:root {
  --bg: #ffffff;
  --bg-panel: #f7f7f7;
  --bg-panel-2: #efefef;
  --border: #e6e6e6;
  --grid-line: #ededed;
  --accent: #33607a;
  --accent-dark: #1f4256;
  --apricot: #e9a06b;
  --text: #0d0d0d;
  --text-muted: #6b6b6b;
  --text-faint: #a6a6a6;
  --ink: #0d0d0d;
  --ink-hover: #262626;
  --on-ink: #ffffff;
  --board-word: #ffffff;
  --mask: #000000;
  --clear: transparent;
  --success: #2f7d5b;
  --warn: #b7791f;
  --error: #b3403a;
  --shadow-hair: 0 1px 2px rgba(13, 13, 13, 0.04);
  --shadow-float: 0 12px 40px rgba(13, 13, 13, 0.05);
  --shadow-sheet: 0 1px 2px rgba(13, 13, 13, 0.03);
  --r-card: 28px;
  --r-frame: 36px;
  --r-pill: 999px;
  --r-icon: 11px;
  --r-icon-sm: 7px;
  --r-shot: 10px;
  --r-small: 4px;
  --r-circle: 50%;
  --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-strong: 600;
  --tracking-title: -0.02em;
  --text-base: 16px;
  --text-small: 14px;
  --text-caption: 12.5px;
  --h1-size: clamp(34px, 2.2vw + 16px, 48px);
  --h2-size: clamp(26px, 3vw, 36px);
  --h3-size: 22px;
  --nav-h: 64px;
  --peek: 72px;
  --gutter: 48px;
  --content-max: 1184px;
  --header-max: 1280px;
  --reading-max: 800px;
  --section-space: 160px;
  --cycle: 16s;
  --ease: cubic-bezier(.2, .7, .2, 1);
  --duration-fast: .2s;
  --duration-reveal: .65s;
  --board-angle: 118deg;
}

*, *::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: var(--text-base);
  font-weight: var(--weight-normal);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
main, section, article, aside, nav, div, figure { min-width: 0; }
img { max-width: 100%; }
svg { flex-shrink: 0; vertical-align: middle; }
a { color: inherit; text-underline-offset: .22em; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, a { -webkit-tap-highlight-color: var(--clear); }
button:disabled { cursor: not-allowed; }
[hidden] { display: none !important; }
:focus-visible {
  outline: 2px solid var(--text);
  outline-offset: 4px;
}
::selection { background: var(--bg-panel-2); color: var(--text); }
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: var(--weight-normal);
  letter-spacing: var(--tracking-title);
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { margin: 0 0 26px; font-size: var(--h1-size); line-height: 1.16; }
h2 { margin: 0 0 20px; font-size: var(--h2-size); line-height: 1.25; }
h3 { margin: 0 0 12px; font-size: var(--h3-size); line-height: 1.4; }
p { margin: 0 0 20px; }
strong { font-weight: var(--weight-medium); }
small { font-size: var(--text-caption); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--bg-panel);
  color: var(--text);
  font-size: var(--text-small);
  line-height: 1.8;
  overscroll-behavior-inline: contain;
}
pre code { white-space: pre; overflow-wrap: normal; word-break: normal; }
hr { margin-block: 40px; border: 0; border-top: 1px solid var(--border); }
.nowrap { white-space: nowrap; }
h2 .nowrap { white-space: normal; }
.muted { color: var(--text-muted); }
.mono { font-family: var(--font-mono); }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: fixed;
  top: 8px;
  left: var(--gutter);
  z-index: 100;
  padding: 10px 20px;
  border-radius: var(--r-pill);
  background: var(--ink);
  color: var(--on-ink);
  transform: translateY(-160%);
}
.skip-link:focus { transform: none; }
.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); }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.section + .section { padding-top: 0; }
.section-head { max-width: 760px; margin-bottom: 40px; }
.eyebrow { margin-bottom: 16px; color: var(--text-muted); font-size: var(--text-small); }
.prose { min-width: 0; line-height: 1.85; }
.prose h2 { margin-top: 72px; }
.prose h3 { margin-top: 36px; }
.prose :is(ul, ol) { padding-left: 1.5em; }
.prose li { margin-block: 10px; }
.prose a { text-decoration-thickness: 1px; }
.prose img { height: auto; }
.grid-two { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.grid-three { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.flow > * + * { margin-top: 24px; }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.card, .panel {
  min-width: 0;
  padding: 32px;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-hair);
}
.panel { background: var(--bg-panel); color: var(--text); }
.card > :last-child, .panel > :last-child { margin-bottom: 0; }
.card-link { display: block; text-decoration: none; }
.card-link:hover { box-shadow: var(--shadow-hair), var(--shadow-float); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  max-width: 100%;
  padding: 10px 24px;
  border: 1px solid var(--clear);
  border-radius: var(--r-pill);
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: var(--weight-medium);
  line-height: 1.5;
  text-align: center;
  text-decoration: none;
  transition: transform var(--duration-fast) var(--ease), opacity var(--duration-fast) var(--ease);
}
.btn:hover { transform: translateY(-1px); }
.btn svg { width: 16px; height: 16px; }
.btn-dark { background: var(--ink); color: var(--on-ink); }
.btn-dark:hover, .btn-dark.is-hover { background: var(--ink-hover); color: var(--on-ink); }
.btn-ghost {
  background: var(--bg);
  color: var(--text);
  border-color: var(--border);
  box-shadow: var(--shadow-hair);
}
.btn-ghost:hover { background: var(--bg-panel); color: var(--text); }
.btn-sm { min-height: 40px; padding: 8px 18px; font-size: var(--text-small); }
.btn:disabled, .btn[aria-disabled="true"] { opacity: .45; transform: none; pointer-events: none; }
.btn.is-focus { outline: 2px solid var(--text); outline-offset: 4px; }
.apple { width: 16px; height: 16px; margin-top: -2px; }

.topbar {
  position: relative;
  z-index: 40;
  height: var(--nav-h);
  background: var(--bg);
  color: var(--text);
}
.topbar-inner {
  position: relative;
  width: 100%;
  max-width: min(100%, calc(var(--header-max) + var(--gutter) * 2));
  height: 100%;
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  text-decoration: none;
}
.brand-mark {
  display: block;
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  border: 1px solid var(--border);
  border-radius: var(--r-icon-sm);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-hair);
}
.brand-name { font-size: 15px; font-weight: var(--weight-medium); letter-spacing: -.01em; }
.mainnav { min-width: 0; margin-left: 40px; }
.mainnav ul {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 2px;
}
.mainnav a {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 36px;
  padding: 6px 12px;
  border-radius: var(--r-pill);
  font-size: var(--text-small);
  white-space: nowrap;
  text-decoration: none;
}
.mainnav svg { width: 16px; height: 16px; color: var(--text-muted); }
.mainnav a:hover, .mainnav a[aria-current="page"] { background: var(--bg-panel); color: var(--text); }
.mainnav a[aria-current="page"] svg { color: var(--text); }
.topbar-tools { display: flex; align-items: center; gap: 10px; margin-left: auto; flex-shrink: 0; }
.language-control { position: relative; }
.lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 40px;
  padding: 8px 16px;
  border: 0;
  border-radius: var(--r-pill);
  background: var(--bg-panel);
  color: var(--text);
  font-size: var(--text-small);
  text-decoration: none;
}
.lang svg { width: 16px; height: 16px; color: var(--text-muted); }
.lang-short { display: none; }
.lang-caret { color: var(--text-muted); font-size: 11px; }
.lang-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  width: 200px;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-hair), var(--shadow-float);
}
.lang-menu a { display: flex; align-items: center; min-height: 44px; padding: 10px 16px; border-radius: var(--r-pill); text-decoration: none; }
.lang-menu a:hover, .lang-menu a[aria-current="true"] { background: var(--bg-panel); color: var(--text); }
.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--bg);
  color: var(--text);
}
.menu-toggle svg { width: 20px; height: 20px; }
.mobile-nav {
  position: absolute;
  top: var(--nav-h);
  left: 0;
  right: 0;
  z-index: 42;
  max-height: calc(100vh - var(--nav-h));
  max-height: calc(100dvh - var(--nav-h));
  padding: 16px var(--gutter) 24px;
  overflow-y: auto;
  overscroll-behavior: contain;
  background: var(--bg);
  color: var(--text);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-float);
}
.mobile-nav ul { padding: 0; margin: 0; list-style: none; }
.mobile-nav a {
  display: flex;
  width: 100%;
  align-items: center;
  gap: 12px;
  min-height: 48px;
  padding: 12px 16px;
  text-decoration: none;
  border-radius: var(--r-icon);
}
.mobile-nav a svg { width: 18px; height: 18px; }
.mobile-nav a:hover, .mobile-nav a[aria-current] { background: var(--bg-panel); color: var(--text); }
.mobile-languages { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--border); }
.mobile-languages p { padding-inline: 16px; margin-bottom: 8px; color: var(--text-muted); font-size: var(--text-small); }
.nav-veil {
  position: fixed;
  inset: var(--nav-h) 0 0;
  z-index: 39;
  border: 0;
  background: var(--bg-panel-2);
  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: 1.4fr 1fr 1.3fr 1fr; gap: 40px; }
.footer-brand p { max-width: 290px; margin-top: 20px; font-size: var(--text-small); color: var(--text-muted); }
.footer-title { font-size: var(--text-small); margin: 0 0 18px; }
.footer-links { margin: 0; padding: 0; list-style: none; }
.footer-links a { display: inline-block; padding-block: 6px; font-size: var(--text-small); color: var(--text-muted); text-decoration: none; overflow-wrap: anywhere; }
.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: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: var(--text-caption);
  color: var(--text-muted);
}
.footer-bottom p { margin: 0; }
.footer-legal { display: flex; flex-wrap: wrap; gap: 20px; }

.reveal { opacity: 1; transform: none; }
html.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(16px); }
html.reveal-ready .reveal {
  transition: opacity var(--duration-reveal) var(--ease), transform var(--duration-reveal) var(--ease);
}
.reveal.shown { opacity: 1; transform: none; }
.decorated, .hero, .board { overflow-x: clip; }

@media (max-width: 1279px) {
  .mainnav { display: none; }
  .menu-toggle { display: inline-flex; }
  .topbar-tools { margin-left: auto; }
}
@media (min-width: 1280px) {
  .mobile-nav, .nav-veil { display: none !important; }
}
@media (max-width: 960px) {
  :root { --gutter: 24px; --section-space: 112px; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-three { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 768px) {
  :root { --h1-size: clamp(24px, 4vw, 30px); }
}
@media (max-width: 640px) {
  :root { --gutter: 20px; --section-space: 96px; }
  .grid-two, .grid-three { grid-template-columns: minmax(0, 1fr); }
  .card, .panel { padding: 24px; }
  .brand { min-width: 0; flex-shrink: 1; margin-right: 10px; }
  .brand-name { min-width: 0; font-size: 14px; overflow-wrap: anywhere; line-height: 1.3; }
  .topbar-tools { gap: 6px; margin-left: auto; }
  .topbar-tools > .btn-sm { display: none; }
  .lang { padding-inline: 12px; }
  .lang-label { display: none; }
  .lang-short { display: inline; }
  .footer-grid { gap: 32px 20px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom { margin-top: 36px; }
  .tilt, [data-tilt] { transform: none !important; }
  pre { padding: 18px; }
}
@media (max-width: 360px) {
  :root { --gutter: 16px; }
  .brand-name { max-width: 154px; font-size: 12px; }
  .lang svg { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  html.reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
  .btn:hover { transform: none; }
}