:root { color-scheme: light dark; --canvas:#f6f7fa; --surface:#fff; --text:#17202f; --muted:#596474; --line:#dce1e8; --accent:#165ac4; --soft:#e9f0fd; }
* { box-sizing:border-box; }
html { -webkit-text-size-adjust:100%; }
html:not([lang="zh-Hans"]) [data-lang="zh"], html[lang="zh-Hans"] [data-lang="en"] { display:none; }
body { margin:0; background:var(--canvas); color:var(--text); font:17px/1.7 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC",sans-serif; }
.site { min-height:100vh; display:flex; flex-direction:column; }
.wrap { width:min(100% - 40px,760px); margin-inline:auto; }
a { color:var(--accent); text-underline-offset:4px; overflow-wrap:anywhere; }
a:hover { text-decoration-thickness:2px; }
button,a,summary { -webkit-tap-highlight-color:transparent; }
:focus-visible { outline:3px solid var(--accent); outline-offset:4px; }
.site-header { border-bottom:1px solid var(--line); background:var(--surface); }
.header-row { display:flex; align-items:center; gap:16px; flex-wrap:wrap; padding-block:16px; }
.brand { display:inline-flex; align-items:center; gap:9px; font-weight:700; color:var(--text); text-decoration:none; margin-right:auto; min-height:44px; }
.brand img { border-radius:8px; }
nav { display:flex; align-items:center; gap:16px; flex-wrap:wrap; }
nav a { font-size:14px; text-decoration:none; display:inline-flex; align-items:center; min-height:44px; }
nav a[aria-current] { color:var(--text); font-weight:650; }
.lang-toggle { display:flex; border:1px solid var(--line); border-radius:12px; overflow:hidden; }
.lang-toggle button { border:0; background:transparent; color:var(--muted); font:inherit; font-size:14px; min-width:44px; min-height:44px; padding:6px 10px; cursor:pointer; }
.lang-toggle button[aria-pressed="true"] { background:var(--soft); color:var(--accent); font-weight:650; }
main { flex:1; padding-block:40px 56px; }
h1 { font-size:clamp(28px,5vw,40px); line-height:1.25; letter-spacing:-.025em; margin:0 0 20px; overflow-wrap:break-word; }
h2 { font-size:21px; line-height:1.4; margin:32px 0 10px; }
p { margin:0 0 18px; }
.hero { text-align:center; padding:12px 0 32px; }
.app-icon { border-radius:20px; margin-bottom:24px; }
.hero p { max-width:600px; margin-inline:auto; color:var(--muted); }
.actions { display:flex; gap:12px; flex-wrap:wrap; justify-content:center; margin-top:28px; }
.actions a,.contact > a:first-child { display:inline-flex; align-items:center; justify-content:center; min-height:46px; padding:10px 18px; border-radius:12px; text-decoration:none; font-weight:600; background:var(--accent); color:var(--surface); }
.actions a + a { background:var(--soft); color:var(--accent); }
.features { display:grid; grid-template-columns:repeat(3,minmax(0,1fr)); gap:16px; }
.features section { border:1px solid var(--line); border-radius:16px; padding:20px; background:var(--surface); }
.features h2 { margin:0 0 10px; font-size:19px; }
.features p { font-size:15px; color:var(--muted); margin:0; }
.contact { padding:24px; border:1px solid var(--line); border-radius:16px; background:var(--surface); margin:26px 0 32px; }
.contact > a { display:block; width:fit-content; margin-bottom:12px; }
.contact p { color:var(--muted); font-size:15px; margin-bottom:0; }
.faq { border-top:1px solid var(--line); }
details { border-bottom:1px solid var(--line); padding-block:16px; }
summary { cursor:pointer; font-weight:600; min-height:30px; }
details p { margin:14px 0 4px; color:var(--muted); }
.updated { color:var(--muted); font-size:14px; margin-top:36px; }
.site-footer { border-top:1px solid var(--line); padding-block:24px; display:flex; gap:8px 20px; flex-wrap:wrap; justify-content:space-between; color:var(--muted); font-size:14px; }
@media(max-width:600px) { .features { grid-template-columns:1fr; } .header-row { gap:8px 16px; } nav { order:3; width:100%; } main { padding-top:28px; } .hero { text-align:left; } .actions { justify-content:flex-start; } }
@media(prefers-color-scheme:dark) { :root { --canvas:#14171d; --surface:#1d222b; --text:#eef1f7; --muted:#aeb9ca; --line:#363e4c; --accent:#a6c6ff; --soft:#263b59; } }