:root {
  color-scheme: light;
  --bg: #E2EBFB;
  --bg-panel: #F6F9FF;
  --bg-panel-2: #D5E1F5;
  --border: #C6D4EC;
  --accent: #F0731E;
  --accent-dark: #C2550C;
  --accent-2: #FFB04A;
  --text: #16203A;
  --text-muted: #55627E;
  --success: #1F9D6B;
  --warn: #D99A12;
  --error: #D63B45;
  --sky-top: #D3E1FA;
  --sky-end: #F4F8FF;
  --apricot: #FFE3CC;
  --mint: #DDF2E8;
  --apricot-soft: rgba(255,227,204,.78);
  --white: #FFFFFF;
  --clear: transparent;
  --panel-82: rgba(246,249,255,.82);
  --panel-55: rgba(246,249,255,.55);
  --white-80: rgba(255,255,255,.8);
  --white-70: rgba(255,255,255,.7);
  --white-40: rgba(255,255,255,.4);
  --glass-hi: rgba(255,255,255,.34);
  --glass-lo: rgba(255,255,255,.06);
  --ink-70: rgba(22,32,58,.7);
  --ink-30: rgba(22,32,58,.3);
  --ink-12: rgba(22,32,58,.12);
  --ink-08: rgba(22,32,58,.08);
  --ink-06: rgba(22,32,58,.06);
  --success-16: rgba(31,157,107,.16);
  --accent-14: rgba(240,115,30,.14);
  --metal-hi: #EEF1F6;
  --metal-mid: #BEC6D3;
  --metal-lo: #8A93A3;
  --bezel: #151A26;
  --bezel-2: #2A3142;
  --flag-red: #E0303B;
  --flag-white: #FFFFFF;
  --flag-navy: #1A2A6C;
  --flag-blue: #24367E;
  --flag-edge: rgba(22,32,58,.16);
  --font-display: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans', 'Apple SD Gothic Neo', 'Microsoft YaHei', system-ui, sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Apple SD Gothic Neo', 'Malgun Gothic', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  --size-xs: 12px;
  --size-sm: 14px;
  --size-nav: 14.5px;
  --size-body: 16px;
  --size-button: 16.5px;
  --size-lede: 19px;
  --size-brand: 19px;
  --size-h1: clamp(52px,4.6vw,66px);
  --size-h2: clamp(30px,3.3vw,44px);
  --size-h3: 23px;
  --r-pill: 999px;
  --r-round: 50%;
  --r-card: 28px;
  --r-xl: 22px;
  --r-lg: 16px;
  --r-md: 12px;
  --r-sm: 8px;
  --r-mark: 10px;
  --r-window: 14px;
  --r-lid: 24px 24px 8px 8px;
  --r-bezel: 22px 22px 7px 7px;
  --r-deck: 2px 2px 18px 18px / 2px 2px 12px 12px;
  --r-notch: 0 0 8px 8px;
  --shadow-ink: 0 36px 80px rgba(22,32,58,.12);
  --shadow-card: 0 20px 44px rgba(22,32,58,.12), 0 2px 6px rgba(22,32,58,.06);
  --shadow-win: 0 24px 60px rgba(22,32,58,.18), 0 0 0 1px rgba(22,32,58,.06);
  --shadow-btn: 0 12px 28px rgba(22,32,58,.22);
  --shadow-chip: 0 4px 14px rgba(22,32,58,.07);
  --ring-hi: inset 0 0 0 1px rgba(255,255,255,.78);
  --gutter: 28px;
  --content-width: 1240px;
  --header-height: 68px;
  --anchor-space: 88px;
  --toc-space: 156px;
  --ease-ui: .2s ease;
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: var(--anchor-space); }
body { margin: 0; font-family: var(--font-body); font-size: var(--size-body); line-height: 1.7; color: var(--text); background: var(--sky-end); -webkit-font-smoothing: antialiased; }
a { color: inherit; text-underline-offset: .2em; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
button, a, summary { -webkit-tap-highlight-color: var(--accent-14); }
:where(a, button, input, select, textarea, summary, [tabindex]):focus-visible { outline: 2px solid var(--accent-dark); outline-offset: 3px; }
button:disabled, .btn[aria-disabled="true"] { opacity: .55; cursor: not-allowed; }
img { display: block; max-width: 100%; height: auto; }
svg { flex-shrink: 0; }
h1, h2, h3, h4 { font-family: var(--font-display); color: var(--text); text-wrap: balance; overflow-wrap: break-word; }
h1 { margin: 0 0 24px; font-size: var(--size-h1); line-height: 1.12; font-weight: 900; letter-spacing: -.02em; }
h2 { margin: 0 0 24px; font-size: var(--size-h2); line-height: 1.2; font-weight: 900; letter-spacing: -.02em; }
h3 { margin: 0 0 12px; font-size: var(--size-h3); line-height: 1.35; font-weight: 800; }
p { margin: 0; }
p + p { margin-top: 16px; }
ul, ol { padding-left: 1.5em; }
pre { max-width: 100%; overflow-x: auto; padding: 20px; background: var(--text); color: var(--bg-panel); border-radius: var(--r-lg); }
code { font-family: var(--font-mono); overflow-wrap: anywhere; }
pre code { overflow-wrap: normal; white-space: pre; }
hr { border: 0; border-top: 1px solid var(--border); margin-block: 32px; }
:where(main, section, article, aside, nav, .grid) > * { min-width: 0; }
.wrap { width: 100%; max-width: var(--content-width); margin-inline: auto; padding-inline: var(--gutter); }
.section { padding-top: 80px; padding-bottom: 80px; }
.section-head { text-align: center; max-width: 850px; margin: 0 auto 36px; }
.section-head p, .muted { color: var(--text-muted); }
.lede { font-size: var(--size-lede); color: var(--text-muted); }
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.no-break { white-space: nowrap; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; margin: -1px; }
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.plain-list { list-style: none; margin: 0; padding: 0; }
.grid { display: grid; gap: 24px; grid-template-columns: repeat(3,minmax(0,1fr)); }
.panel-card { padding: 28px; border-radius: var(--r-card); background: var(--bg-panel); box-shadow: var(--shadow-card), var(--ring-hi); min-width: 0; }
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 52px; padding: 0 32px; border: 0; border-radius: var(--r-pill); font-size: var(--size-button); font-weight: 700; line-height: 1.3; text-decoration: none; letter-spacing: .01em; gap: 8px; transition: transform var(--ease-ui), box-shadow var(--ease-ui), background var(--ease-ui); }
.btn:hover { transform: translateY(-1px); }
.btn--ink, .btn-primary { background: var(--text); color: var(--bg-panel); box-shadow: var(--shadow-btn); }
.btn--line, .btn-secondary { background: var(--white); color: var(--text); border: 1.5px solid var(--text); }
.btn--small { min-height: 38px; padding: 8px 18px; font-size: var(--size-sm); }
.btn:active { transform: translateY(0); box-shadow: var(--shadow-chip); }
.btn-demo-hover { transform: translateY(-1px); box-shadow: var(--shadow-btn); }
.btn-demo-focus { outline: 2px solid var(--accent-dark); outline-offset: 3px; }
.badge, .tag { display: inline-flex; align-items: center; gap: 6px; padding: 4px 12px; max-width: 100%; border-radius: var(--r-pill); background: var(--bg-panel-2); color: var(--text); font-size: var(--size-xs); font-weight: 700; overflow-wrap: anywhere; }
.badge--green { background: var(--success); color: var(--white); }
.badge--orange { background: var(--accent); color: var(--text); }
.status-dot { display: inline-block; width: 7px; height: 7px; border-radius: var(--r-round); background: var(--success); flex-shrink: 0; box-shadow: 0 0 0 3px var(--success-16); }
.reveal { transition: opacity .35s ease, transform .35s ease; }
.reveal.pending { opacity: 0; transform: translateY(16px); }
.reveal.shown { opacity: 1; transform: none; }
#server-status { position: relative; display: block; min-width: 0; min-height: 80px; width: 100%; max-width: 100%; overflow: hidden; margin-block: 24px; }
#server-status + * { margin-top: 24px; }

#site-header { position: relative; z-index: 50; min-height: var(--header-height); }
.topbar { position: relative; z-index: 50; }
.topbar__row { display: flex; align-items: center; gap: 24px; height: var(--header-height); flex-wrap: nowrap; }
.brand { display: inline-flex; align-items: center; gap: 10px; flex: none; text-decoration: none; color: var(--text); font-family: var(--font-display); font-weight: 800; font-size: var(--size-brand); letter-spacing: -.02em; line-height: 1.2; }
.brand__mark { display: block; width: 34px; height: 34px; flex-shrink: 0; border-radius: var(--r-mark); }
.brand__zh { color: var(--text-muted); font-weight: 500; }
.mainnav { flex: 1; display: flex; justify-content: center; min-width: 0; overflow-x: auto; scrollbar-width: thin; }
.mainnav__list { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; font-size: var(--size-nav); white-space: nowrap; }
.mainnav__list li { display: inline-flex; align-items: center; flex-shrink: 0; }
.mainnav__list li + li::before { content: "·"; margin: 0 11px; color: var(--ink-30); font-weight: 700; }
.mainnav__list a { display: inline-flex; align-items: center; min-height: 32px; text-decoration: none; color: var(--text-muted); padding: 6px 1px; transition: color var(--ease-ui); }
.mainnav__list a:hover, .mainnav__list a[aria-current="page"] { color: var(--text); }
.mainnav__list a[aria-current="page"] { font-weight: 700; }
.topbar__end { display: flex; align-items: center; gap: 12px; flex-shrink: 0; margin-left: auto; }
.language { position: relative; flex-shrink: 0; }
.lang { display: inline-flex; align-items: center; justify-content: center; gap: 4px; width: auto; min-width: 44px; min-height: 38px; font: inherit; font-size: var(--size-sm); line-height: 1.2; background: var(--clear); color: var(--text); border: 1px solid var(--clear); border-radius: var(--r-pill); padding: 7px 12px; white-space: nowrap; }
.lang:hover { background: var(--panel-82); border-color: var(--white-70); }
.lang span { white-space: nowrap; }
.lang__caret { font-size: var(--size-xs); color: var(--text-muted); }
.language-panel { position: absolute; z-index: 80; right: 0; top: calc(100% + 8px); width: 184px; padding: 8px; border: 1px solid var(--border); border-radius: var(--r-lg); background: var(--bg-panel); box-shadow: var(--shadow-card); }
.language-panel a { display: flex; align-items: center; width: 100%; min-height: 40px; padding: 8px 12px; border-radius: var(--r-sm); text-decoration: none; font-size: var(--size-sm); }
.language-panel a:hover, .language-panel a[aria-current="true"] { background: var(--bg-panel-2); }
[hidden] { display: none !important; }
.topbar__sep { width: 1px; height: 18px; background: var(--border); flex-shrink: 0; }
.login { display: inline-flex; align-items: center; justify-content: center; height: 38px; padding: 0 22px; border-radius: var(--r-pill); background: var(--text); color: var(--bg-panel); font-size: var(--size-sm); font-weight: 700; text-decoration: none; box-shadow: var(--shadow-chip); white-space: nowrap; transition: transform var(--ease-ui); }
.login:hover { transform: translateY(-1px); }
.menu-toggle { display: none; align-items: center; justify-content: center; flex-direction: column; gap: 4px; min-width: 44px; min-height: 44px; padding: 10px; border: 1px solid var(--border); border-radius: var(--r-sm); background: var(--bg-panel); color: var(--text); }
.menu-toggle__line { display: block; width: 20px; height: 2px; background: currentColor; }
.menu-drawer { position: fixed; z-index: 45; top: var(--header-height); left: 0; right: 0; height: calc(100dvh - var(--header-height)); max-height: calc(100dvh - var(--header-height)); padding: 20px var(--gutter) 40px; overflow-y: auto; overscroll-behavior: contain; background: var(--bg-panel); }
.menu-drawer ul { list-style: none; margin: 0; padding: 0; }
.menu-drawer a { display: flex; align-items: center; width: 100%; min-height: 44px; padding: 12px 16px; border-radius: var(--r-md); text-decoration: none; }
.menu-drawer a:hover, .menu-drawer a[aria-current] { background: var(--bg-panel-2); }
.menu-drawer__languages { border-top: 1px solid var(--border); margin-top: 20px; padding-top: 16px; }
.menu-veil { position: fixed; z-index: 40; inset: var(--header-height) 0 0; border: 0; background: var(--ink-30); }
html.nav-open { overflow: hidden; }

.site-footer { padding-top: 56px; padding-bottom: 24px; background: var(--bg-panel-2); border-top: 1px solid var(--white-80); box-shadow: var(--ring-hi); }
.footer-grid { display: grid; grid-template-columns: 1.25fr 1fr 1fr; gap: 48px; }
.footer-brand p { max-width: 320px; margin-top: 18px; color: var(--text-muted); }
.footer-title { font-size: var(--size-body); font-weight: 800; margin: 0 0 14px; }
.footer-links { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 6px 16px; list-style: none; margin: 0; padding: 0; }
.footer-links a, .footer-languages a, .footer-legal a { display: inline-flex; align-items: center; min-height: 28px; font-size: var(--size-sm); text-decoration: none; }
.footer-links a:hover, .footer-languages a:hover, .footer-legal a:hover { text-decoration: underline; }
.footer-languages { display: flex; flex-wrap: wrap; gap: 8px 22px; padding-block: 24px; margin-top: 24px; border-top: 1px solid var(--border); }
.footer-bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px 24px; color: var(--text-muted); font-size: var(--size-xs); }
.footer-legal { display: flex; flex-wrap: wrap; gap: 20px; }
@media (max-width: 1180px) {
  .topbar__row { gap: 16px; }
  .mainnav { justify-content: flex-start; }
  .mainnav__list li + li::before { margin-inline: 7px; }
}
@media (max-width: 1060px) {
  .mainnav, .nav-more { display: none; }
  .menu-toggle { display: inline-flex; }
  .topbar__end { margin-left: auto; }
  .topbar__sep { display: none; }
  .grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
}
@media (min-width: 1061px) {
  .menu-drawer, .menu-veil { display: none !important; }
}
@media (max-width: 768px) {
  :root { --gutter: 18px; --size-h1: 38px; --size-h2: 32px; }
  .section { padding-top: 56px; padding-bottom: 56px; }
  .btn { min-height: 48px; padding-inline: 26px; font-size: var(--size-body); }
  .btn--small { min-height: 38px; padding-inline: 18px; font-size: var(--size-sm); }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
}
@media (max-width: 640px) {
  .no-break { white-space: normal; }
  .grid { grid-template-columns: minmax(0,1fr); }
  .panel-card { padding: 22px; }
  .tilt, [data-tilt] { transform: none; }
  .topbar__row { gap: 8px; }
  .topbar__end { gap: 6px; margin-left: auto; }
  .brand { gap: 6px; font-size: var(--size-body); }
  .brand__mark { width: 28px; height: 28px; }
  .login { padding-inline: 14px; }
  .lang { padding-inline: 6px; font-size: var(--size-xs); }
  .footer-links { gap: 8px 16px; }
}
@media (max-width: 359px) {
  :root { --gutter: 16px; }
  .brand { font-size: var(--size-sm); }
  .brand__mark { width: 24px; height: 24px; }
  .login { padding-inline: 10px; }
  .lang { min-width: 44px; padding-inline: 4px; }
  .lang__caret { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal, .reveal.pending, .reveal.shown { opacity: 1; transform: none; transition: none; }
  .btn, .login, .mainnav__list a { transition: none; }
}