:root {
  --c-bg: #FFFFFF;
  --c-panel: #F6F7F7;
  --c-panel-2: #101513;
  --c-border: #E3E6E4;
  --c-accent: #2DB83D;
  --c-accent-dark: #1D8A2B;
  --c-text: #111814;
  --c-muted: #5D6661;
  --c-success: #2DB83D;
  --c-warn: #E8A317;
  --c-error: #E0484D;
  --c-ink-soft: #2B3530;
  --c-on-ink: #FFFFFF;
  --win-bg: #101513;
  --win-bg-hi: #131A17;
  --win-panel: #151B18;
  --win-raise: #1A211E;
  --win-line: #232A27;
  --win-edge: #D9DDDB;
  --win-text: #E8EDEA;
  --win-text-2: #BCC5C0;
  --win-muted: #8A948F;
  --win-dim: #5E6863;
  --win-track: #2A332F;
  --win-dot: #39423D;
  --win-knob-off: #8A948F;
  --accent-halo: rgba(45, 184, 61, 0.18);
  --accent-glow: rgba(45, 184, 61, 0.55);
  --focus-ring: rgba(17, 24, 20, 0.28);
  --veil: rgba(17, 24, 20, 0.28);
  --shadow-card: 0 1px 2px rgba(17, 24, 20, 0.05), 0 34px 60px -38px rgba(17, 24, 20, 0.38);
  --shadow-card-inset: inset 0 1px 0 rgba(255, 255, 255, 0.045);
  --shadow-fab: 0 1px 2px rgba(17, 24, 20, 0.12), 0 12px 28px -14px rgba(17, 24, 20, 0.45);
  --font-display: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --r-card: 28px;
  --r-panel: 16px;
  --r-table: 14px;
  --r-item: 10px;
  --r-chip: 8px;
  --r-mobile-card: 20px;
  --r-line: 2px;
  --r-pill: 999px;
  --r-circle: 50%;
  --w-content: 1120px;
  --w-reading: 800px;
  --w-header: 1280px;
  --h-nav: 72px;
  --gutter: 32px;
  --size-body: 16px;
  --size-small: 14px;
  --size-fine: 12px;
  --size-h1: clamp(34px, 3.2vw + 6px, 48px);
  --size-h2: clamp(26px, 2.4vw, 36px);
  --size-h3: 22px;
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;
  --weight-brand: 800;
  --weight-display: 900;
  --tracking-display: -0.035em;
  --tracking-heading: -0.02em;
  --ease: 200ms ease;
  --reveal-time: 600ms;
  --section-space: 112px;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: var(--size-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
[hidden] { display: none !important; }
img, svg, video { max-width: 100%; }
img { height: auto; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
a { color: inherit; text-underline-offset: 0.2em; }
a, button, summary { -webkit-tap-highlight-color: var(--focus-ring); }
:focus-visible { outline: 2px solid var(--c-text); outline-offset: 3px; }
h1, h2, h3 { font-family: var(--font-display); text-wrap: balance; overflow-wrap: break-word; }
h1 { font-size: var(--size-h1); font-weight: var(--weight-display); line-height: 1.14; letter-spacing: var(--tracking-heading); }
h2 { margin: 0 0 24px; font-size: var(--size-h2); line-height: 1.25; letter-spacing: var(--tracking-heading); font-weight: var(--weight-brand); }
h3 { margin: 0 0 16px; font-size: var(--size-h3); line-height: 1.4; font-weight: var(--weight-bold); }
p { margin: 0 0 20px; }
strong { font-weight: var(--weight-semibold); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; font-size: 0.9em; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 24px;
  border: 1px solid var(--win-line);
  border-radius: var(--r-panel);
  background: var(--win-panel);
  color: var(--win-text);
  line-height: 1.8;
  tab-size: 2;
}
pre code { overflow-wrap: normal; word-break: normal; white-space: pre; font-size: var(--size-small); }
blockquote { margin-inline: 0; }
hr { border: 0; border-top: 1px solid var(--c-border); margin-block: 40px; }
section, article, aside, main, nav, header, footer, div { min-width: 0; }
:where([id]) { scroll-margin-top: 24px; }
.wrap { width: 100%; max-width: calc(var(--w-content) + var(--gutter) * 2); margin-inline: auto; padding-inline: var(--gutter); }
.reading { max-width: calc(var(--w-reading) + var(--gutter) * 2); }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.section__intro { max-width: 680px; margin-bottom: 44px; }
.muted, .section__intro p { color: var(--c-muted); }
.keep { white-space: nowrap; }
.prose { overflow-wrap: break-word; }
.prose h2 { margin-top: 64px; }
.prose h3 { margin-top: 36px; }
.prose p, .prose li { line-height: 1.9; }
.prose li + li { margin-top: 8px; }
.prose > :first-child { margin-top: 0; }
.prose img { display: block; }
.prose pre { margin-block: 28px; }
.skip {
  position: absolute;
  left: 16px;
  top: 12px;
  clip-path: inset(50%);
  padding: 8px 14px;
  border-radius: var(--r-pill);
  background: var(--c-text);
  color: var(--c-on-ink);
  font-size: var(--size-small);
  text-decoration: none;
  z-index: 100;
}
.skip:focus { clip-path: none; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.ico { fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
.ico, .kicker__dot, .lamp { flex-shrink: 0; }

.masthead, #site-header { position: relative; z-index: 60; background: var(--c-bg); color: var(--c-text); }
.masthead { height: var(--h-nav); }
.masthead__inner {
  max-width: min(100%, calc(var(--w-header) + var(--gutter) * 2));
  height: var(--h-nav);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  gap: 44px;
  position: relative;
}
.brand { display: inline-flex; align-items: center; gap: 11px; flex-shrink: 0; text-decoration: none; color: var(--c-text); font-family: var(--font-display); font-weight: var(--weight-brand); font-size: 17px; letter-spacing: -0.015em; white-space: nowrap; }
.brand__mark { width: 30px; height: 30px; display: block; flex-shrink: 0; }
.desktop-nav { min-width: 0; }
.tabs { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: 4px; height: 100%; }
.tabs li { min-width: 0; }
.tabs a { position: relative; display: flex; align-items: center; height: var(--h-nav); padding-inline: 14px; color: var(--c-muted); font-size: 15px; font-weight: var(--weight-medium); text-decoration: none; white-space: nowrap; transition: color var(--ease); }
.tabs a::after { content: ""; position: absolute; left: 14px; right: 14px; bottom: 15px; height: 2px; border-radius: var(--r-line); background: var(--c-text); transform: scaleX(0); opacity: 0; transition: transform 280ms ease, opacity 280ms ease; }
.tabs a:hover { color: var(--c-text); }
.tabs a:hover::after { transform: scaleX(1); opacity: 0.18; }
.tabs a[aria-current="page"] { color: var(--c-text); font-weight: var(--weight-semibold); }
.tabs a[aria-current="page"]::after { transform: scaleX(1); opacity: 1; }
.header-tools { margin-left: auto; display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.language-control { position: relative; }
.lang { display: inline-flex; align-items: center; justify-content: center; gap: 8px; height: 36px; padding: 0 14px 0 12px; border: 1px solid var(--c-border); border-radius: var(--r-pill); background: var(--c-bg); color: var(--c-muted); font-size: var(--size-small); font-weight: var(--weight-medium); line-height: 1; white-space: nowrap; text-decoration: none; }
.lang:hover { color: var(--c-text); border-color: var(--c-text); }
.lang svg { width: 16px; height: 16px; }
.lang__caret { font-size: 11px; }
.lang__short { display: none; }
.language-menu { position: absolute; right: 0; top: calc(100% + 12px); width: 200px; margin: 0; padding: 8px; list-style: none; border: 1px solid var(--c-border); border-radius: var(--r-panel); background: var(--c-bg); color: var(--c-text); }
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 8px 12px; border-radius: var(--r-item); text-decoration: none; }
.language-menu a:hover, .language-menu a[aria-current="true"] { background: var(--c-panel); color: var(--c-text); }
.menu-toggle { display: none; min-width: 44px; min-height: 44px; align-items: center; justify-content: center; border: 1px solid var(--c-border); border-radius: var(--r-pill); background: var(--c-bg); color: var(--c-text); }
.menu-toggle svg { width: 20px; height: 20px; }
.mobile-drawer { position: absolute; top: var(--h-nav); left: 0; right: 0; z-index: 3; padding: 16px var(--gutter) 24px; max-height: calc(100dvh - var(--h-nav)); overflow-y: auto; overscroll-behavior: contain; background: var(--c-bg); color: var(--c-text); border-bottom: 1px solid var(--c-border); }
.mobile-drawer ul { list-style: none; margin: 0; padding: 0; }
.mobile-drawer a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 12px 16px; text-decoration: none; border-radius: var(--r-item); }
.mobile-drawer a:hover, .mobile-drawer a[aria-current] { background: var(--c-panel); color: var(--c-text); }
.mobile-drawer__languages { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--c-border); }
.nav-veil { position: fixed; inset: var(--h-nav) 0 0; z-index: 1; background: var(--veil); color: var(--c-text); border: 0; cursor: default; }

.hero { position: relative; overflow-x: clip; padding: 48px 24px 0; text-align: center; }
.kicker { display: inline-flex; align-items: center; gap: 10px; min-height: 32px; max-width: 100%; padding: 6px 14px 6px 12px; border: 1px solid var(--c-border); border-radius: var(--r-pill); background: var(--c-bg); color: var(--c-text); font-size: 13.5px; font-weight: var(--weight-medium); line-height: 1.4; text-decoration: none; }
.kicker:hover { border-color: var(--c-text); }
.kicker__dot { width: 8px; height: 8px; border-radius: var(--r-circle); background: var(--c-accent); box-shadow: 0 0 0 3px var(--accent-halo); }
.kicker__sep { width: 1px; height: 12px; background: var(--c-border); flex-shrink: 0; }
.kicker__go { color: var(--c-muted); }
.hero__title { margin: 20px auto 0; font-family: var(--font-display); font-weight: var(--weight-display); font-size: var(--size-h1); line-height: 1.14; letter-spacing: var(--tracking-display); color: var(--c-text); }
.hero__title > span { display: block; }
.hero__title .tone { color: var(--c-muted); }
.lede { max-width: 760px; margin: 16px auto 0; font-size: 17px; line-height: 1.6; color: var(--c-muted); }
.lede strong { color: var(--c-text); font-weight: var(--weight-semibold); }
.actions { display: flex; justify-content: center; align-items: center; flex-wrap: wrap; gap: 12px; margin-top: 26px; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 10px; min-height: 48px; max-width: 100%; padding: 12px 24px; border: 1px solid var(--c-text); border-radius: var(--r-pill); background: var(--c-bg); color: var(--c-text); font-family: var(--font-body); font-size: 15.5px; font-weight: var(--weight-semibold); line-height: 1.4; text-decoration: none; text-align: center; transition: box-shadow var(--ease), border-color var(--ease), background-color var(--ease); }
.btn svg { width: 18px; height: 18px; flex-shrink: 0; }
.btn--primary { background: var(--c-text); color: var(--c-on-ink); box-shadow: 0 0 0 0 var(--c-bg), 0 0 0 0 var(--c-accent); }
.btn--primary:hover, .btn--primary.is-hover { box-shadow: 0 0 0 3px var(--c-bg), 0 0 0 5px var(--c-accent); }
.btn--outline { background: var(--c-bg); color: var(--c-text); border-color: var(--c-border); }
.btn--outline:hover, .btn--outline.is-hover { border-color: var(--c-text); }
.btn__arrow { color: var(--c-muted); }
.btn:active { transform: translateY(1px); }
.btn:disabled, .btn[aria-disabled="true"] { background: var(--c-panel); color: var(--c-muted); border-color: var(--c-border); cursor: not-allowed; box-shadow: none; }
.btn.is-focus { outline: 2px solid var(--c-text); outline-offset: 3px; }
.platforms { display: flex; justify-content: center; align-items: center; flex-wrap: wrap; row-gap: 12px; margin: 22px 0 0; padding: 0; list-style: none; }
.platforms li { display: flex; align-items: center; }
.platforms li + li::before { content: ""; width: 1px; height: 14px; background: var(--c-border); flex-shrink: 0; }
.platforms a { display: inline-flex; align-items: center; gap: 8px; padding-inline: 20px; min-height: 22px; color: var(--c-muted); font-size: var(--size-small); font-weight: var(--weight-medium); text-decoration: none; }
.platforms a:hover { color: var(--c-text); }
.platforms svg { height: 16px; width: auto; flex-shrink: 0; display: block; }
.platforms .tux { height: 17px; }
.card, .panel { border: 1px solid var(--c-border); border-radius: var(--r-card); padding: 32px; background: var(--c-bg); color: var(--c-text); }
.panel--dark { background: var(--c-panel-2); color: var(--win-text); border-color: var(--win-line); }
.panel--dark p { color: var(--win-text-2); }
.panel--dark :focus-visible { outline-color: var(--win-text); }
.panel--dark .btn--outline { background: var(--win-raise); color: var(--win-text); border-color: var(--win-line); }
.panel--dark .btn--outline:hover { border-color: var(--win-text-2); }
.card-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.card-grid > * { min-width: 0; }
.reveal { opacity: 1; transform: none; }
.reveal.is-waiting { opacity: 0; transform: translateY(16px); transition: opacity var(--reveal-time) ease, transform var(--reveal-time) ease; }
.reveal.shown { opacity: 1; transform: none; }

.site-footer { margin-top: 80px; padding-top: 64px; padding-bottom: 96px; border-top: 1px solid var(--c-border); background: var(--c-bg); color: var(--c-text); }
.footer-grid { display: grid; grid-template-columns: 1.3fr 0.8fr 1.4fr 0.8fr; gap: 40px; }
.footer-brand p { margin-top: 20px; color: var(--c-muted); font-size: var(--size-small); max-width: 300px; }
.footer-title { margin: 0 0 16px; font-size: var(--size-small); font-weight: var(--weight-bold); }
.footer-links { margin: 0; padding: 0; list-style: none; }
.footer-links a { display: inline-block; padding-block: 5px; color: var(--c-muted); font-size: var(--size-small); text-decoration: none; }
.footer-links a:hover { color: var(--c-text); text-decoration: underline; }
.footer-bottom { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px; margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--c-border); color: var(--c-muted); font-size: var(--size-small); }
.footer-bottom p { margin: 0; }

@media (max-width: 1280px) {
  .masthead__inner { gap: 24px; }
}
@media (max-width: 1080px) {
  :root { --gutter: 24px; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 900px) {
  .desktop-nav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
}
@media (min-width: 901px) {
  .mobile-drawer, .nav-veil { display: none !important; }
}
@media (max-width: 768px) {
  :root { --size-h1: clamp(24px, 4vw, 30px); --section-space: 72px; }
  .hero__title { letter-spacing: var(--tracking-heading); }
  .hero { padding-top: 36px; }
  .lede { font-size: 15.5px; }
  .platforms a { padding-inline: 12px; }
}
@media (max-width: 640px) {
  :root { --gutter: 16px; }
  .masthead__inner { gap: 12px; }
  .masthead__inner .brand__text { display: none; }
  .lang__text { display: none; }
  .lang__short { display: inline; }
  .lang { padding-inline: 10px; min-height: 36px; }
  .hero { padding-inline: var(--gutter); }
  .hero__title { max-width: 100%; }
  .hero__title .tone { line-height: 1.3; margin-top: 4px; }
  .kicker { gap: 8px; font-size: var(--size-fine); }
  .card, .panel { padding: 24px; border-radius: var(--r-mobile-card); }
  .card-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-grid { gap: 32px 24px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-grid > :last-child { grid-column: 1 / -1; }
  .tilt, [data-tilt] { transform: none !important; }
  pre { padding: 16px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
  .reveal.is-waiting { opacity: 1; transform: none; }
}