:root {
  --blue: #2563EB; --blue-deep: #1B377E; --blue-soft: #E9F0FD; --blue-tint: #CFE0FA;
  --navy: #23375F; --coral: #F05A50; --coral-deep: #D8463C; --coral-soft: #FDECEA;
  --paper: #FCFAF6; --paper-2: #F5F0E7; --card: #FFFFFF;
  --ink: #1E2A44; --ink-2: #5B6680; --ink-3: #97A0B4; --border: #E7E0D2; --border-2: #D8D0BE;
  --disp: 'Archivo', 'Noto Sans SC', sans-serif;
  --sans: 'Hanken Grotesk', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Segoe UI', sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;
  --cn: 'Noto Sans SC', 'Hanken Grotesk', sans-serif;
  --sh-sm: 0 1px 2px rgba(35,55,95,.06), 0 1px 3px rgba(35,55,95,.05);
  --sh-md: 0 10px 30px -10px rgba(35,55,95,.18), 0 2px 8px rgba(35,55,95,.06);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 16px; line-height: 1.75; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
a { color: var(--blue-deep); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }
::selection { background: var(--navy); color: #fff; }
.wrap { max-width: 768px; margin: 0 auto; padding: 0 24px; }

nav { position: sticky; top: 0; z-index: 100; background: rgba(252,250,246,.85); backdrop-filter: saturate(180%) blur(16px); -webkit-backdrop-filter: saturate(180%) blur(16px); border-bottom: 1px solid var(--border); }
.nav-inner { max-width: 1160px; margin: 0 auto; padding: 0 28px; display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-family: var(--disp); font-weight: 800; font-size: 18px; letter-spacing: -.02em; color: var(--navy); }
.brand:hover { text-decoration: none; }
.brand img { width: 28px; height: 28px; border-radius: 8px; box-shadow: var(--sh-sm); }
.nav-right { display: flex; align-items: center; gap: 18px; font-size: 14px; }
.nav-right a { color: var(--ink-2); font-weight: 500; }
.nav-right a:hover { color: var(--blue); text-decoration: none; }
.lang { font-family: var(--mono); border: 1px solid var(--border-2); padding: 5px 10px; border-radius: 8px; color: var(--ink-3) !important; font-weight: 700; font-size: 12px; }
.lang:hover { border-color: var(--blue-tint); background: var(--blue-soft); color: var(--blue) !important; }

.doc { padding: 60px 0 88px; }
.doc .kicker { font-family: var(--mono); font-size: 12px; font-weight: 700; letter-spacing: .14em; color: var(--coral); text-transform: uppercase; }
.doc h1 { font-family: var(--disp); color: var(--navy); font-size: clamp(32px, 5vw, 44px); font-weight: 900; letter-spacing: -.025em; line-height: 1.12; margin: 14px 0 12px; }
:lang(zh-CN) .doc h1 { font-family: var(--cn); }
.doc .meta { font-family: var(--mono); font-size: 13px; color: var(--ink-3); margin-bottom: 38px; padding-bottom: 30px; border-bottom: 1px solid var(--border); }
.doc h2 { font-family: var(--disp); color: var(--navy); font-size: 23px; font-weight: 800; letter-spacing: -.01em; margin: 44px 0 12px; scroll-margin-top: 80px; }
:lang(zh-CN) .doc h2 { font-family: var(--cn); }
.doc h3 { font-size: 17px; font-weight: 700; color: var(--ink); margin: 28px 0 8px; }
.doc p { color: var(--ink-2); margin: 12px 0; }
.doc ul, .doc ol { color: var(--ink-2); margin: 12px 0 12px 4px; padding-left: 22px; }
.doc li { margin: 7px 0; }
.doc li::marker { color: var(--coral); }
.doc strong { color: var(--ink); font-weight: 600; }
.doc .lead { font-size: 18px; color: var(--ink); }
.callout { background: var(--blue-soft); border: 1px solid var(--blue-tint); border-radius: 14px; padding: 18px 22px; margin: 24px 0; font-size: 15px; color: var(--ink-2); }
.callout strong { color: var(--blue-deep); }
.tldr { background: var(--card); border: 1px solid var(--border); border-radius: 16px; padding: 22px 24px; margin: 8px 0 34px; box-shadow: var(--sh-sm); }
.tldr h2 { margin: 0 0 8px; font-family: var(--mono); font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3); }
.tldr ul { margin: 0 0 0 4px; }
.tldr li { font-size: 14.5px; }
.contact-card { background: var(--card); border: 1px solid var(--border); border-radius: 18px; padding: 26px 28px; margin: 28px 0; box-shadow: var(--sh-sm); }
.contact-card h3 { margin-top: 0; color: var(--navy); }
hr.rule { border: none; border-top: 1px solid var(--border); margin: 42px 0; }

footer { background: #14213D; color: #9DACC8; padding: 40px 0; margin-top: 24px; }
.foot-inner { max-width: 1160px; margin: 0 auto; padding: 0 28px; display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; font-size: 13.5px; color: #7F8DAA; }
.foot-links a { color: #9DACC8; margin-left: 18px; font-weight: 500; }
.foot-links a:hover { color: #fff; text-decoration: none; }
.foot-links a:first-child { margin-left: 0; }
@media (max-width: 560px) { .doc { padding: 40px 0 60px; } }