:root {
  --bg: #F9F9F9;
  --panel: #FFFFFF;
  --panel-2: #F1F1F1;
  --border: #E6E6E6;
  --border-strong: #D4D4D4;
  --accent: #0A0A0A;
  --accent-dark: #000000;
  --text: #141414;
  --muted: #6B6B6B;
  --faint: #B5B5B5;
  --on-accent: #FFFFFF;
  --success: #2F7A4E;
  --warn: #9A6A12;
  --error: #B8382D;
  --switch-off: #D9D9D9;
  --switch-hi: #2A2A2A;
  --knob-edge: #EDEDED;
  --ring-1: #EFEFEF;
  --ring-2: #F2F2F2;
  --ring-3: #F4F4F4;
  --clear: transparent;
  --sheen: rgba(255, 255, 255, 0.05);
  --track-depth: rgba(0, 0, 0, 0.35);
  --puddle: rgba(0, 0, 0, 0.20);
  --puddle-mid: rgba(0, 0, 0, 0.08);
  --veil: rgba(0, 0, 0, 0.20);
  --shadow-hair: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-panel: 0 1px 2px rgba(0, 0, 0, 0.04), 0 24px 64px rgba(0, 0, 0, 0.06);
  --shadow-btn: 0 1px 2px rgba(0, 0, 0, 0.14), 0 8px 18px -8px rgba(0, 0, 0, 0.40);
  --track-inset: inset 0 1px 3px rgba(0, 0, 0, 0.10);
  --shadow-track: 0 1px 2px rgba(0, 0, 0, 0.10), 0 20px 40px -18px rgba(0, 0, 0, 0.45);
  --shadow-knob: 0 1px 1px rgba(0, 0, 0, 0.16), 0 12px 26px -8px rgba(0, 0, 0, 0.50), inset 0 -4px 8px rgba(0, 0, 0, 0.06), inset 0 1px 0 rgba(255, 255, 255, 1);
  --shadow-mark: 0 2px 6px rgba(0, 0, 0, 0.22);
  --shadow-fab: 0 2px 4px rgba(0, 0, 0, 0.12), 0 16px 32px -12px rgba(0, 0, 0, 0.45);
  --font-display: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "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;
  --weight-regular: 400;
  --weight-medium: 500;
  --weight-strong: 600;
  --r-pill: 999px;
  --r-panel: 24px;
  --r-small: 12px;
  --r-mark: 23%;
  --r-round: 50%;
  --gutter: 32px;
  --wrap: 1184px;
  --reading: 800px;
  --header-width: 1280px;
  --nav-h: 64px;
  --section-space: 180px;
  --trk-w: 400px;
  --trk-h: 184px;
  --pad: 16px;
  --knob: 152px;
  --ring-d: 740px;
  --travel: calc(var(--trk-w) - var(--knob) - 2 * var(--pad));
  --ease-out: cubic-bezier(0.2, 0.8, 0.2, 1);
  --motion-fast: 150ms;
  --motion-reveal: 600ms;
  --motion-switch: 700ms;
  --motion-delay: 300ms;
  --cycle: 8s;
}
*, *::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;
}
h1, h2, h3, h4, p, ul, ol, blockquote, figure, pre, dl, dd { margin: 0; }
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: var(--weight-regular); text-wrap: balance; }
h1 { font-size: clamp(34px, 3.4vw, 48px); line-height: 1.14; letter-spacing: -0.02em; }
h2 { font-size: clamp(28px, 4vw, 56px); line-height: 1.2; letter-spacing: -0.02em; }
h3 { font-size: 24px; line-height: 1.35; }
ul, ol { padding-left: 1.4em; }
a { color: inherit; text-underline-offset: 4px; }
a:hover { text-decoration-thickness: 2px; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, a, input, select, textarea { -webkit-tap-highlight-color: var(--clear); }
img, svg { vertical-align: middle; max-width: 100%; }
img { height: auto; }
svg { flex-shrink: 0; }
button svg, a svg { width: 18px; height: 18px; flex-shrink: 0; }
button:disabled { cursor: not-allowed; }
[hidden] { display: none !important; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
strong { font-weight: var(--weight-medium); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; font-size: 0.88em; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: var(--r-small);
  background: var(--panel-2);
  color: var(--text);
  font-size: 14px;
  line-height: 1.8;
  tab-size: 2;
}
pre code { overflow-wrap: normal; white-space: pre; font-size: inherit; }
.wrap { width: 100%; max-width: calc(var(--wrap) + var(--gutter) * 2); margin-inline: auto; padding-inline: var(--gutter); }
.reading { width: 100%; max-width: calc(var(--reading) + var(--gutter) * 2); margin-inline: auto; padding-inline: var(--gutter); }
.section { padding-top: calc(var(--section-space) / 2); padding-bottom: calc(var(--section-space) / 2); }
.section-title { margin-bottom: 48px; }
.section-intro { max-width: 680px; margin-top: 20px; color: var(--muted); }
.stack > * + * { margin-top: 24px; }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.grid > *, .stack > *, .wrap > *, .reading > * { min-width: 0; }
.muted { color: var(--muted); }
.mono { font-family: var(--font-mono); }
.nowrap { white-space: nowrap; }
.small { font-size: 13px; }
.vh { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.skip { position: absolute; left: 16px; top: 12px; z-index: 100; padding: 8px 14px; border-radius: var(--r-pill); background: var(--accent); color: var(--on-accent); text-decoration: none; }
.skip:not(:focus), .blog-skip:not(:focus) { width: 1px; height: 1px; padding: 0; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.prose { min-width: 0; overflow-wrap: break-word; }
.prose > * + *, .prose section > * + * { margin-top: 24px; }
.prose h2 { margin-top: 64px; font-size: clamp(28px, 3vw, 36px); }
.prose h3 { margin-top: 36px; }
.prose p, .prose li { line-height: 1.9; }
.prose li + li { margin-top: 8px; }
.prose img { display: block; }
.prose :is(h2, h3, h4), [id] { scroll-margin-top: 24px; }
.btn, .nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid var(--clear);
  border-radius: var(--r-pill);
  font-size: 15px;
  font-weight: var(--weight-medium);
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  transition: background-color var(--motion-fast), border-color var(--motion-fast), transform var(--motion-fast);
}
.btn svg { width: 16px; height: 16px; }
.btn-primary, .nav-cta { background: var(--accent); color: var(--on-accent); box-shadow: var(--shadow-btn); }
.btn-primary:hover, .nav-cta:hover, .btn-primary.is-hover { background: var(--accent-dark); color: var(--on-accent); }
.btn-ghost { background: var(--panel); color: var(--text); border-color: var(--border); box-shadow: var(--shadow-hair); }
.btn-ghost:hover, .btn-ghost.is-hover { border-color: var(--border-strong); }
.btn:hover { transform: translateY(-1px); }
.btn:active, .btn.is-active { transform: translateY(1px); box-shadow: var(--shadow-hair); }
.btn.is-focus { outline: 2px solid var(--accent); outline-offset: 3px; }
.btn:disabled, .btn[aria-disabled="true"] { background: var(--panel-2); color: var(--muted); border-color: var(--border); box-shadow: none; transform: none; }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.panel, .card { min-width: 0; padding: 32px; border: 1px solid var(--border); border-radius: var(--r-panel); background: var(--panel); color: var(--text); box-shadow: var(--shadow-panel); }
.card > * + * { margin-top: 16px; }
.card p { color: var(--muted); }
.site-header, #site-header { position: relative; z-index: 50; }
.bar {
  position: relative;
  min-height: var(--nav-h);
  width: 100%;
  max-width: min(100%, calc(var(--header-width) + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  gap: 28px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-size: 15px; font-weight: var(--weight-medium); letter-spacing: -0.01em; white-space: nowrap; flex-shrink: 0; }
.brand-mark { display: block; width: 28px; height: 28px; flex-shrink: 0; }
.site-nav { margin-left: auto; min-width: 0; }
.nav-list { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; }
.nav-list li { display: flex; align-items: center; }
.nav-list li + li::before { content: "·"; color: var(--faint); padding-inline: 12px; font-size: 14px; }
.nav-list a { position: relative; padding-block: 6px; color: var(--muted); text-decoration: none; font-size: 14px; line-height: 1; white-space: nowrap; transition: color var(--motion-fast); }
.nav-list a:hover, .nav-list a[aria-current="page"] { color: var(--text); }
.nav-list a[aria-current="page"]::after { content: ""; position: absolute; inset-inline: 0; bottom: 0; height: 1px; background: var(--accent); color: var(--on-accent); }
.bar-end { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.bar-end::before { content: ""; width: 1px; height: 16px; margin-right: 8px; background: var(--border); color: var(--text); }
.nav-cta { min-height: 34px; padding-inline: 16px; font-size: 13px; white-space: nowrap; }
.language { position: relative; }
.lang { appearance: none; display: inline-flex; align-items: center; justify-content: center; gap: 6px; min-height: 34px; padding: 7px 10px; border: 0; border-radius: var(--r-pill); background: var(--clear); color: var(--muted); font-size: 13px; line-height: 1; cursor: pointer; }
.lang:hover { background: var(--panel-2); color: var(--text); }
.lang svg { width: 14px; height: 14px; }
.lang .caret { width: 10px; height: 10px; }
.lang-short { display: none; }
.language-menu { position: absolute; right: 0; top: calc(100% + 10px); min-width: 180px; padding: 8px; list-style: none; border: 1px solid var(--border); border-radius: var(--r-small); background: var(--panel); color: var(--text); box-shadow: var(--shadow-panel); z-index: 54; }
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 8px 12px; text-decoration: none; border-radius: var(--r-small); }
.language-menu a:hover, .language-menu a[aria-current] { background: var(--panel-2); color: var(--text); }
.menu-toggle { display: none; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; padding: 10px; border: 1px solid var(--border); border-radius: var(--r-pill); background: var(--panel); color: var(--text); }
.menu-toggle svg { width: 20px; height: 20px; }
.menu-veil { position: fixed; inset: var(--nav-h) 0 0; z-index: 51; border: 0; background: var(--veil); color: var(--text); }
.mobile-drawer { position: absolute; top: 100%; inset-inline: var(--gutter); z-index: 53; padding: 16px; max-height: calc(100dvh - var(--nav-h) - 16px); overflow-y: auto; overscroll-behavior: contain; background: var(--panel); color: var(--text); border: 1px solid var(--border); border-radius: var(--r-panel); box-shadow: var(--shadow-panel); }
.mobile-drawer ul { list-style: none; padding: 0; margin: 0; }
.mobile-drawer a { display: flex; align-items: center; width: 100%; min-height: 44px; padding: 10px 12px; text-decoration: none; }
.mobile-drawer a:hover, .mobile-drawer a[aria-current] { background: var(--panel-2); color: var(--text); border-radius: var(--r-small); }
.drawer-label { margin-top: 16px; padding: 12px; color: var(--muted); font-size: 12px; border-top: 1px solid var(--border); }
.preview-menu { display: none; position: relative; }
.preview-menu > summary { list-style: none; }
.preview-menu > summary::-webkit-details-marker { display: none; }
.preview-menu nav { position: absolute; right: 0; top: calc(100% + 8px); width: min(280px, calc(100vw - 32px)); max-height: calc(100dvh - 90px); overflow-y: auto; padding: 16px; background: var(--panel); color: var(--text); border: 1px solid var(--border); border-radius: var(--r-panel); box-shadow: var(--shadow-panel); }
.preview-menu nav a { display: flex; align-items: center; min-height: 44px; width: 100%; text-decoration: none; }
.site-footer, #site-footer { margin-top: 90px; border-top: 1px solid var(--border); }
.footer-inner { padding-top: 64px; padding-bottom: 96px; }
.footer-grid { display: grid; grid-template-columns: 1.2fr 0.8fr 1.4fr 0.7fr; gap: 40px; }
.footer-grid > * { min-width: 0; }
.footer-brand p { max-width: 290px; margin-top: 20px; color: var(--muted); font-size: 14px; }
.footer-heading { margin-bottom: 16px; font-size: 13px; font-weight: var(--weight-medium); }
.footer-links { list-style: none; padding: 0; margin: 0; }
.footer-links a { display: inline-block; padding-block: 5px; color: var(--muted); text-decoration: none; font-size: 13px; }
.footer-links a:hover { color: var(--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(--border); color: var(--muted); font-size: 12px; }
.legal-links { display: flex; flex-wrap: wrap; gap: 16px; }
.reveal { opacity: 1; }
.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(16px); }
.reveal-ready .reveal { transition: opacity var(--motion-reveal) var(--ease-out), transform var(--motion-reveal) var(--ease-out); }
.reveal.shown { opacity: 1; transform: none; }
.decorated { position: relative; overflow-x: clip; }
@media (max-width: 1100px) {
  .bar { gap: 20px; }
  .nav-list li + li::before { padding-inline: 8px; }
  .lang-label { display: none; }
  .lang-short { display: inline; }
}
@media (max-width: 960px) {
  :root { --gutter: 24px; }
  .site-nav { display: none; }
  .bar-end { margin-left: auto; }
  .bar-end::before { display: none; }
  .menu-toggle { display: inline-flex; }
  .preview-menu { display: block; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 768px) {
  h1 { font-size: clamp(24px, 7.2vw, 30px); }
}
@media (max-width: 640px) {
  :root { --gutter: 20px; --section-space: 100px; }
  .bar { gap: 8px; }
  .bar-end { gap: 4px; margin-left: auto; }
  .bar-end > .nav-cta { display: none; }
  .brand { gap: 8px; font-size: 14px; }
  .grid, .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .card, .panel { padding: 24px; }
  .section-title { margin-bottom: 32px; }
  .tilt, [data-tilt] { transform: none !important; }
  .btn { min-height: 44px; padding-inline: 20px; }
  .footer-inner { padding-bottom: 100px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
  .reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
  .btn:hover { transform: none; }
}