:root {
  --c-bg: #FFFFFF;
  --c-panel: #F7F7F8;
  --c-panel-2: #EFEFF1;
  --c-border: #E4E4E7;
  --c-border-strong: #D6D6DB;
  --c-accent: #8F2F62;
  --c-accent-bright: #A8457A;
  --c-accent-dark: #6B2049;
  --c-accent-soft: #F6E8EF;
  --c-accent-ring: rgba(143, 47, 98, 0.16);
  --c-slate: #4A6585;
  --c-text: #17151A;
  --c-muted: #5F5C66;
  --c-faint: #9A97A1;
  --c-success: #3F7D5C;
  --c-warn: #B7791F;
  --c-error: #B83A3A;
  --c-on-accent: #FFFFFF;
  --c-tint-1: #F7EEF3;
  --c-tint-2: #EEF1F5;
  --c-tint-3: #F4F4F5;
  --c-tint-4: #F1F3F7;
  --c-grid: rgba(23, 21, 26, 0.05);
  --c-clear: rgba(255, 255, 255, 0);
  --c-veil: rgba(23, 21, 26, 0.24);
  --shadow-near: 0 1px 2px rgba(23, 21, 26, 0.06);
  --shadow-far: 0 12px 32px rgba(23, 21, 26, 0.08);
  --shadow-hover: 0 2px 4px rgba(23, 21, 26, 0.06), 0 22px 44px rgba(23, 21, 26, 0.11);
  --shadow-btn: 0 1px 2px rgba(107, 32, 73, 0.28), 0 8px 18px rgba(143, 47, 98, 0.18);
  --r-ctl: 6px;
  --r-card: 8px;
  --r-mini: 4px;
  --r-mark: 2px;
  --r-pill: 999px;
  --r-circle: 50%;
  --f-display: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --f-body: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --f-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --fs-micro: 9px;
  --fs-tiny: 9.5px;
  --fs-caption: 10px;
  --fs-window: 10.5px;
  --fs-small: 11px;
  --fs-note: 11.5px;
  --fs-xs: 12px;
  --fs-chip: 12.5px;
  --fs-label: 13px;
  --fs-meta: 13.5px;
  --fs-sm: 14px;
  --fs-nav: 14.5px;
  --fs-button: 15px;
  --fs-body: 16px;
  --fs-lead: 20px;
  --fs-h3: 22px;
  --fs-h2: 30px;
  --fs-h1: clamp(2.125rem, 1.4rem + 2vw, 3rem);
  --fs-hero: clamp(1.625rem, 1rem + 2.3vw, 2.875rem);
  --fs-h1-mobile: clamp(1.5rem, 5vw, 1.875rem);
  --fw-normal: 400;
  --fw-medium: 500;
  --fw-semi: 600;
  --fw-bold: 700;
  --fw-display: 800;
  --content: 1200px;
  --reading: 800px;
  --header-content: 1280px;
  --gutter: 24px;
  --header-h: 64px;
  --section-space: 100px;
  --card-w: 318px;
  --canvas-h: 240px;
  --stage-scale: 1;
  --deck-gap: 20px;
  --ease: cubic-bezier(.2, .65, .3, 1);
  --duration: 220ms;
  --reveal-duration: 500ms;
  --z-fab: 20;
  --z-header: 50;
  --z-veil: 1;
  --z-drawer: 2;
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
html, body { margin: 0; }
html.nav-open { overflow: hidden; }
body {
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--f-body);
  font-size: var(--fs-body);
  font-weight: var(--fw-normal);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
[hidden] { display: none !important; }
img, svg { max-width: 100%; vertical-align: middle; }
img { height: auto; }
button, input, select, textarea { font: inherit; }
button, a { -webkit-tap-highlight-color: var(--c-accent-ring); }
button { cursor: pointer; }
a { color: var(--c-slate); text-underline-offset: .2em; }
a:hover { color: var(--c-accent); }
a:focus-visible, button:focus-visible, summary:focus-visible,
input:focus-visible, select:focus-visible, textarea:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 3px;
  border-radius: var(--r-ctl);
}
h1, h2, h3, h4 {
  font-family: var(--f-display);
  color: var(--c-text);
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { font-size: var(--fs-h1); line-height: 1.16; font-weight: var(--fw-display); letter-spacing: -.02em; }
h2 { font-size: var(--fs-h2); line-height: 1.25; font-weight: var(--fw-display); letter-spacing: -.02em; }
h3 { font-size: var(--fs-h3); line-height: 1.35; font-weight: var(--fw-bold); }
p, ul, ol, dl, figure, blockquote { margin-top: 0; }
code, pre, kbd { font-family: var(--f-mono); }
code { overflow-wrap: anywhere; font-size: .9em; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 20px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-ctl);
  background: var(--c-panel);
  color: var(--c-text);
  font-size: var(--fs-sm);
  overscroll-behavior-x: contain;
}
pre code { white-space: pre; overflow-wrap: normal; word-break: normal; }
hr { border: 0; border-top: 1px solid var(--c-border); margin-block: 32px; }
.wrap {
  width: 100%;
  max-width: calc(var(--content) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { max-width: calc(var(--reading) + var(--gutter) * 2); }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.section__intro { max-width: 720px; margin-bottom: 36px; }
.eyebrow { color: var(--c-accent); font-size: var(--fs-label); font-weight: var(--fw-bold); letter-spacing: .06em; }
.muted { color: var(--c-muted); }
.mono { font-family: var(--f-mono); }
.keep { white-space: nowrap; }
.center { text-align: center; }
.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 > *, .split > *, .workbench > *, .footer-grid > * { min-width: 0; }
.split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 64px; align-items: center; }
.decorated, .hero, [data-hero-visual] { position: relative; overflow-x: clip; }
.decorated__svg { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.card, .panel {
  min-width: 0;
  padding: 24px;
  background: var(--c-bg);
  color: var(--c-text);
  border: 1px solid var(--c-border);
  border-radius: var(--r-card);
}
.card { box-shadow: var(--shadow-near), var(--shadow-far); }
.panel { background: var(--c-panel); color: var(--c-text); }
.card h3, .panel h3 { margin-top: 0; }
.card p:last-child, .panel p:last-child { margin-bottom: 0; }
.actions { margin-top: 26px; display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }
.actions--start { justify-content: flex-start; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  max-width: 100%;
  padding: 10px 22px;
  border-radius: var(--r-ctl);
  font-family: var(--f-body);
  font-size: var(--fs-button);
  font-weight: var(--fw-semi);
  line-height: 1.4;
  text-align: center;
  text-decoration: none;
  border: 1px solid var(--c-border-strong);
  background: var(--c-bg);
  color: var(--c-text);
}
.btn svg { width: 16px; height: 16px; flex-shrink: 0; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.btn--primary { background: var(--c-accent); color: var(--c-on-accent); border-color: var(--c-accent-dark); box-shadow: var(--shadow-btn); }
.btn--primary:hover, .btn--primary.is-hover { background: var(--c-accent-dark); color: var(--c-on-accent); }
.btn--ghost { background: var(--c-bg); color: var(--c-text); box-shadow: var(--shadow-near); }
.btn--ghost:hover, .btn--ghost.is-hover { background: var(--c-panel); color: var(--c-text); }
.btn--ghost svg { color: var(--c-muted); }
.btn--link { background: var(--c-clear); color: var(--c-slate); border-color: var(--c-clear); }
.btn:active, .btn.is-active { box-shadow: inset var(--shadow-near); }
.btn.is-focus { outline: 2px solid var(--c-accent); outline-offset: 3px; }
.btn:disabled, .btn[aria-disabled="true"] { background: var(--c-panel-2); color: var(--c-muted); border-color: var(--c-border); box-shadow: none; cursor: not-allowed; }
.masthead { position: relative; z-index: var(--z-header); height: var(--header-h); background: var(--c-bg); color: var(--c-text); border-bottom: 1px solid var(--c-border); }
.masthead__inner {
  height: 100%;
  max-width: min(100%, calc(var(--header-content) + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  gap: 24px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--c-text); font-family: var(--f-display); font-weight: var(--fw-display); font-size: var(--fs-body); letter-spacing: -.01em; flex-shrink: 0; }
.brand:hover { color: var(--c-text); }
.brand__mark { width: 30px; height: 30px; display: block; flex-shrink: 0; }
.topnav { margin-left: auto; min-width: 0; }
.dotnav { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: 0; }
.dotnav li { display: flex; align-items: center; }
.dotnav li + li::before { content: "·"; color: var(--c-faint); font-weight: var(--fw-bold); padding-inline: 11px; }
.dotnav a { display: block; color: var(--c-muted); text-decoration: none; font-size: var(--fs-nav); font-weight: var(--fw-medium); padding: 6px 2px; white-space: nowrap; }
.dotnav a:hover { color: var(--c-text); }
.dotnav a[aria-current="page"] { color: var(--c-accent); font-weight: var(--fw-bold); }
.header-tools { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.language { position: relative; }
.lang { display: inline-flex; align-items: center; justify-content: center; gap: 6px; height: 34px; padding-inline: 12px; background: var(--c-bg); color: var(--c-text); border: 1px solid var(--c-border); border-radius: var(--r-ctl); font-family: var(--f-body); font-size: var(--fs-meta); font-weight: var(--fw-medium); box-shadow: var(--shadow-near); white-space: nowrap; }
.lang:hover { background: var(--c-panel); color: var(--c-text); }
.lang__globe { width: 14px; height: 14px; flex-shrink: 0; fill: none; stroke: currentColor; stroke-width: 1.4; color: var(--c-muted); }
.lang__caret { color: var(--c-muted); font-size: var(--fs-small); }
.lang__short { display: none; }
.language-menu { position: absolute; right: 0; top: calc(100% + 8px); width: 190px; list-style: none; margin: 0; padding: 6px; background: var(--c-bg); color: var(--c-text); border: 1px solid var(--c-border); border-radius: var(--r-card); box-shadow: var(--shadow-near), var(--shadow-far); z-index: var(--z-drawer); }
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 10px 12px; color: var(--c-muted); text-decoration: none; border-radius: var(--r-ctl); }
.language-menu a:hover, .language-menu a[aria-current] { background: var(--c-panel); color: var(--c-accent); }
.menu-toggle { display: none; min-width: 44px; min-height: 44px; align-items: center; justify-content: center; background: var(--c-bg); color: var(--c-text); border: 1px solid var(--c-border); border-radius: var(--r-ctl); }
.menu-toggle svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.6; }
.nav-veil { position: fixed; inset: var(--header-h) 0 0; border: 0; padding: 0; width: 100%; background: var(--c-veil); color: var(--c-text); z-index: var(--z-veil); }
.mobile-drawer { position: absolute; top: 100%; left: 0; right: 0; z-index: var(--z-drawer); background: var(--c-bg); color: var(--c-text); border-bottom: 1px solid var(--c-border); padding: 16px var(--gutter) 24px; max-height: calc(100dvh - var(--header-h)); overflow-y: auto; overscroll-behavior: contain; }
.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-ctl); text-decoration: none; color: var(--c-text); }
.mobile-drawer a:hover, .mobile-drawer a[aria-current] { background: var(--c-panel); color: var(--c-accent); }
.mobile-drawer__languages { margin-top: 16px; padding-top: 12px; border-top: 1px solid var(--c-border); }
.mobile-drawer__languages p { margin-bottom: 6px; padding-inline: 16px; font-size: var(--fs-label); color: var(--c-muted); }
.site-footer { margin-top: 64px; padding-top: 56px; padding-bottom: 24px; background: var(--c-panel); color: var(--c-text); border-top: 1px solid var(--c-border); }
.footer-grid { display: grid; grid-template-columns: 1.3fr .8fr 1.5fr .8fr; gap: 40px; }
.footer-brand p { max-width: 300px; margin-top: 16px; color: var(--c-muted); font-size: var(--fs-sm); }
.site-footer h2 { font-size: var(--fs-sm); font-weight: var(--fw-bold); margin: 0 0 14px; letter-spacing: 0; }
.footer-links { list-style: none; margin: 0; padding: 0; }
.footer-links a { display: inline-block; padding-block: 5px; font-size: var(--fs-sm); color: var(--c-muted); text-decoration: none; overflow-wrap: anywhere; }
.footer-links a:hover { color: var(--c-accent); text-decoration: underline; }
.footer-bottom { border-top: 1px solid var(--c-border); margin-top: 36px; padding-top: 20px; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px; font-size: var(--fs-label); color: var(--c-muted); }
.footer-bottom p { margin: 0; }
.footer-legal { display: flex; flex-wrap: wrap; gap: 16px; }
.footer-legal a { color: var(--c-muted); text-decoration: none; }
.prose { min-width: 0; line-height: 1.85; }
.prose h2 { margin-top: 64px; margin-bottom: 20px; }
.prose h3 { margin-top: 36px; margin-bottom: 14px; }
.prose p, .prose ul, .prose ol { margin-bottom: 20px; }
.prose li + li { margin-top: 8px; }
.prose :not(pre) > code { background: var(--c-panel); color: var(--c-text); border-radius: var(--r-mini); padding: .1em .3em; }
.prose img { max-width: 100%; }
.reveal { opacity: 1; }
.reveal.reveal-ready { opacity: 0; transform: translateY(16px); transition: opacity var(--reveal-duration) var(--ease), transform var(--reveal-duration) var(--ease); }
.reveal.shown { opacity: 1; transform: none; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
@media (max-width: 1279px) {
  .topnav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
}
@media (min-width: 1280px) {
  .mobile-drawer, .nav-veil { display: none; }
}
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 32px; }
  .split { gap: 32px; }
}
@media (max-width: 768px) {
  :root { --section-space: 64px; }
  h1 { font-size: var(--fs-h1-mobile); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .split { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 640px) {
  :root { --gutter: 16px; --fs-h2: 24px; --fs-h3: 20px; }
  .wrap { padding-inline: var(--gutter); }
  .masthead__inner { gap: 10px; }
  .header-tools { gap: 6px; margin-left: auto; }
  .lang__full { display: none; }
  .lang__short { display: inline; }
  .lang { min-height: 44px; padding-inline: 10px; }
  .grid--2, .grid--3 { grid-template-columns: minmax(0, 1fr); }
  .card, .panel { padding: 20px; }
  .tilt, [data-tilt] { transform: none !important; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .footer-bottom { flex-direction: column; }
  .btn { min-height: 44px; padding-inline: 18px; font-size: var(--fs-nav); }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal.reveal-ready { opacity: 1; transform: none; }
}