:root{--bg:#f5fbff;--white:#fff;--soft:#eaf7fc;--pale:#dff5fb;--cyan:#25c8d1;--sky:#25b6e8;--blue:#1787db;--ocean:#174b78;--title:#173b60;--text:#2d4359;--muted:#687f93;--border:#dcebf3;--footer:#123653;--shadow:0 16px 48px rgba(19,75,120,.07)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);font-family:Arial,'PingFang SC','Microsoft YaHei',sans-serif;color:var(--text);font-size:16px;line-height:1.8}a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--cyan);outline-offset:3px}img{max-width:100%}.shell{width:min(1160px,calc(100% - 48px));margin:0 auto}.skip-link{position:absolute;left:12px;top:-90px;padding:8px 12px;background:white;z-index:100}.skip-link:focus{top:12px}.site-header{background:#fff;border-bottom:1px solid var(--border);position:relative;z-index:20}.header-inner{display:flex;align-items:center;justify-content:space-between;min-height:72px;gap:18px}.brand,.footer-brand{display:inline-flex;align-items:center;flex-shrink:0}.brand-logo{max-width:165px;max-height:38px;width:auto;height:auto;object-fit:contain}.brand-fallback{font-weight:900;white-space:nowrap;color:var(--ocean);font-size:24px;letter-spacing:1px}.brand-fallback span{color:var(--sky)}.desktop-nav{display:flex;align-items:center;gap:clamp(12px,1.5vw,23px)}.desktop-nav a{white-space:nowrap;font-size:14px;font-weight:650;color:var(--ocean);padding:24px 0 22px;border-bottom:3px solid transparent}.desktop-nav a:hover,.desktop-nav .active{color:var(--blue);border-bottom-color:var(--cyan);text-decoration:none}.main-btn{display:inline-flex;justify-content:center;align-items:center;min-width:82px;height:42px;padding:0 20px;border-radius:999px;background:linear-gradient(110deg,#25c8d1,#25b6e8,#1787db);color:#fff;font-weight:700;font-size:14px;text-decoration:none;white-space:nowrap}.main-btn:hover{color:#fff;text-decoration:none;filter:brightness(.96)}.mobile-menu{display:none}.main-content{padding:36px 0 70px;min-height:65vh}h1,h2,h3{color:var(--title);line-height:1.38}h1{font-size:34px;margin:0 0 20px}h2{font-size:25px;margin:0 0 17px}h3{font-size:19px;margin:0 0 10px}p{margin:0 0 17px}.eyebrow{color:#087baf;font-size:13px;text-transform:uppercase;letter-spacing:.15em;font-weight:800;margin-bottom:13px}.lead{font-size:17px;line-height:1.85;color:#476178}.hero{display:grid;grid-template-columns:1.05fr .95fr;align-items:center;gap:40px;padding:40px 46px;background:linear-gradient(115deg,#fff 42%,#e7f9fd);border:1px solid var(--border);border-radius:22px;box-shadow:var(--shadow)}.hero h1{font-size:39px;letter-spacing:-.02em}.hero .lead{max-width:550px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:23px}.secondary-btn{display:inline-flex;align-items:center;padding:7px 20px;border:1px solid #b5dfe9;border-radius:99px;font-weight:700;color:var(--ocean)}.media{display:flex;justify-content:center;align-items:center;width:100%;overflow:hidden;background:var(--soft);border-radius:12px;min-height:160px}.media img{display:block;width:auto;height:auto;max-width:100%;max-height:100%;object-fit:contain;object-position:center}.media--placeholder{background:linear-gradient(145deg,#eaf7fc,#dff5fb);border:1px solid #cde9ef}.placeholder-mark{display:block;width:29%;aspect-ratio:1;border:2px solid #b3dae8;border-radius:50%;position:relative;opacity:.65}.placeholder-mark:after{content:'';position:absolute;width:65%;height:2px;background:#b3dae8;transform:rotate(-42deg);top:50%;left:17%}.hero-media{height:300px}.hero-media img{max-height:300px}.content-section{margin-top:42px}.section-heading{display:flex;justify-content:space-between;align-items:baseline;gap:18px;margin-bottom:16px}.section-heading h2{margin:0}.section-heading a{font-size:14px;white-space:nowrap}.topic-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.topic-card{background:#fff;border:1px solid var(--border);border-radius:16px;padding:24px;transition:transform .2s,box-shadow .2s}.topic-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);text-decoration:none}.topic-card .tag{display:inline-block;color:#1687ad;font-size:12px;font-weight:800;letter-spacing:.08em;margin-bottom:10px}.topic-card h3{margin:0 0 9px}.topic-card p{font-size:14px;color:var(--muted);line-height:1.8;margin:0}.split-feature{display:grid;grid-template-columns:1fr 1fr;gap:26px;background:#fff;border:1px solid var(--border);border-radius:18px;padding:26px;align-items:center}.split-feature.reverse .media{order:-1}.feature-media{height:245px}.feature-media img{max-height:245px}.plain-link{font-weight:700}.article-directory{display:grid;grid-template-columns:repeat(2,1fr);gap:13px}.directory-item{display:block;background:#fff;border:1px solid var(--border);border-radius:12px;padding:17px 20px;color:var(--title)}.directory-item span{display:block;font-size:12px;color:#1685a8;font-weight:700}.directory-item strong{display:block;font-size:17px;margin:5px 0}.directory-item small{font-size:13px;color:var(--muted)}.notice-banner{background:#e5f5fa;border-left:4px solid var(--cyan);padding:20px 24px;border-radius:0 12px 12px 0;margin-top:30px}.page-head{max-width:880px;padding:22px 0 16px}.page-head h1{margin-bottom:15px}.page-layout{display:grid;grid-template-columns:minmax(0,820px) minmax(190px,1fr);align-items:start;gap:38px}.article{max-width:820px}.article-section{padding:28px 0;border-top:1px solid var(--border)}.article-section:first-child{border-top:0}.article-section p{line-height:1.84}.aside-nav{position:sticky;top:20px;background:#fff;padding:22px;border:1px solid var(--border);border-radius:14px}.aside-nav h2{font-size:17px}.aside-nav a{display:block;color:var(--ocean);font-size:14px;padding:7px 0;border-top:1px solid #edf5f8}.aside-nav a:hover{color:var(--blue)}.inline-media{height:245px;margin:20px 0 25px}.inline-media img{max-height:245px}.quote-feature{padding:24px 28px;background:#fff;border-left:4px solid var(--sky);font-size:18px;color:var(--title);margin:22px 0}.compare-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;margin:22px 0}.compare-card{background:#fff;border:1px solid var(--border);border-radius:14px;padding:23px}.compare-card h3{margin-top:0}.compare-card ul{padding-left:22px;margin:0}.key-points{padding-left:24px}.key-points li{padding:5px 0}.table-scroll{overflow-x:auto;margin:24px 0}.info-table{width:100%;border-collapse:collapse;min-width:520px;background:#fff}.info-table th,.info-table td{text-align:left;border:1px solid var(--border);padding:13px 16px;vertical-align:top}.info-table th{background:#eaf7fc;color:var(--title)}.timeline{counter-reset:steps;list-style:none;padding:0}.timeline li{position:relative;padding:3px 0 20px 60px;margin-bottom:12px;border-bottom:1px solid var(--border)}.timeline li:before{counter-increment:steps;content:counter(steps,decimal-leading-zero);position:absolute;left:0;top:0;display:grid;place-items:center;width:42px;height:42px;background:var(--pale);border-radius:12px;color:var(--ocean);font-weight:800}.visual-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:20px}.visual-card{background:#fff;border-radius:15px;border:1px solid var(--border);padding:16px}.visual-card .media{height:215px}.visual-card .media img{max-height:215px}.visual-card h3{margin:14px 4px 8px}.visual-card p{padding:0 4px;font-size:14px;color:var(--muted)}.faq details{padding:17px 20px;background:#fff;border:1px solid var(--border);border-radius:10px;margin:10px 0}.faq summary{font-weight:700;color:var(--title);cursor:pointer}.faq details p{margin:12px 0 0}.related-section{margin-top:40px;padding-top:28px;border-top:1px solid var(--border)}.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.related-link{display:flex;justify-content:space-between;gap:12px;background:#fff;border:1px solid var(--border);border-radius:12px;padding:16px 18px;font-weight:700;color:var(--ocean)}.related-link:hover{text-decoration:none;border-color:var(--sky)}.site-footer{background:var(--footer);color:#eaf7ff}.footer-main{display:grid;grid-template-columns:1.1fr 1fr 1.1fr;gap:55px;padding-top:45px;padding-bottom:38px}.site-footer h2{color:#fff;font-size:17px}.footer-about p,.footer-notice p{font-size:14px;color:#c6d9e8}.footer-links nav{display:grid;grid-template-columns:1fr 1fr;gap:6px 12px}.site-footer a{color:#d6f3ff;font-size:14px}.site-footer .brand-fallback{color:#fff}.footer-bottom{display:flex;justify-content:space-between;gap:10px;border-top:1px solid #3e627b;padding:15px 0;font-size:12px;color:#c8dfed}.bottom-nav{display:none}.top-button{position:fixed;right:20px;bottom:20px;border:0;background:var(--blue);color:#fff;width:42px;height:42px;border-radius:50%;font-size:22px;cursor:pointer;opacity:0;pointer-events:none;transition:opacity .2s;z-index:5}.top-button.visible{opacity:1;pointer-events:auto}
@media(max-width:1100px){.desktop-nav{gap:10px}.desktop-nav a{font-size:13px}.brand-logo{max-width:135px}.header-inner{gap:12px}}
@media(max-width:980px){.desktop-nav{display:none}.mobile-menu{display:block;order:0}.brand{order:1;margin:0 auto}.header-entry{order:2}.header-inner{height:60px;min-height:60px}.brand-logo{max-height:30px}.mobile-menu summary{display:grid;place-items:center;width:40px;height:40px;cursor:pointer;list-style:none;border-radius:8px}.mobile-menu summary::-webkit-details-marker{display:none}.hamburger{display:grid;gap:5px}.hamburger i{height:2px;width:21px;background:var(--ocean);display:block}.mobile-panel{position:absolute;left:0;top:100%;width:min(86vw,340px);max-height:calc(100vh - 60px);overflow:auto;background:white;padding:22px;box-shadow:14px 20px 45px rgba(8,40,75,.18);border:1px solid var(--border);z-index:22}.drawer-brand{margin-bottom:6px}.drawer-caption{font-size:13px;color:var(--muted)}.drawer-group{display:block;font-size:12px;font-weight:800;letter-spacing:.08em;color:#188ba4;margin-top:19px}.mobile-panel nav a{display:block;color:var(--title);padding:9px 0;border-bottom:1px solid var(--border)}.page-layout{grid-template-columns:1fr}.aside-nav{position:static;order:-1}.aside-nav a{display:inline-block;padding:8px 10px;border:0}.footer-main{gap:24px}}
@media(max-width:700px){body{font-size:15px}.shell{width:calc(100% - 32px)}.main-content{padding:20px 0 68px}.hero{padding:23px;grid-template-columns:1fr;gap:20px}.hero .hero-media{order:-1;height:195px}.hero-media img{max-height:195px}.hero h1{font-size:29px}.lead{font-size:15px}.page-head h1{font-size:27px}.page-head{padding:15px 0}.topic-grid,.article-directory,.visual-grid,.compare-grid,.related-grid{grid-template-columns:1fr}.topic-card{padding:19px}.split-feature{grid-template-columns:1fr;padding:18px;gap:15px}.split-feature .media{order:-1}.feature-media{height:180px}.feature-media img{max-height:180px}.content-section{margin-top:30px}.section-heading h2,h2{font-size:21px}h3{font-size:18px}.article-section{padding:22px 0}.inline-media{height:190px}.inline-media img{max-height:190px}.footer-main{grid-template-columns:1fr;padding-top:32px;gap:20px}.footer-bottom{flex-direction:column}.bottom-nav{position:fixed;bottom:0;left:0;right:0;display:grid;grid-template-columns:repeat(4,1fr);background:#fff;border-top:1px solid var(--border);z-index:15;padding-bottom:env(safe-area-inset-bottom)}.bottom-nav a{text-align:center;padding:10px 0;color:var(--ocean);font-size:13px;font-weight:700}.bottom-nav a[aria-current]{color:var(--blue)}.top-button{bottom:72px;right:13px}.main-btn{height:40px;padding:0 14px}.notice-banner{padding:16px}.page-layout{gap:15px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition:none!important}}