:root{--brand:#1E4FFF;--brand-2:#00C2FF;--ink:#0B1B3F;--muted:#5B6B8C;--bg:#fff;--bg-alt:#F4F7FD;--line:#E3E9F5;--card:#fff;--hero-a:#EEF3FF;--hero-b:#E6FAFF;
--radius:14px;--shadow:0 6px 24px rgba(11,27,63,.08);--font:Inter,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;color-scheme:light}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){--ink:#E8EEFF;--muted:#9AA8C7;--bg:#0A1022;--bg-alt:#0F1830;--line:#1E2A47;--card:#111B35;--hero-a:#0E1A3E;--hero-b:#082232;--shadow:0 6px 24px rgba(0,0,0,.35);color-scheme:dark}}
:root[data-theme="dark"]{--ink:#E8EEFF;--muted:#9AA8C7;--bg:#0A1022;--bg-alt:#0F1830;--line:#1E2A47;--card:#111B35;--hero-a:#0E1A3E;--hero-b:#082232;--shadow:0 6px 24px rgba(0,0,0,.35);color-scheme:dark}
*{box-sizing:border-box}html,body{margin:0}
body{background:var(--bg);color:var(--ink);font:16px/1.7 var(--font);-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}
img,svg{max-width:100%}
h1,h2,h3{line-height:1.25;margin:0 0 .5em;letter-spacing:-.01em}
h1{font-size:clamp(30px,5vw,50px)}h2{font-size:clamp(24px,3.4vw,34px)}h3{font-size:19px}
p{margin:0 0 1em}.muted{color:var(--muted)}
.container{max-width:1160px;margin:0 auto;padding:0 16px}
.section{padding:72px 0}.section-alt{background:var(--bg-alt)}
.section-head{max-width:720px;margin:0 0 36px}.section-head.center{margin-inline:auto;text-align:center}
.eyebrow{display:inline-block;font-size:13px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--brand);margin-bottom:10px}
/* header */
.site-header{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.site-header .container{display:flex;align-items:center;gap:24px;height:68px}
.logo{display:flex;align-items:center;gap:10px;color:var(--ink);font-weight:700;font-size:20px;white-space:nowrap}
.logo:hover{text-decoration:none}.logo svg{width:34px;height:34px;flex:none}
.nav{display:flex;align-items:center;gap:4px;margin-left:auto}
.nav>a,.nav .dd>button{color:var(--ink);font:inherit;font-size:15px;padding:8px 12px;border-radius:8px;background:none;border:0;cursor:pointer}
.nav>a:hover,.nav .dd>button:hover{background:var(--bg-alt);text-decoration:none}
.nav a.active,.nav .dd>button.active{color:var(--brand)}
.dd{position:relative}.dd-menu{display:none;position:absolute;top:100%;left:0;min-width:220px;padding:8px;background:var(--card);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow)}
.dd:hover .dd-menu,.dd:focus-within .dd-menu{display:block}
.dd-menu a{display:block;padding:8px 12px;border-radius:8px;color:var(--ink)}.dd-menu a:hover{background:var(--bg-alt);text-decoration:none}
.tools{display:flex;align-items:center;gap:6px}
.icon-btn{display:inline-flex;align-items:center;justify-content:center;min-width:38px;height:38px;padding:0 10px;border:1px solid var(--line);border-radius:10px;background:none;color:var(--ink);font:inherit;font-size:14px;cursor:pointer}
.icon-btn:hover{background:var(--bg-alt);text-decoration:none}
.nav-toggle{display:none}
@media (max-width:860px){
 .nav-toggle{display:inline-flex}.site-header .container{gap:10px}.tools{margin-left:auto}
 .nav{display:none;position:absolute;top:68px;left:0;right:0;flex-direction:column;align-items:stretch;gap:0;padding:8px 16px 16px;background:var(--bg);border-bottom:1px solid var(--line)}
 body.nav-open .nav{display:flex}
 .nav>a,.nav .dd>button{text-align:left;width:100%;padding:12px}
 .dd-menu{display:block;position:static;box-shadow:none;border:0;padding:0 0 0 12px;background:none}
}
/* buttons */
.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 22px;border-radius:10px;font-weight:600;font-size:15px;border:1px solid transparent;cursor:pointer;font-family:inherit}
.btn:hover{text-decoration:none}
.btn-primary{background:var(--brand);color:#fff}.btn-primary:hover{background:#1640d9}
.btn-ghost{border-color:var(--line);color:var(--ink);background:var(--card)}.btn-ghost:hover{border-color:var(--brand);color:var(--brand)}
.btn-row{display:flex;flex-wrap:wrap;gap:12px}
/* hero */
.hero{padding:96px 0 80px;background:radial-gradient(1200px 500px at 85% -10%,var(--hero-b),transparent 60%),linear-gradient(180deg,var(--hero-a),var(--bg))}
.hero p.lead{font-size:clamp(17px,2vw,20px);color:var(--muted);max-width:640px;margin-bottom:28px}
.hero-stats{display:flex;flex-wrap:wrap;gap:28px;margin-top:44px;color:var(--muted);font-size:14px}
.hero-stats b{display:block;color:var(--ink);font-size:20px}
.page-hero{padding:64px 0 48px;background:linear-gradient(180deg,var(--hero-a),var(--bg))}
.page-hero p.lead{font-size:18px;color:var(--muted);max-width:680px;margin-bottom:24px}
/* grid & cards */
.grid-2,.grid-3,.grid-4{display:grid;gap:20px}
.grid-2{grid-template-columns:repeat(auto-fit,minmax(min(100%,420px),1fr))}
.grid-3{grid-template-columns:repeat(auto-fit,minmax(min(100%,290px),1fr))}
.grid-4{grid-template-columns:repeat(auto-fit,minmax(min(100%,240px),1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow)}
a.card{display:block;color:inherit;transition:transform .15s,border-color .15s}a.card:hover{transform:translateY(-3px);border-color:var(--brand);text-decoration:none}
.card p:last-child{margin-bottom:0}.card .more{color:var(--brand);font-weight:600;font-size:14px}
.card-icon{width:46px;height:46px;border-radius:12px;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff;margin-bottom:16px}
.card-icon svg{width:24px;height:24px}
.tag{display:inline-block;font-size:12px;padding:2px 10px;border-radius:99px;background:var(--bg-alt);border:1px solid var(--line);color:var(--muted);margin:0 6px 6px 0}
.dc-card h3{display:flex;align-items:center;gap:10px}.dc-card .code{font-size:12px;font-weight:700;color:#fff;background:var(--brand);border-radius:6px;padding:2px 8px}
ul.checks{list-style:none;padding:0;margin:0}ul.checks li{position:relative;padding-left:26px;margin:6px 0}
ul.checks li::before{content:"";position:absolute;left:4px;top:.55em;width:10px;height:6px;border-left:2px solid var(--brand);border-bottom:2px solid var(--brand);transform:rotate(-45deg)}
/* table */
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius);background:var(--card)}
table.spec{width:100%;border-collapse:collapse;min-width:640px;font-size:15px}
table.spec th,table.spec td{padding:14px 18px;text-align:left;border-bottom:1px solid var(--line);white-space:nowrap}
table.spec th{background:var(--bg-alt);font-weight:600;font-size:14px;color:var(--muted)}
table.spec tr:last-child td{border-bottom:0}table.spec td:last-child{color:var(--brand);font-weight:600}
/* faq */
.faq{max-width:820px}.faq details{border-bottom:1px solid var(--line);padding:16px 0}
.faq summary{cursor:pointer;font-weight:600;list-style:none;display:flex;justify-content:space-between;gap:16px}
.faq summary::after{content:"+";color:var(--brand);font-size:20px;line-height:1}.faq details[open] summary::after{content:"−"}
.faq summary::-webkit-details-marker{display:none}.faq details p{margin:10px 0 0;color:var(--muted)}
/* cta */
.cta-band{background:linear-gradient(120deg,var(--brand),#0A8BD8 60%,var(--brand-2));color:#fff;border-radius:20px;padding:44px;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:20px}
.cta-band h2{margin:0 0 6px}.cta-band p{margin:0;opacity:.9}
.cta-band .btn{background:#fff;color:var(--brand)}
/* prose */
.prose{max-width:820px}.container.prose{max-width:1160px}.container.prose>*{max-width:820px}.prose h2{font-size:22px;margin-top:36px}.prose p,.prose li{color:var(--ink)}.prose ul{padding-left:22px}
.prose .updated{color:var(--muted);font-size:14px}
/* form */
.form{display:grid;gap:16px}.form label{display:grid;gap:6px;font-weight:600;font-size:14px}
.form input,.form select,.form textarea{font:inherit;font-weight:400;font-size:15px;padding:12px 14px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--ink);width:100%}
.form input:focus,.form select:focus,.form textarea:focus{outline:2px solid var(--brand);outline-offset:1px;border-color:transparent}
.form textarea{min-height:150px;resize:vertical}
.form .hp{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}
.form-status{min-height:1.5em;margin:0;font-size:14px}.form-status.ok{color:#12A150}.form-status.err{color:#D9364C}
.contact-item{display:flex;gap:14px;align-items:flex-start;margin-bottom:18px}.contact-item .card-icon{margin:0;flex:none;width:40px;height:40px}
/* footer */
.site-footer{border-top:1px solid var(--line);padding:56px 0 28px;background:var(--bg-alt);font-size:14px}
.footer-grid{display:grid;grid-template-columns:2fr repeat(3,1fr);gap:32px}
@media (max-width:760px){.footer-grid{grid-template-columns:1fr 1fr}.footer-grid>div:first-child{grid-column:1/-1}}
.site-footer h4{font-size:14px;margin:0 0 12px}.site-footer ul{list-style:none;padding:0;margin:0}.site-footer li{margin:6px 0}
.site-footer a{color:var(--muted)}.site-footer a:hover{color:var(--brand)}
.footer-bottom{display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px;margin-top:40px;padding-top:20px;border-top:1px solid var(--line);color:var(--muted)}
@media (max-width:600px){.section{padding:52px 0}.hero{padding:64px 0 56px}.cta-band{padding:30px 22px}.card{padding:22px}}