:root {
  --bg: #ffffff;
  --bg-panel: #f3f3f1;
  --bg-panel-2: #0b4a37;
  --border: #e3e4e1;
  --accent: #0e5e46;
  --accent-dark: #073d2e;
  --text: #15181a;
  --text-muted: #5a605d;
  --success: #1fb889;
  --warn: #c4860f;
  --error: #cf4537;
  --cta: #22cdb4;
  --cta-hover: #1cbca5;
  --cta-soft: rgba(34, 205, 180, .2);
  --lime: #d4f25a;
  --accent-soft: rgba(14, 94, 70, .08);
  --ink: #1a1b1c;
  --white: #ffffff;
  --code-gray: #68716c;
  --on-dark: #ffffff;
  --on-dark-muted: rgba(255, 255, 255, .76);
  --on-dark-line: rgba(255, 255, 255, .12);
  --ring-line: rgba(255, 255, 255, .13);
  --ring-dash: rgba(255, 255, 255, .2);
  --ring-dot: rgba(255, 255, 255, .7);
  --screen-arc: rgba(255, 255, 255, .4);
  --screen-arc-2: rgba(255, 255, 255, .24);
  --glass-hi: rgba(255, 255, 255, .22);
  --glass-lo: rgba(255, 255, 255, 0);
  --edge-hi: rgba(255, 255, 255, .6);
  --birch-hi: #f3e7d1;
  --birch: #e3cda8;
  --birch-mid: #d4b98e;
  --birch-lo: #ba9c6e;
  --birch-grain: #a98b5f;
  --ti-hi: #d0d4d2;
  --ti: #9ea4a1;
  --ti-lo: #5e6462;
  --bezel: #0b0c0d;
  --floor-shadow: #021c14;
  --veil: rgba(2, 28, 20, .35);
  --clear: transparent;
  --shadow-color: rgba(14, 94, 70, .22);
  --shadow-lift: 0 18px 40px -18px var(--shadow-color);
  --shadow-float: 0 1px 2px rgba(2, 28, 20, .12), 0 22px 44px -18px rgba(2, 28, 20, .55);
  --shadow-fab: 0 1px 2px rgba(7, 61, 46, .16), 0 18px 40px -18px var(--shadow-color);
  --r-section: 40px;
  --r-detail: 32px;
  --r-float: 20px;
  --r-btn: 12px;
  --r-shot: 10px;
  --r-pill: 999px;
  --r-mark: .14em;
  --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-semibold: 600;
  --weight-bold: 700;
  --size-body: 16px;
  --size-small: 14px;
  --size-caption: 12.5px;
  --size-h1: clamp(34px, 3.4vw, 48px);
  --size-h2: clamp(26px, 3vw, 36px);
  --size-h3: 22px;
  --tracking-title: -.02em;
  --header-h: 76px;
  --gutter: clamp(20px, 5vw, 72px);
  --wrap-max: 1440px;
  --reading-max: 820px;
  --stage-w: min(46vw, 680px);
  --stage-h: clamp(540px, calc(100vh - 236px), 624px);
  --space-section: 80px;
  --speed: .2s;
  --ease: cubic-bezier(.2, .7, .2, 1);
}
*, *::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(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--size-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img, svg { max-width: 100%; }
img { height: auto; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, a { -webkit-tap-highlight-color: var(--cta-soft); }
button { color: var(--text); }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: .22em; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
[hidden] { display: none !important; }
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  letter-spacing: var(--tracking-title);
  line-height: 1.2;
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { font-size: var(--size-h1); }
h2 { font-size: var(--size-h2); }
h3 { font-size: var(--size-h3); }
p { margin-block: 0 1.2em; }
h2, h3, h4 { margin-block: 1.6em .65em; }
h1 { margin-block: 0 .7em; }
strong { font-weight: var(--weight-semibold); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: var(--r-float);
  background: var(--bg-panel);
  color: var(--text);
  font-size: var(--size-small);
  line-height: 1.8;
  tab-size: 2;
}
pre code { overflow-wrap: normal; word-break: normal; white-space: pre; }
blockquote { margin-inline: 0; }
:target { scroll-margin-top: 24px; }
.wrap {
  width: 100%;
  max-width: var(--wrap-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { max-width: calc(var(--reading-max) + var(--gutter) * 2); }
.section { padding-top: var(--space-section); padding-bottom: var(--space-section); }
.section-muted { background: var(--bg-panel); color: var(--text); }
.section-heading { margin-top: 0; }
.grid-two { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; }
.grid-two > *, .hero-grid > *, .footer-grid > *, .feature-layout > * { min-width: 0; }
.prose { min-width: 0; line-height: 1.85; }
.prose > :first-child { margin-top: 0; }
.prose a { text-decoration: underline; text-underline-offset: .2em; }
.prose li { margin-block: .45em; }
.prose :not(pre) > code {
  padding: .12em .3em;
  border-radius: var(--r-mark);
  background: var(--bg-panel);
  color: var(--accent-dark);
}
.muted { color: var(--text-muted); }
.small { font-size: var(--size-small); }
.mono { font-family: var(--font-mono); }
.keep { 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;
}
.card, .panel {
  min-width: 0;
  padding: 32px;
  border: 1px solid var(--border);
  border-radius: var(--r-detail);
  background: var(--bg);
  color: var(--text);
}
.panel { background: var(--bg-panel); color: var(--text); }
.card > :first-child, .panel > :first-child { margin-top: 0; }
.card > :last-child, .panel > :last-child { margin-bottom: 0; }
.card-dark { background: var(--ink); color: var(--on-dark); border-color: var(--ink); }
.card-green { background: var(--bg-panel-2); color: var(--on-dark); border-color: var(--bg-panel-2); }
.card-dark p, .card-green p { color: var(--on-dark-muted); }
.card-dark a:not(.btn), .card-green a:not(.btn) { color: var(--on-dark); }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  padding: 12px 24px;
  border: 1px solid var(--clear);
  border-radius: var(--r-btn);
  font-family: var(--font-body);
  font-size: var(--size-body);
  font-weight: var(--weight-semibold);
  letter-spacing: -.005em;
  line-height: 1.45;
  text-align: center;
  transition: background-color var(--speed) ease, transform var(--speed) ease;
}
.btn svg { width: 18px; height: 18px; flex-shrink: 0; }
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--cta); color: var(--accent-dark); box-shadow: var(--shadow-lift); }
.btn-primary:hover, .btn-primary.is-hover { background: var(--cta-hover); color: var(--accent-dark); transform: translateY(-1px); }
.btn-secondary { background: var(--bg); color: var(--accent); border: 1.5px solid var(--accent); }
.btn-secondary:hover, .btn-secondary.is-hover { background: var(--accent-soft); color: var(--accent); }
.btn:active, .btn.is-active { transform: translateY(1px); }
.btn:disabled { background: var(--bg-panel); color: var(--text-muted); border-color: var(--border); box-shadow: none; cursor: not-allowed; }
.btn.is-focus { outline: 3px solid var(--accent); outline-offset: 4px; }
.topbar { position: relative; z-index: 60; background: var(--bg); color: var(--text); border-bottom: 1px solid var(--border); }
.header-shell {
  width: 100%;
  max-width: min(100%, calc(1280px + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.topbar-row { display: flex; align-items: center; gap: 40px; height: var(--header-h); }
.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--text); flex-shrink: 0; }
.brand:hover { text-decoration: none; }
.brand-mark { display: block; width: 36px; height: 36px; flex-shrink: 0; border-radius: var(--r-shot); background: var(--bg-panel); border: 1px solid var(--border); }
.brand-name { font-family: var(--font-display); font-weight: var(--weight-bold); font-size: var(--size-body); letter-spacing: -.01em; }
.tabs { flex: 1; min-width: 0; height: 100%; }
.tabs ul { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: 2px; height: 100%; }
.tabs li { height: 100%; }
.tabs a {
  position: relative;
  display: flex;
  align-items: center;
  height: 100%;
  padding-inline: 15px;
  color: var(--text-muted);
  font-size: 15px;
  font-weight: var(--weight-medium);
  white-space: nowrap;
}
.tabs a:hover { color: var(--text); text-decoration: none; }
.tabs a[aria-current="page"] { color: var(--text); font-weight: var(--weight-semibold); }
.tabs a[aria-current="page"]::after {
  content: "";
  position: absolute;
  inset-inline: 15px;
  bottom: -1px;
  height: 3px;
  background: var(--accent);
  border-radius: var(--r-pill);
}
.header-tools { display: flex; align-items: center; gap: 10px; flex-shrink: 0; margin-left: auto; }
.language-control { position: relative; }
.lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 40px;
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: var(--r-btn);
  background: var(--bg);
  color: var(--text);
  font-size: var(--size-small);
  font-weight: var(--weight-medium);
  white-space: nowrap;
}
.lang svg { width: 16px; height: 16px; color: var(--text-muted); flex-shrink: 0; }
.lang-short { display: none; }
.language-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  width: 190px;
  margin: 0;
  padding: 8px;
  list-style: none;
  border: 1px solid var(--border);
  border-radius: var(--r-float);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-lift);
}
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 10px 14px; border-radius: var(--r-btn); color: var(--text); }
.language-menu a:hover, .language-menu a[aria-current] { background: var(--accent-soft); color: var(--accent); text-decoration: none; }
.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-btn); background: var(--bg); color: var(--text); }
.menu-toggle svg { width: 22px; height: 22px; }
.mobile-nav { display: none; }
.nav-veil { position: fixed; inset: var(--header-h) 0 0; z-index: 40; border: 0; background: var(--veil); color: var(--text); }
.site-footer { padding-top: 64px; padding-bottom: 100px; background: var(--bg-panel); color: var(--text); border-top: 1px solid var(--border); }
.footer-grid { display: grid; grid-template-columns: 1.3fr .7fr 1.2fr .65fr; gap: 36px; }
.footer-brand p { max-width: 30em; margin-top: 20px; color: var(--text-muted); font-size: var(--size-small); }
.footer-heading { margin: 0 0 16px; font-size: var(--size-body); }
.footer-links { margin: 0; padding: 0; list-style: none; }
.footer-links a { display: inline-block; padding-block: 5px; color: var(--text-muted); font-size: var(--size-small); overflow-wrap: anywhere; }
.footer-bottom { display: flex; flex-wrap: wrap; gap: 12px 28px; margin-top: 40px; padding-top: 22px; border-top: 1px solid var(--border); color: var(--text-muted); font-size: var(--size-caption); }
.footer-bottom a { color: var(--text-muted); }
.reveal { opacity: 1; transform: none; }
.reveal-ready .reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
.reveal-ready .reveal.shown { opacity: 1; transform: none; }
@media (max-width: 1199px) {
  .topbar-row { gap: 24px; }
  .desktop-nav { display: none; }
  .menu-toggle { display: inline-flex; }
  .header-tools { margin-left: auto; }
  .mobile-nav {
    position: absolute;
    top: 100%;
    inset-inline: 0;
    display: block;
    max-height: calc(100dvh - var(--header-h));
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: 16px var(--gutter) 24px;
    border-bottom: 1px solid var(--border);
    background: var(--bg);
    color: var(--text);
    box-shadow: var(--shadow-lift);
  }
  .mobile-nav ul { margin: 0; padding: 0; list-style: none; }
  .mobile-nav a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 12px 16px; color: var(--text); border-radius: var(--r-btn); }
  .mobile-nav a:hover, .mobile-nav a[aria-current] { background: var(--accent-soft); color: var(--accent); text-decoration: none; }
  .mobile-languages { margin-top: 14px !important; padding-top: 14px !important; border-top: 1px solid var(--border); }
}
@media (max-width: 960px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 768px) {
  :root { --size-h1: clamp(24px, 7vw, 30px); --space-section: 52px; }
  .grid-two { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 640px) {
  :root { --gutter: 20px; --header-h: 72px; }
  .topbar-row { gap: 12px; }
  .brand { gap: 8px; min-width: 0; flex-shrink: 1; }
  .brand-name { font-size: 13px; line-height: 1.4; max-width: 11em; }
  .brand-mark { width: 32px; height: 32px; }
  .header-tools { gap: 6px; margin-left: auto; }
  .lang { min-height: 44px; padding-inline: 10px; }
  .lang-full, .lang > svg { display: none; }
  .lang-short { display: inline; }
  .card, .panel { padding: 24px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .tilt, [data-tilt] { transform: none !important; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal-ready .reveal { opacity: 1; transform: none; }
}