:root{--bg:#f5fbff;--white:#fff;--pale:#eaf7fc;--cyan:#25c8d1;--sky:#25b6e8;--blue:#1787db;--navy:#174b78;--dark:#173b60;--ink:#2d4359;--muted:#687f93;--border:#dcebf3;--footer:#123653;--radius:18px;--shadow:0 13px 35px rgba(30,88,135,.07)}
*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:90px}body{margin:0;background:var(--bg);color:var(--ink);font-family:Arial,"PingFang SC","Microsoft YaHei",sans-serif;font-size:16px;line-height:1.8}body.menu-open{overflow:hidden}a{color:inherit;text-decoration:none}a:hover{color:var(--blue)}button{font:inherit}button,a{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--sky);outline-offset:4px}img{max-width:100%}h1,h2,h3,p{margin-top:0}h1,h2,h3{color:var(--dark);line-height:1.38}h1{font-size:clamp(29px,3.25vw,40px);letter-spacing:-.025em}h2{font-size:clamp(21px,2.2vw,26px)}h3{font-size:19px}p{margin-bottom:16px}ul,ol{padding-left:1.4em}li+li{margin-top:6px}.container{max-width:1208px;padding-left:24px;padding-right:24px;margin:auto}.skip-link{position:absolute;left:15px;top:-100px;z-index:100;background:#fff;padding:8px 15px}.skip-link:focus{top:10px}.site-header{position:sticky;top:0;z-index:40;background:#fff;border-bottom:1px solid var(--border);box-shadow:0 2px 16px rgba(32,97,144,.04)}.header-inner{height:72px;display:flex;align-items:center;gap:26px}.brand{display:inline-flex;align-items:center;flex-shrink:0;min-width:0}.brand-logo{display:block;width:auto;height:37px;max-width:190px;object-fit:contain}.brand-word{display:flex;align-items:center;gap:9px;font-size:21px;font-weight:800;color:var(--navy);line-height:1.15;white-space:nowrap}.brand-word small{display:block;letter-spacing:.13em;font-size:9px;margin-top:4px;color:var(--blue)}.brand-ball{display:grid;place-items:center;width:35px;height:35px;background:linear-gradient(120deg,var(--cyan),var(--blue));border-radius:50%;font-size:18px}.desktop-nav{display:flex;align-items:center;gap:21px;margin-left:auto;white-space:nowrap}.desktop-nav a{font-size:14px;font-weight:700;color:var(--dark);border-bottom:3px solid transparent;padding:24px 0 20px}.desktop-nav a:hover,.desktop-nav a.is-active{color:var(--blue);border-bottom-color: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;text-decoration:none;white-space:nowrap;box-shadow:0 7px 16px rgba(37,182,232,.18)}.main-btn:hover{color:#fff;filter:brightness(.94)}.header-action{margin-left:4px;font-size:14px}.menu-toggle{display:none;border:0;background:transparent;padding:10px;cursor:pointer;width:42px;height:42px;flex-direction:column;justify-content:space-around}.menu-toggle span{display:block;background:var(--navy);width:22px;height:2px;border-radius:2px}.drawer-overlay{position:fixed;inset:0;background:rgba(10,42,70,.48);z-index:50;opacity:0;visibility:hidden;pointer-events:none;transition:opacity .25s,visibility .25s}.drawer-overlay.is-open{opacity:1;visibility:visible;pointer-events:auto}.drawer{position:fixed;top:0;left:0;bottom:0;z-index:60;width:min(86vw,340px);background:#fff;transform:translateX(-103%);visibility:hidden;transition:transform .25s,visibility .25s;overflow:auto;box-shadow:18px 0 35px rgba(0,0,0,.13)}.drawer.is-open{transform:translateX(0);visibility:visible}.drawer-head{height:75px;display:flex;align-items:center;justify-content:space-between;padding:15px 20px;border-bottom:1px solid var(--border)}.drawer-close{border:0;background:var(--pale);color:var(--dark);width:39px;height:39px;border-radius:10px;cursor:pointer;font-size:27px;line-height:1}.drawer-content{padding:8px 20px 35px}.drawer-content a{display:block;padding:8px 10px;border-radius:9px;font-size:15px}.drawer-content a:hover{background:var(--pale)}.drawer-label{font-size:12px;letter-spacing:.12em;font-weight:700;color:var(--blue);margin:24px 0 4px;padding-left:10px}.hero{padding:56px 0 42px}.hero-layout{display:grid;grid-template-columns:1.06fr .94fr;align-items:center;gap:45px}.eyebrow{display:inline-block;font-size:12px;font-weight:800;letter-spacing:.14em;color:var(--blue);text-transform:uppercase;margin-bottom:12px}.hero h1{margin-bottom:20px}.lead{font-size:17px;line-height:1.85;color:#47637b}.hero-cta{display:flex;align-items:center;gap:18px;margin-top:26px;flex-wrap:wrap}.text-link{color:var(--blue);font-weight:700}.hero-note{font-size:13px;color:var(--muted);margin-top:18px}.media{display:flex;align-items:center;justify-content:center;width:100%;background:var(--pale);border-radius:14px;overflow:hidden;min-height:160px}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media--fallback{flex-direction:column;gap:11px;color:#507b9d;text-align:center;font-size:14px;line-height:1.4;padding:25px;background:linear-gradient(125deg,#e5f8fb,#d5edf9);border:1px solid var(--border)}.fallback-mark{width:55px;height:55px;border:2px solid #a8dce9;border-radius:15px;position:relative;transform:rotate(-6deg)}.fallback-mark:before{content:'';position:absolute;left:12px;top:12px;width:12px;height:12px;border-radius:50%;background:#8bc7d8}.fallback-mark:after{content:'';position:absolute;width:28px;height:23px;left:12px;bottom:7px;border-left:3px solid #8bc7d8;border-bottom:3px solid #8bc7d8;transform:skewX(-24deg) rotate(-15deg)}.hero-media{height:330px;box-shadow:var(--shadow)}.hero-media img{max-height:100%}.section{padding:42px 0}.section--white{background:#fff}.section--soft{background:var(--pale)}.section-top{display:flex;justify-content:space-between;align-items:end;gap:24px;margin-bottom:24px}.section-top h2{margin-bottom:4px}.section-intro{max-width:730px;color:var(--muted)}.cards-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.cards-2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}.card{background:white;border:1px solid var(--border);border-radius:var(--radius);padding:25px;box-shadow:var(--shadow)}.card h3{margin-bottom:10px}.card p{color:#506b80;margin-bottom:12px}.card .more{font-size:14px;font-weight:700;color:var(--blue)}.card-kicker{font-size:12px;letter-spacing:.11em;color:var(--blue);font-weight:800;margin-bottom:11px}.section-index{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.section-index a{padding:21px 22px;background:#fff;border:1px solid var(--border);border-radius:14px;min-height:110px;display:flex;flex-direction:column;justify-content:space-between;transition:transform .2s,border-color .2s}.section-index a:hover{transform:translateY(-3px);border-color:var(--sky)}.section-index strong{color:var(--dark);font-size:18px}.section-index span{font-size:13px;color:var(--muted)}.split{display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:center}.split--narrow{grid-template-columns:1.2fr .8fr}.text-panel{background:#fff;border:1px solid var(--border);padding:26px;border-radius:var(--radius)}.feature-media{height:238px}.feature-media img{max-height:100%}.mini-list{list-style:none;padding:0;margin:0}.mini-list li{margin:0;border-bottom:1px solid var(--border);padding:12px 0}.mini-list a{display:flex;justify-content:space-between;font-weight:700;color:var(--dark)}.mini-list a:after{content:'↗';color:var(--blue)}.pill{display:inline-block;background:#dff5fb;color:#136b88;border-radius:999px;padding:4px 12px;font-size:12px;font-weight:700}.article-shell{padding:45px 0 62px}.page-intro{max-width:845px;margin-bottom:38px}.page-intro h1{font-size:clamp(27px,3vw,34px);margin:7px 0 16px}.page-intro .lead{margin-bottom:12px}.article-width{max-width:820px}.reading-section{margin-bottom:40px}.reading-section h2{border-left:4px solid var(--cyan);padding-left:15px;margin:0 0 16px}.reading-section h3{margin:25px 0 9px}.article-media{height:245px;margin:22px 0 27px}.article-media img{max-height:100%}.quote-strip{background:linear-gradient(100deg,#e3f9fb,#edf5ff);padding:22px 26px;border-left:4px solid var(--cyan);border-radius:0 14px 14px 0;margin:25px 0;font-size:17px;color:var(--dark)}.comparison-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:20px 0}.comparison-grid>div{background:#fff;border:1px solid var(--border);border-radius:15px;padding:23px}.comparison-grid h3{margin-top:0}.data-table{border-collapse:collapse;width:100%;background:white;border:1px solid var(--border);font-size:15px;margin:18px 0 27px}.data-table th,.data-table td{padding:13px 15px;border:1px solid var(--border);text-align:left;vertical-align:top}.data-table th{background:#dff5fb;color:var(--dark)}.number-steps{counter-reset:steps;list-style:none;padding:0}.number-steps li{position:relative;padding:0 0 20px 53px;margin:0 0 15px;border-bottom:1px solid var(--border)}.number-steps li:before{counter-increment:steps;content:counter(steps,decimal-leading-zero);position:absolute;left:0;top:0;color:var(--blue);font-weight:800;font-size:20px}.timeline{border-left:2px solid #b1e2ec;padding-left:22px;margin-left:9px}.timeline>div{position:relative;margin-bottom:30px}.timeline>div:before{content:'';width:12px;height:12px;position:absolute;left:-29px;top:8px;border-radius:50%;background:var(--cyan);border:2px solid white}.timeline h3{margin-bottom:5px}.topic-line{display:grid;grid-template-columns:160px 1fr;gap:24px;border-top:1px solid var(--border);padding:22px 0}.topic-line h3{margin:0}.topic-line p{margin:0}.gallery-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.gallery-item{border:1px solid var(--border);background:#fff;border-radius:16px;padding:16px}.gallery-item .media{height:192px;margin-bottom:15px}.gallery-item p{font-size:14px;color:var(--muted);margin:0}.gallery-item h3{margin:0 0 6px}.related{margin-top:44px;border-top:1px solid var(--border);padding-top:25px}.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.related-grid a{background:white;border:1px solid var(--border);border-radius:12px;padding:15px 17px;font-weight:700;font-size:14px;color:var(--dark);display:flex;justify-content:space-between;gap:10px}.related-grid a span{color:var(--blue)}.faq details{background:white;border:1px solid var(--border);border-radius:12px;margin:9px 0;padding:14px 18px}.faq summary{cursor:pointer;color:var(--dark);font-weight:700}.faq details p{margin:10px 0 0}.site-footer{background:var(--footer);color:#eaf7ff;padding:48px 0 22px}.footer-grid{display:grid;grid-template-columns:1.1fr .7fr 1fr;gap:45px}.footer-brand{margin-bottom:15px}.site-footer .brand-word,.site-footer h2{color:#fff}.site-footer .brand-word small{color:#b6eafb}.site-footer p{font-size:14px;color:#c6dfef}.site-footer h2{font-size:17px;margin-bottom:14px}.footer-links{display:grid;grid-template-columns:1fr 1fr;gap:9px}.footer-links a,.footer-more{color:#eaf7ff;font-size:14px}.footer-bottom{display:flex;justify-content:space-between;gap:15px;border-top:1px solid rgba(255,255,255,.16);padding-top:20px;margin-top:35px;font-size:12px;color:#b5d0df}.back-top{position:fixed;right:23px;bottom:25px;border:0;border-radius:50%;width:42px;height:42px;background:var(--blue);color:#fff;cursor:pointer;box-shadow:var(--shadow);z-index:30;opacity:0;visibility:hidden;transform:translateY(8px);transition:.2s}.back-top.is-visible{opacity:1;visibility:visible;transform:translateY(0)}.mobile-bottom{display:none}.label-row{display:flex;gap:10px;flex-wrap:wrap;margin:16px 0}.note{font-size:14px;color:var(--muted)}
@media(max-width:1100px){.desktop-nav{gap:12px}.desktop-nav a{font-size:13px}.header-inner{gap:14px}.brand-word{font-size:19px}}
@media(max-width:980px){.desktop-nav{display:none}.menu-toggle{display:flex;margin-left:-10px}.header-inner{height:60px;justify-content:space-between;gap:8px}.header-inner>.brand{position:absolute;left:50%;transform:translateX(-50%)}.brand-logo{height:29px;max-width:145px}.brand-word{font-size:16px;gap:5px}.brand-word small{font-size:7px}.brand-ball{width:27px;height:27px;font-size:14px}.header-action{height:39px;font-size:12px;padding:0 13px;margin-left:auto}.footer-grid{grid-template-columns:1fr 1fr}.footer-grid>div:last-child{grid-column:1/-1}.hero-layout{gap:20px}}
@media(max-width:700px){body{font-size:15px}.container{padding-left:16px;padding-right:16px}.hero{padding:27px 0 25px}.hero-layout,.split,.split--narrow{grid-template-columns:1fr}.hero-layout .hero-media{grid-row:1}.hero h1{font-size:29px}.hero-media{height:195px}.lead{font-size:15px}.section{padding:30px 0}.section-top{display:block}.section-intro{font-size:14px}.cards-3,.cards-2,.section-index,.gallery-grid,.comparison-grid,.related-grid{grid-template-columns:1fr}.card{padding:21px}.section-index{gap:11px}.section-index a{min-height:89px;padding:15px 18px}.feature-media{height:190px}.article-shell{padding:28px 0 44px}.page-intro h1{font-size:27px}.reading-section{margin-bottom:33px}.reading-section h2{font-size:21px}.reading-section h3{font-size:17px}.article-media{height:185px}.topic-line{grid-template-columns:1fr;gap:8px;padding:18px 0}.data-table{font-size:13px}.data-table th,.data-table td{padding:10px 8px}.gallery-item .media{height:168px}.footer-grid{grid-template-columns:1fr;gap:20px}.footer-grid>div:last-child{grid-column:auto}.footer-bottom{display:block}.site-footer{padding:35px 0 94px}.mobile-bottom{position:fixed;bottom:0;left:0;right:0;z-index:35;background:white;display:grid;grid-template-columns:repeat(4,1fr);border-top:1px solid var(--border);padding-bottom:env(safe-area-inset-bottom);box-shadow:0 -5px 25px rgba(25,68,97,.07)}.mobile-bottom a{padding:9px 4px;text-align:center;font-size:12px;font-weight:700;color:var(--muted)}.mobile-bottom a.is-active{color:var(--blue)}.back-top{bottom:70px;right:16px}.hero-cta{gap:14px}}
@media(max-width:360px){.header-action{padding:0 9px;min-width:70px}.brand-word{font-size:14px}.brand-ball{width:24px;height:24px}.header-inner{gap:4px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}}