;font-size:23px;font-weight:800}.footer-logo span{font-size:10px;letter-spacing:.12em;margin-left:6px;color:#80d5ef}.footer-grid p{max-width:420px;color:#c5ddeb;font-size:14px;margin-top:14px}.footer-grid .foot-small{color:#a9cada;font-size:12px}.footer-grid h2{color:#fff;font-size:16px;margin:5px 0 14px}.footer-grid div>a:not(.footer-logo){display:block;font-size:14px;padding:5px 0;color:#d0e5ef}.copyright{margin-top:34px;border-top:1px solid rgba(255,255,255,.15);display:flex;justify-content:space-between;padding:19px 0;color:#b7d0df;font-size:12px}@media(max-width:1120px){.header-inner{gap:12px}.desktop-nav a{padding:10px 7px;font-size:13px}.brand-type{font-size:18px}.header-entry{padding:0 14px}}@media(max-width:980px){.header-inner{height:60px;display:grid;grid-template-columns:1fr auto 1fr;gap:10px}.menu-toggle{display:flex;justify-self:start}.desktop-nav{display:none}.brand{justify-self:center}.brand img{height:29px;max-width:145px}.header-entry{justify-self:end;height:40px;font-size:13px;padding:0 14px}.hero{grid-template-columns:1fr;gap:18px;padding:30px}.hero-media{max-width:530px;width:100%;height:215px;margin:auto;order:-1}.hero-media .media-placeholder{min-height:215px}.article-layout{grid-template-columns:1fr;gap:18px}.side-panel{position:static;order:-1}.side-panel a{display:inline-block;border:0;padding:6px 13px 6px 0}.footer-grid{gap:24px}}@media(max-width:660px){body{font-size:15px}.wrap{width:calc(100% - 32px)}h1{font-size:29px}h2{font-size:21px}h3{font-size:18px}.lead{font-size:16px}.hero{margin-top:17px;border-radius:15px;padding:24px 19px}.hero h1{font-size:29px}.hero-media{height:190px}.hero-media .media-placeholder{min-height:190px}.hero .hero-actions{margin-top:18px;gap:10px}.cards,.cards.two,.cards.four,.feature-grid,.comparison,.related-links,.toc-grid{grid-template-columns:1fr}.card{padding:21px}.feature-block{padding:22px}.feature-block .media{height:175px}.strip{flex-direction:column;align-items:flex-start;padding:25px;gap:12px}.article-hero{padding:32px 0 20px}.article-hero h1{font-size:27px}.content-media{height:185px}.info-table{font-size:13px}.info-table th,.info-table td{padding:10px 8px}.section-heading{align-items:start}.footer-grid{grid-template-columns:1fr 1fr;gap:22px}.footer-grid>div:first-child{grid-column:1/-1}.site-footer{margin-top:42px;padding-top:36px;padding-bottom:68px}.copyright{gap:12px;align-items:start;flex-direction:column}.bottom-nav{position:fixed;display:grid;grid-template-columns:repeat(4,1fr);bottom:0;left:0;right:0;z-index:29;background:#fff;border-top:1px solid var(--line);padding:5px 0 max(5px,env(safe-area-inset-bottom));box-shadow:0 -5px 18px rgba(13,73,105,.04)}.bottom-nav a{display:flex;align-items:center;flex-direction:column;gap:0;font-size:11px;line-height:1.3;color:var(--navy);padding:3px}.bottom-nav a span{font-size:21px;color:#158ebc}.brand-type{font-size:16px}.brand-type small{font-size:8px}.brand-symbol{width:34px;height:34px}.header-entry{padding:0 11px;min-width:0}.header-entry span{display:none}section{margin-block:29px}}@media(max-width:350px){.brand-type{font-size:14px}.header-entry{font-size:12px;padding:0 9px}.hero h1{font-size:27px}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition:none!important}}
