:root {
  --notice: #CDB88C;
  --notice-ink: #2B2719;
  --nav-surface: #FFFFFF;
  --nav-ink: #1D1D22;
  --nav-ink-muted: #5D5B66;
  --nav-line: rgba(29,29,34,.1);
  --on-accent: #FFFFFF;
  --bg: #1C1B21;
  --bg-panel: #24232A;
  --bg-panel-2: #2E2D35;
  --border: #3A3942;
  --accent: #2A6DF4;
  --accent-dark: #1A3F94;
  --frame-glow: #8FB2FF;
  --text: #F2F1F5;
  --text-muted: #A4A2AD;
  --text-soft: rgba(242,241,245,.74);
  --on-blue-line: rgba(242,241,245,.5);
  --success: #3FBF7F;
  --warn: #D6B26E;
  --error: #E5554B;
  --window-surface: #F7F7F9;
  --window-ink: #1D1D22;
  --window-ink-muted: #6C6A75;
  --window-side: #EFEFF3;
  --window-card: #FFFFFF;
  --window-line: rgba(29,29,34,.08);
  --window-line-strong: rgba(29,29,34,.16);
  --window-fill: rgba(29,29,34,.07);
  --window-stroke: rgba(255,255,255,.55);
  --window-shadow: 0 28px 70px rgba(8,18,60,.22);
  --ctl-shadow: 0 1px 2px rgba(29,29,34,.14), 0 0 0 .5px rgba(29,29,34,.08);
  --switch-off: #D3D2DA;
  --tl-red: #FF5F57;
  --tl-yellow: #FEBC2E;
  --tl-green: #28C840;
  --tl-edge: rgba(0,0,0,.12);
  --clear: transparent;
  --veil: rgba(0,0,0,.48);
  --panel-blue: rgba(26,63,148,.38);
  --font-display: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-bold: 600;
  --r-pill: 999px;
  --r-circle: 50%;
  --r-frame: 40px;
  --r-panel: 32px;
  --r-window: 14px;
  --r-card: 10px;
  --r-item: 7px;
  --r-ctl: 6px;
  --r-field: 5px;
  --r-line: 2px;
  --gutter: 24px;
  --content-max: 1200px;
  --reading-max: 800px;
  --header-max: 1280px;
  --shell: min(1200px, 92vw);
  --section-space: 96px;
  --duration: 240ms;
  --ease: cubic-bezier(.2,.6,.3,1);
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 24px; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
[hidden] { display: none !important; }
img, svg { vertical-align: middle; max-width: 100%; }
img { height: auto; }
button, input, select, textarea { font: inherit; }
button, a { -webkit-tap-highlight-color: var(--clear); }
button { cursor: pointer; }
a { color: inherit; text-decoration: none; }
a:hover { text-underline-offset: 4px; }
:focus-visible { outline: 2px solid var(--frame-glow); outline-offset: 3px; }
.topbar :focus-visible { outline-color: var(--accent); }
h1, h2, h3 { font-family: var(--font-display); font-weight: var(--weight-normal); text-wrap: balance; line-height: 1.25; }
h1 { font-size: clamp(34px, 3.3vw, 48px); }
h2 { font-size: clamp(26px, 2.6vw, 36px); }
h3 { font-size: 22px; }
p { margin-top: 0; }
strong { font-weight: var(--weight-bold); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--bg-panel);
  color: var(--text);
}
pre code { white-space: pre; overflow-wrap: normal; word-break: normal; }
:where(main, section, article, aside, div, li) { min-width: 0; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}
.keep { white-space: nowrap; }
.wrap {
  width: 100%;
  max-width: calc(var(--content-max) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { max-width: calc(var(--reading-max) + var(--gutter) * 2); }
.shell { width: var(--shell); margin-inline: auto; }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.section-head { max-width: 720px; margin-bottom: 36px; }
.eyebrow { font-size: 13.5px; color: var(--text-muted); }
.muted { color: var(--text-muted); }
.text-link { color: var(--frame-glow); text-decoration: underline; text-underline-offset: 4px; }
.stack > * + * { margin-top: 24px; }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 24px; }
.grid > *, .cluster > * { min-width: 0; }
.panel, .card {
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: var(--r-panel);
  background: var(--bg-panel);
  color: var(--text);
}
.panel > :last-child, .card > :last-child { margin-bottom: 0; }
.card h3 { margin-top: 0; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-width: 172px;
  min-height: 48px;
  padding: 12px 30px;
  border: 1px solid var(--clear);
  border-radius: var(--r-pill);
  font-size: 15.5px;
  font-weight: var(--weight-medium);
  line-height: 1.4;
  text-align: center;
  background: var(--bg-panel-2);
  color: var(--text);
}
.btn svg { width: 18px; height: 18px; flex-shrink: 0; }
.btn--primary { background: var(--on-accent); color: var(--accent); }
.btn--primary:hover, .btn--primary.is-hover { color: var(--accent-dark); }
.btn--ghost { background: var(--clear); border-color: var(--on-blue-line); color: var(--text); }
.btn--ghost:hover, .btn--ghost.is-hover { border-color: var(--text); }
.btn--blue { background: var(--accent); color: var(--on-accent); }
.btn--blue:hover { background: var(--accent-dark); color: var(--on-accent); }
.btn:active, .btn.is-active { transform: translateY(1px); }
.btn:disabled, .btn[aria-disabled="true"] { cursor: not-allowed; background: var(--bg-panel-2); color: var(--text-muted); border-color: var(--border); }
.btn.is-focus { outline: 2px solid var(--frame-glow); outline-offset: 3px; }
.notice { background: var(--notice); color: var(--notice-ink); font-size: 13.5px; line-height: 1; }
.notice__inner { display: flex; align-items: center; justify-content: space-between; min-height: 36px; gap: 24px; }
.notice__link { display: inline-flex; align-items: center; gap: 8px; }
.notice__link span { flex-shrink: 0; }
.notice__link:hover { text-decoration: underline; }
.topbar { position: relative; z-index: 50; background: var(--nav-surface); color: var(--nav-ink); }
.header-shell {
  width: 100%;
  max-width: min(100%, calc(var(--header-max) + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.topbar__inner { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 10px; flex-shrink: 0; font-family: var(--font-display); font-size: 17px; font-weight: var(--weight-bold); letter-spacing: -.005em; }
.brand__mark { width: 30px; height: 30px; flex-shrink: 0; }
.mainnav { margin-left: auto; min-width: 0; }
.mainnav__list { display: flex; align-items: center; list-style: none; gap: 2px; margin: 0; padding: 0; }
.mainnav__link { display: inline-flex; align-items: center; justify-content: center; padding: 8px 15px; border-radius: var(--r-pill); font-size: 14.5px; line-height: 1.2; color: var(--nav-ink-muted); white-space: nowrap; }
.mainnav__link:hover { color: var(--nav-ink); }
.mainnav__link[aria-current="page"] { background: var(--accent); color: var(--on-accent); }
.header-tools { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.language { position: relative; }
.lang { display: inline-flex; align-items: center; justify-content: center; gap: 7px; height: 34px; padding: 0 14px; border: 1px solid var(--nav-line); border-radius: var(--r-pill); background: var(--nav-surface); color: var(--nav-ink); font-size: 13.5px; white-space: nowrap; }
.lang svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 1.3; flex-shrink: 0; }
.lang__caret { font-size: 11px; color: var(--nav-ink-muted); }
.lang-short { display: none; }
.language-menu { position: absolute; top: calc(100% + 12px); right: 0; min-width: 180px; padding: 8px; margin: 0; list-style: none; border: 1px solid var(--nav-line); border-radius: var(--r-window); background: var(--nav-surface); color: var(--nav-ink); }
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 8px 12px; border-radius: var(--r-item); }
.language-menu a:hover, .language-menu a[aria-current] { background: var(--window-side); color: var(--nav-ink); }
.menu-toggle { display: none; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; padding: 10px; border: 1px solid var(--nav-line); border-radius: var(--r-item); background: var(--nav-surface); color: var(--nav-ink); }
.menu-toggle svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.5; }
.mobile-drawer { position: absolute; top: 100%; left: 0; right: 0; z-index: 52; max-height: calc(100dvh - 100px); overflow-y: auto; overscroll-behavior: contain; padding: 16px var(--gutter) 24px; background: var(--nav-surface); color: var(--nav-ink); border-top: 1px solid var(--nav-line); }
.mobile-drawer ul { list-style: none; margin: 0; padding: 0; }
.mobile-drawer a { display: flex; align-items: center; width: 100%; min-height: 44px; padding: 12px 16px; border-radius: var(--r-item); }
.mobile-drawer a[aria-current="page"] { background: var(--accent); color: var(--on-accent); }
.mobile-drawer__languages { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--nav-line); }
.menu-veil { position: fixed; inset: 0; z-index: 40; border: 0; background: var(--veil); color: var(--text); }
.site-footer { border-top: 1px solid var(--border); padding-top: 64px; padding-bottom: 32px; background: var(--bg); color: var(--text); }
.footer-grid { display: grid; grid-template-columns: 1.35fr 1fr 1.2fr 1fr; gap: 40px; }
.footer-brand p { margin-top: 20px; max-width: 300px; color: var(--text-muted); }
.footer-title { margin: 0 0 18px; font-size: 15px; font-weight: var(--weight-medium); }
.footer-list { display: grid; gap: 10px; margin: 0; padding: 0; list-style: none; font-size: 14px; color: var(--text-muted); }
.footer-list a:hover { color: var(--text); text-decoration: underline; }
.footer-bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px; margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--border); font-size: 13px; color: var(--text-muted); }
.prose { overflow-wrap: break-word; }
.prose :where(h2,h3) { scroll-margin-top: 32px; margin-top: 2em; margin-bottom: .7em; }
.prose p, .prose li { line-height: 1.85; }
.prose a { color: var(--frame-glow); text-decoration: underline; text-underline-offset: 4px; }
.prose :not(pre) > code { padding: 2px 5px; border-radius: var(--r-field); background: var(--bg-panel-2); color: var(--text); }
.prose img { max-width: 100%; }
.reveal { opacity: 1; transform: none; }
.reveal-pending { opacity: 0; transform: translateY(16px); transition: opacity 600ms var(--ease), transform 600ms var(--ease); }
.reveal.shown { opacity: 1; transform: none; }
.decorated, [data-hero-visual], .hero { overflow-x: clip; }
@media (max-width: 1280px) {
  .mainnav__link { padding-inline: 11px; font-size: 14px; }
  .topbar__inner { gap: 16px; }
  html:not([lang="zh-CN"]):not([lang="zh-TW"]) .mainnav { display: none; }
  html:not([lang="zh-CN"]):not([lang="zh-TW"]) .menu-toggle { display: inline-flex; }
  html:not([lang="zh-CN"]):not([lang="zh-TW"]) .header-tools { margin-left: auto; }
}
@media (max-width: 1000px) {
  .mainnav { display: none; }
  .menu-toggle { display: inline-flex; }
  .header-tools { margin-left: auto; }
  .notice__aside { display: none; }
  .footer-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
}
@media (max-width: 768px) {
  h1 { font-size: clamp(24px, 4.2vw, 30px); }
}
@media (max-width: 640px) {
  :root { --gutter: 16px; --section-space: 64px; }
  .grid, .footer-grid { grid-template-columns: minmax(0,1fr); }
  .notice__inner { padding-block: 8px; line-height: 1.5; }
  .notice__link { font-size: 11px; }
  .brand { gap: 7px; font-size: 15px; }
  .brand__mark { width: 28px; height: 28px; }
  .header-tools { gap: 8px; margin-left: auto; }
  .topbar__inner { gap: 8px; }
  .lang { padding-inline: 10px; min-height: 44px; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .panel, .card { padding: 22px; }
  .tilt, [data-tilt] { transform: none !important; }
  .footer-grid { gap: 32px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal-pending { opacity: 1; transform: none; }
}