:root{--bg:#f5fbff;--white:#fff;--soft:#eaf7fc;--cyan:#25c8d1;--sky:#25b6e8;--blue:#1787db;--navy:#174b78;--ink:#173b60;--body:#2d4359;--muted:#687f93;--line:#dcebf3;--footer:#123653;--radius:19px;--shadow:0 13px 38px rgba(23,75,120,.07)}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:90px}body{margin:0;color:var(--body);background:var(--bg);font:16px/1.8 Arial,'PingFang SC','Microsoft YaHei',sans-serif}body.menu-open{overflow:hidden}a{color:var(--blue);text-decoration:none}a:hover{color:#0d699f}button{font:inherit;cursor:pointer}img{max-width:100%}h1,h2,h3,h4{color:var(--ink);line-height:1.38;margin:0 0 .68em;letter-spacing:-.025em}h1{font-size:clamp(27px,3.6vw,40px)}h2{font-size:clamp(20px,2.3vw,26px)}h3{font-size:clamp(17px,1.85vw,20px)}p{margin:0 0 1.15em}.wrap{width:min(1160px,calc(100% - 48px));margin:0 auto}.skip-link{position:absolute;left:12px;top:-70px;background:#fff;z-index:9999;padding:10px}.skip-link:focus{top:10px}.site-header{position:sticky;top:0;z-index:100;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 5px 25px rgba(23,75,120,.035)}.header-inner{height:72px;display:flex;align-items:center;gap:22px}.brand{flex:0 0 auto;display:flex;align-items:center;min-width:148px}.brand img{width:auto;height:auto;max-height:38px;object-fit:contain}.brand-fallback{display:flex;flex-direction:column;line-height:1.2;color:var(--navy)}.brand-fallback b{font-size:22px;letter-spacing:.08em}.brand-fallback small{letter-spacing:.17em;font-size:8px}.desktop-nav{margin-left:auto;display:flex;align-items:center;gap:clamp(10px,1.4vw,21px)}.desktop-nav a{font-size:14px;font-weight:650;color:var(--navy);white-space:nowrap;position:relative}.desktop-nav a:hover,.desktop-nav [aria-current=page]{color:#1597bf}.desktop-nav [aria-current=page]:after{content:"";position:absolute;bottom:-23px;left:0;right:0;height:3px;border-radius:5px;background:var(--cyan)}.main-btn{display:inline-flex;align-items:center;justify-content:center;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 7px 17px rgba(37,182,232,.2)}.main-btn:hover{color:#fff;filter:brightness(.96);transform:translateY(-1px)}.header-cta{margin-left:8px;font-size:14px}.menu-toggle{display:none;border:0;background:transparent;width:42px;height:42px;padding:12px;align-items:center;flex-direction:column;justify-content:center;gap:5px}.menu-toggle span{height:2px;width:22px;background:var(--navy);display:block;border-radius:2px}.drawer{position:fixed;z-index:210;inset:0 auto 0 0;width:min(86vw,340px);background:white;box-shadow:18px 0 50px rgba(15,48,80,.1);transform:translateX(-105%);visibility:hidden;transition:transform .24s,visibility .24s;overflow-y:auto;padding:21px 22px 35px}.drawer-backdrop{position:fixed;inset:0;background:rgba(15,46,78,.5);z-index:200;opacity:0;visibility:hidden;pointer-events:none;transition:opacity .24s,visibility .24s}.menu-open .drawer{transform:none;visibility:visible}.menu-open .drawer-backdrop{opacity:1;visibility:visible;pointer-events:auto}.drawer-top{display:flex;align-items:center;justify-content:space-between;font-weight:700;color:var(--ink)}.drawer-close{border:0;background:var(--soft);color:var(--ink);border-radius:50%;height:37px;width:37px;font-size:25px;line-height:1}.drawer-brand{margin:16px 0}.drawer-brand img{max-height:43px;width:auto;object-fit:contain}.drawer-group{font-size:12px;font-weight:700;color:#7492a6;margin:24px 0 5px;letter-spacing:.12em}.drawer nav a{display:block;padding:10px 8px;border-bottom:1px solid var(--line);color:var(--ink);font-weight:600}.section{padding:44px 0}.section-head{max-width:700px;margin-bottom:26px}.section-head p{color:var(--muted)}.eyebrow,.kicker{display:inline-block;color:#008fa7;font-size:12px;font-weight:800;letter-spacing:.14em;text-transform:uppercase;margin-bottom:11px}.hero{padding:48px 0 33px}.hero-layout{display:grid;grid-template-columns:1.06fr .94fr;gap:35px;align-items:center}.hero-copy{padding:14px 0}.hero-copy p{font-size:17px;max-width:550px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:24px}.outline-btn{display:inline-flex;align-items:center;padding:7px 21px;min-height:42px;border:1px solid #b6ddea;border-radius:100px;font-weight:700;background:#fff}.media{margin:0;display:flex;justify-content:center;align-items:center;overflow:hidden;border-radius:16px;background:linear-gradient(145deg,#eaf7fc,#dff5fb);position:relative}.media--hero{aspect-ratio:1.55}.media--landscape{aspect-ratio:1.8}.media--banner{aspect-ratio:3.3}.media--portrait{aspect-ratio: .78;max-width:340px}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media-art{width:100%;height:100%;position:absolute;inset:0;background:radial-gradient(circle at 83% 30%,rgba(255,255,255,.9),transparent 32%),linear-gradient(130deg,#dff5fb,#b9e9f2 48%,#a7d6f5);overflow:hidden}.media-art:after{content:"";position:absolute;width:65%;height:65%;left:19%;top:12%;border:1px solid rgba(255,255,255,.7);border-radius:50%;transform:rotate(-18deg)}.orb{position:absolute;display:block;border-radius:50%;filter:blur(1px)}.orb-a{width:42%;aspect-ratio:1;left:38%;top:5%;background:linear-gradient(150deg,#21bee0,#1888c9);opacity:.5;box-shadow:30px 30px 55px rgba(12,106,164,.2)}.orb-b{width:25%;aspect-ratio:1;left:7%;bottom:-4%;background:linear-gradient(130deg,#8be2de,#4cb2f0);opacity:.75}.art-line{position:absolute;left:-12%;right:-12%;top:62%;transform:rotate(-19deg);border-top:2px solid rgba(255,255,255,.75);box-shadow:0 14px 0 rgba(255,255,255,.25)}.section-band{background:#eaf7fc}.topic-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.topic-card,.paper-card,.quote-card,.metric,.faq-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow)}.topic-card{display:block;color:var(--body);min-height:172px;transition:transform .18s}.topic-card:hover{transform:translateY(-3px);color:var(--body);border-color:#a8dce7}.topic-card span{color:#009fae;font-size:12px;font-weight:800}.topic-card h3{margin:12px 0 6px}.topic-card p{font-size:14px;color:var(--muted);margin:0}.topic-card em{font-style:normal;color:#168ac0;font-weight:700}.feature-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:26px;align-items:center}.feature-grid.flip{grid-template-columns:.9fr 1.1fr}.feature-copy{max-width:660px}.feature-copy h2{margin-bottom:12px}.pills{display:flex;flex-wrap:wrap;gap:8px}.pills span{border:1px solid #c5e7ef;background:white;padding:3px 12px;border-radius:100px;color:var(--navy);font-size:13px;font-weight:700}.article-index{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px}.article-index a{display:block;border-bottom:1px solid #cfe2ee;padding:18px 0;color:var(--ink);font-weight:700}.article-index a:after{content:'↗';float:right;color:var(--sky)}.page-head{padding:50px 0 25px}.page-head .intro{max-width:780px;font-size:17px;color:#587187}.page-tag{font-size:12px;color:#009fab;font-weight:800;letter-spacing:.15em}.reading-layout{display:grid;grid-template-columns:minmax(0,800px) minmax(190px,1fr);align-items:start;gap:36px}.prose{max-width:820px}.prose p{line-height:1.82}.prose h2{margin-top:31px}.prose h3{margin-top:22px}.prose ul,.prose ol{padding-left:23px}.prose li{margin:7px 0}.aside-box{position:sticky;top:105px;background:#fff;border:1px solid var(--line);border-radius:16px;padding:20px}.aside-box a{display:block;padding:9px 0;border-bottom:1px solid var(--line);font-size:14px}.aside-box a:last-child{border:0}.split-two,.compare-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.compare-grid .paper-card{padding:25px}.number-list{counter-reset:steps;display:grid;gap:13px}.number-list .step{background:white;border:1px solid var(--line);border-radius:15px;padding:17px 20px 17px 64px;position:relative}.step:before{counter-increment:steps;content:counter(steps,decimal-leading-zero);position:absolute;left:17px;top:15px;color:#0797b0;font-weight:800}.table-wrap{overflow-x:auto;margin:21px 0}table{border-collapse:collapse;width:100%;background:white;border:1px solid var(--line);border-radius:12px;overflow:hidden}th,td{text-align:left;border-bottom:1px solid var(--line);padding:12px 15px;vertical-align:top}th{color:var(--ink);background:#eaf7fc}.related{margin:30px 0 18px;border-top:1px solid #cbe3ec;padding-top:22px}.related strong{display:block;color:var(--ink);margin-bottom:13px}.related>div{display:flex;gap:10px;flex-wrap:wrap}.related a{background:white;border:1px solid var(--line);border-radius:11px;padding:9px 13px;color:var(--navy);font-size:14px}.related a span{padding-left:13px;color:var(--sky)}.note{padding:17px 20px;border-left:3px solid var(--cyan);background:#eaf7fc;border-radius:0 12px 12px 0}.wide-banner{padding:26px;background:linear-gradient(110deg,#174b78,#1787db);color:white;border-radius:20px}.wide-banner h2,.wide-banner h3{color:#fff}.wide-banner p{color:#e5f8ff}.visual-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.visual-grid article{border:1px solid var(--line);border-radius:17px;background:white;overflow:hidden}.visual-grid article>div{padding:16px 18px}.visual-grid h3{margin-bottom:7px}.visual-grid p{font-size:14px;color:var(--muted);margin:0}.visual-grid .media{border-radius:0}.service-list{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.service-list>div{background:#fff;border:1px solid var(--line);padding:22px;border-radius:15px}.faq-list details{border-bottom:1px solid #c9e2ed;padding:17px 0}.faq-list summary{cursor:pointer;font-weight:700;color:var(--ink)}.faq-list p{margin:10px 0 0}.site-footer{background:var(--footer);color:#eaf7ff;margin-top:44px;padding:43px 0 20px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:45px}.footer-grid strong{display:block;color:white;margin-bottom:12px}.footer-grid nav a{display:block;color:#eaf7ff;font-size:14px;margin:7px 0}.footer-grid p{color:#d5ebf7;font-size:14px}.footer-note{max-width:400px}.footer-brand img{height:auto;max-height:42px;object-fit:contain}.footer-bottom{border-top:1px solid rgba(255,255,255,.17);display:flex;justify-content:space-between;gap:15px;margin-top:24px;padding-top:16px;color:#b8d5e9;font-size:12px}.mobile-bottom{display:none}.back-top{position:fixed;right:20px;bottom:25px;width:42px;height:42px;border:0;border-radius:50%;background:var(--navy);color:white;opacity:0;pointer-events:none;transition:opacity .2s;z-index:90;box-shadow:0 4px 15px #12365335}.back-top.visible{opacity:1;pointer-events:auto}
@media(max-width:1090px){.desktop-nav{gap:10px}.desktop-nav a{font-size:13px}.brand{min-width:130px}.header-inner{gap:13px}.header-cta{padding:0 13px}}
@media(max-width:980px){.menu-toggle{display:flex}.desktop-nav{display:none}.header-inner{justify-content:space-between;height:60px}.brand{margin:auto;justify-content:center;min-width:0}.brand img{max-height:30px;max-width:145px}.header-cta{margin:0;font-size:13px;height:39px;padding:0 13px}.hero-layout{grid-template-columns:1fr 1fr}.reading-layout{grid-template-columns:minmax(0,1fr)}.aside-box{position:static}.footer-grid{gap:25px}}
@media(max-width:650px){body{font-size:15px}.wrap{width:calc(100% - 32px)}.header-inner{gap:6px}.hero{padding:24px 0}.hero-layout{display:flex;flex-direction:column;gap:20px}.hero-layout>.media{order:-1;width:100%}.hero-copy{padding:0}.hero-copy p,.page-head .intro{font-size:15px}.section{padding:29px 0}.section-head{margin-bottom:18px}.page-head{padding:29px 0 13px}.topic-grid,.visual-grid,.service-list{grid-template-columns:1fr 1fr;gap:12px}.topic-card{min-height:0;padding:16px}.topic-card h3{font-size:17px}.feature-grid,.feature-grid.flip,.split-two,.compare-grid,.article-index{grid-template-columns:1fr;gap:17px}.feature-grid .media{max-height:220px}.media--hero{aspect-ratio:1.85}.media--banner{aspect-ratio:2.1}.media--portrait{max-width:220px;margin:auto}.footer-grid{grid-template-columns:1fr 1fr;gap:21px}.footer-grid>div{grid-column:1/-1}.footer-bottom{display:block}.site-footer{padding-bottom:84px}.mobile-bottom{display:grid;grid-template-columns:repeat(4,1fr);position:fixed;bottom:0;left:0;right:0;z-index:120;height:57px;background:white;border-top:1px solid var(--line);box-shadow:0 -3px 18px #173b6012}.mobile-bottom a{display:flex;align-items:center;justify-content:center;font-size:13px;color:var(--navy);font-weight:700}.mobile-bottom [aria-current=page]{color:#0098ba}.back-top{bottom:70px;right:15px}.site-header .brand-fallback b{font-size:17px}.site-header .brand-fallback small{font-size:7px}}
@media(max-width:390px){.topic-grid,.visual-grid,.service-list{grid-template-columns:1fr}.header-cta{font-size:12px;padding:0 10px;min-width:72px}.brand img{max-width:120px}.menu-toggle{width:38px}.article-index a{padding:11px 0}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}
