:root {
  --c-bg: #F4F8F8;
  --c-panel: #FFFFFF;
  --c-panel-2: #EAF2F2;
  --c-panel-soft: #F7FAFA;
  --c-line: #DDE6E6;
  --c-line-soft: #E9EFEF;
  --c-accent: #1C8C55;
  --c-accent-dark: #136B40;
  --c-accent-soft: #E3F2EA;
  --c-ink: #1C2422;
  --c-ink-muted: #5C6966;
  --c-ink-faint: #8B9794;
  --c-success: #2A9D63;
  --c-warn: #C4880F;
  --c-error: #CC4A3B;
  --c-warn-ink: #785208;
  --c-error-ink: #AD392D;
  --c-on-accent: #FFFFFF;
  --c-wash-mint: #E2F3EC;
  --c-wash-sky: #E4EEF8;
  --c-light-1: #E3B5AB;
  --c-light-2: #E6D29E;
  --c-light-3: #A9D3BE;
  --c-switch-off: #D3DDDB;
  --c-sky-dot: #8FB5DD;
  --c-glass: rgba(255, 255, 255, 0.74);
  --c-ring: rgba(28, 140, 85, 0.17);
  --c-ring-soft: rgba(92, 105, 102, 0.16);
  --c-mask: #000000;
  --c-clear: transparent;
  --c-veil: rgba(28, 36, 34, 0.28);
  --sh-soft: 0 1px 2px rgba(28, 36, 34, 0.04), 0 6px 16px -8px rgba(28, 36, 34, 0.08);
  --sh-win: 0 2px 6px rgba(28, 36, 34, 0.05), 0 30px 60px rgba(40, 66, 64, 0.11);
  --sh-float: 0 4px 12px rgba(28, 36, 34, 0.07), 0 44px 80px rgba(40, 66, 64, 0.20);
  --sh-cta: 0 12px 24px -12px rgba(19, 107, 64, 0.60), inset 0 1px 0 rgba(255, 255, 255, 0.16);
  --sh-knob: 0 1px 2px rgba(28, 36, 34, 0.24);
  --sh-seg: 0 1px 2px rgba(28, 36, 34, 0.08);
  --halo-dot: 0 0 0 4px var(--c-accent-soft);
  --halo-sky: 0 0 0 4px var(--c-wash-sky);
  --r-win: 24px;
  --r-card: 20px;
  --r-btn: 12px;
  --r-bar: 14px;
  --r-cell: 10px;
  --r-input: 8px;
  --r-pill: 999px;
  --r-circle: 50%;
  --f-display: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --f-body: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
  --f-mono: 'JetBrains Mono', 'SFMono-Regular', Menlo, Consolas, 'Liberation Mono', monospace;
  --mast-h: 72px;
  --gutter: 64px;
  --side: var(--gutter);
  --content-max: 1312px;
  --reading-max: 800px;
  --duration: 180ms;
  --ease: ease;
}
*, *::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(--c-bg);
  color: var(--c-ink);
  font-family: var(--f-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
svg, .icon, .dot { flex-shrink: 0; }
img { height: auto; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, a { -webkit-tap-highlight-color: var(--c-clear); }
a { color: inherit; text-decoration: none; }
a, button { touch-action: manipulation; }
button { color: var(--c-ink); }
:focus-visible { outline: 3px solid var(--c-accent-dark); outline-offset: 4px; }
[hidden] { display: none !important; }
h1, h2, h3, h4 { font-family: var(--f-display); line-height: 1.25; text-wrap: balance; }
h1 { margin: 0 0 24px; font-size: clamp(34px, 3.2vw, 48px); font-weight: 800; letter-spacing: -0.02em; }
h2 { margin: 0 0 20px; font-size: clamp(26px, 2.5vw, 36px); font-weight: 800; letter-spacing: -0.02em; }
h3 { margin: 0 0 12px; font-size: 21px; font-weight: 700; }
p { margin: 0 0 18px; }
ul, ol { padding-left: 1.4em; }
nav ul, .plain-list { list-style: none; margin: 0; padding: 0; }
code, pre, kbd { font-family: var(--f-mono); }
code { overflow-wrap: anywhere; font-size: 0.9em; }
pre {
  max-width: 100%;
  min-width: 0;
  margin: 0;
  padding: 22px;
  overflow-x: auto;
  background: var(--c-panel-soft);
  color: var(--c-ink);
  border-radius: var(--r-cell);
  line-height: 1.75;
  tab-size: 2;
}
pre code { white-space: pre; overflow-wrap: normal; word-break: normal; font-size: 13px; }
blockquote { margin-inline: 0; }
hr { border: 0; border-top: 1px solid var(--c-line); margin-block: 32px; }
small, .small { font-size: 13px; }
.muted { color: var(--c-ink-muted); }
.accent, h1 em, h2 em { color: var(--c-accent); font-style: normal; }
.nowrap { white-space: nowrap; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}
.wrap, .shell {
  width: 100%;
  max-width: calc(var(--content-max) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.shell { max-width: 1440px; }
.reading { max-width: calc(var(--reading-max) + var(--gutter) * 2); }
.section { padding-top: 88px; padding-bottom: 88px; }
.section-white { background: var(--c-panel); color: var(--c-ink); border-block: 1px solid var(--c-line); }
.section-head { max-width: 720px; margin-bottom: 36px; }
.section-head p { color: var(--c-ink-muted); }
.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid > *, .hero > *, .footer-grid > *, .tabs > *, .prose, .prose div { min-width: 0; }
.stack > * + * { margin-top: 24px; }
.flow > * + * { margin-top: 16px; }
.prose { line-height: 1.85; overflow-wrap: break-word; }
.prose h2 { margin-top: 56px; scroll-margin-top: 28px; }
.prose h3 { margin-top: 32px; }
.prose a:not(.btn) { color: var(--c-accent-dark); text-decoration: underline; text-underline-offset: 4px; }
.prose li + li { margin-top: 8px; }
.prose :not(pre) > code { background: var(--c-panel-2); color: var(--c-ink); padding: 2px 5px; border-radius: var(--r-input); }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  padding: 12px 22px;
  max-width: 100%;
  border: 1px solid var(--c-clear);
  border-radius: var(--r-btn);
  font-size: 16px;
  line-height: 1.5;
  font-weight: 600;
  text-align: center;
  transition: transform var(--duration) var(--ease), background-color var(--duration) var(--ease), border-color var(--duration) var(--ease);
}
.btn svg { width: 18px; height: 18px; }
.btn-solid { background: var(--c-accent); color: var(--c-on-accent); box-shadow: var(--sh-cta); }
.btn-solid:hover, .btn-solid.is-hover { background: var(--c-accent-dark); color: var(--c-on-accent); transform: translateY(-1px); }
.btn-line { background: var(--c-panel); color: var(--c-ink); border-color: var(--c-line); box-shadow: var(--sh-soft); }
.btn-line svg { color: var(--c-ink-muted); }
.btn-line:hover, .btn-line.is-hover { border-color: var(--c-accent); transform: translateY(-1px); }
.btn-quiet { background: var(--c-clear); color: var(--c-accent-dark); }
.btn-quiet:hover { background: var(--c-accent-soft); color: var(--c-accent-dark); }
.btn:active { transform: translateY(1px); }
.btn:disabled, .btn[aria-disabled="true"] {
  background: var(--c-panel-2);
  color: var(--c-ink-muted);
  border-color: var(--c-line);
  box-shadow: none;
  cursor: not-allowed;
  transform: none;
}
.btn-small { min-height: 44px; padding: 9px 16px; font-size: 14px; }
.card, .panel {
  padding: 28px;
  border: 1px solid var(--c-line);
  border-radius: var(--r-card);
  background: var(--c-panel);
  color: var(--c-ink);
  box-shadow: var(--sh-soft);
}
.panel { border-radius: var(--r-win); box-shadow: var(--sh-win); }
.card p:last-child, .panel p:last-child { margin-bottom: 0; }
.card-link { display: block; transition: border-color var(--duration), box-shadow var(--duration); }
.card-link:hover { border-color: var(--c-accent); box-shadow: var(--sh-win); }
.reveal { opacity: 1; transform: none; }
.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(14px); }
.reveal-ready .reveal { transition: opacity 500ms ease, transform 500ms ease; }
.stage {
  position: relative;
  overflow: hidden;
  overflow-x: clip;
  background:
    radial-gradient(30% 34% at 0% 0%, var(--c-wash-mint) 0%, var(--c-clear) 72%),
    radial-gradient(58% 72% at 100% 100%, var(--c-wash-sky) 0%, var(--c-clear) 74%),
    radial-gradient(26% 30% at 100% 0%, var(--c-wash-sky) 0%, var(--c-clear) 70%),
    var(--c-bg);
  color: var(--c-ink);
}
.decorated { position: relative; overflow-x: clip; }
.masthead, #site-header { position: relative; z-index: 50; }
.mast-row {
  height: var(--mast-h);
  display: flex;
  align-items: center;
  gap: 28px;
  justify-content: space-between;
  position: relative;
  z-index: 52;
}
.header-shell {
  width: 100%;
  max-width: min(100%, calc(1280px + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.mast-brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  flex-shrink: 0;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: -0.015em;
}
.mast-mark { width: 34px; height: 34px; flex-shrink: 0; border-radius: var(--r-cell); box-shadow: var(--sh-soft); }
.mainnav { min-width: 0; margin-left: auto; }
.mainnav ul { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: 34px; }
.mainnav a { display: block; padding-block: 12px; font-size: 15px; font-weight: 500; color: var(--c-ink-muted); white-space: nowrap; }
.mainnav a:hover { color: var(--c-ink); }
.mainnav a[aria-current="page"] { color: var(--c-ink); font-weight: 700; }
.header-tools { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.lang-control { position: relative; }
.lang-pick {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 36px;
  padding: 7px 13px;
  border: 1px solid var(--c-line);
  border-radius: var(--r-cell);
  background: var(--c-glass);
  color: var(--c-ink);
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
}
.lang-pick .chevron { color: var(--c-ink-muted); font-size: 11px; }
.lang-short { display: none; }
.language-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  min-width: 180px;
  padding: 6px;
  border-radius: var(--r-bar);
  border: 1px solid var(--c-line);
  box-shadow: var(--sh-win);
  background: var(--c-panel);
  color: var(--c-ink);
}
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 9px 12px; border-radius: var(--r-input); }
.language-menu a:hover, .language-menu a[aria-current="true"] { background: var(--c-panel-2); color: var(--c-accent-dark); }
.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 10px;
  border: 1px solid var(--c-line);
  border-radius: var(--r-cell);
  background: var(--c-panel);
  color: var(--c-ink);
}
.menu-toggle svg { width: 22px; height: 22px; }
.mobile-drawer {
  position: absolute;
  top: var(--mast-h);
  inset-inline: 0;
  z-index: 54;
  max-height: calc(100dvh - var(--mast-h));
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 16px var(--gutter) 24px;
  border-top: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
  background: var(--c-panel);
  color: var(--c-ink);
  box-shadow: var(--sh-win);
}
.mobile-drawer a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 12px 14px; border-radius: var(--r-input); }
.mobile-drawer a:hover, .mobile-drawer a[aria-current] { background: var(--c-panel-2); color: var(--c-accent-dark); }
.mobile-languages { margin-top: 16px; border-top: 1px solid var(--c-line); padding-top: 12px; }
.nav-veil { position: fixed; inset: var(--mast-h) 0 0; z-index: 51; background: var(--c-veil); color: var(--c-ink); border: 0; width: 100%; cursor: default; }
.site-footer { padding-top: 64px; padding-bottom: 28px; border-top: 1px solid var(--c-line); background: var(--c-panel); color: var(--c-ink); }
.footer-grid { display: grid; grid-template-columns: 1.5fr 0.8fr 1.2fr 0.8fr; gap: 40px; }
.footer-brand p { margin-top: 20px; max-width: 28em; color: var(--c-ink-muted); font-size: 14px; }
.footer-heading { margin: 0 0 16px; font-size: 14px; font-weight: 700; }
.footer-links { list-style: none; margin: 0; padding: 0; }
.footer-links a { display: inline-block; padding-block: 7px; color: var(--c-ink-muted); font-size: 14px; overflow-wrap: anywhere; }
.footer-links a:hover { color: var(--c-accent-dark); }
.footer-bottom { margin-top: 44px; padding-top: 24px; border-top: 1px solid var(--c-line); color: var(--c-ink-muted); font-size: 13px; }
@media (max-width: 1180px) {
  :root { --gutter: 40px; }
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 1000px) {
  .mainnav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
}
@media (min-width: 1001px) {
  .mobile-drawer, .nav-veil { display: none !important; }
}
@media (max-width: 768px) {
  h1 { font-size: clamp(24px, 4.5vw, 30px); }
  .grid-3 { grid-template-columns: 1fr; }
  .section { padding-top: 56px; padding-bottom: 56px; }
}
@media (max-width: 640px) {
  :root { --gutter: 20px; }
  .mast-row { gap: 10px; }
  .mast-brand { font-size: 16px; gap: 8px; }
  .header-tools { gap: 8px; margin-left: auto; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .lang-pick { min-height: 44px; padding-inline: 11px; }
  .grid-2, .grid-4, .footer-grid { grid-template-columns: 1fr; }
  .card, .panel { padding: 22px; }
  .tilt, .bench-tilt, [data-tilt] { transform: none !important; }
  .footer-grid { gap: 28px; }
  .footer-brand { max-width: 100%; }
  pre { padding: 16px; }
}
@media (max-width: 360px) {
  :root { --gutter: 16px; }
  .mast-brand { font-size: 14px; }
  .mast-mark { width: 30px; height: 30px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
  .reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
}