:root {
  --bg: #FFFFFF;
  --bg-panel: #F7F7F7;
  --bg-panel-2: #EFEFEF;
  --border: #E4E4E4;
  --border-strong: #D4D4D4;
  --accent: #4E7A16;
  --accent-dark: #36560C;
  --accent-soft: rgba(78, 122, 22, 0.08);
  --accent-ring: rgba(78, 122, 22, 0.32);
  --text: #17191C;
  --text-muted: #5F6368;
  --text-faint: #8A8E93;
  --success: #2E8540;
  --warn: #B7791F;
  --error: #C2412D;
  --steel: #4A6F8E;
  --apricot: #C9813A;
  --tint-moss: #EEF3E3;
  --tint-steel: #E7EEF4;
  --tint-apricot: #F8EDE1;
  --tint-neutral: #F3F3F3;
  --surface: #FFFFFF;
  --on-accent: #FFFFFF;
  --veil: rgba(255, 255, 255, 0.36);
  --mark: rgba(23, 25, 28, 0.13);
  --scrim: rgba(23, 25, 28, 0.25);
  --clear: transparent;

  --shadow-xs: 0 1px 1px rgba(23, 25, 28, 0.04);
  --shadow-card: 0 1px 2px rgba(23, 25, 28, 0.04), 0 6px 18px -10px rgba(23, 25, 28, 0.12);
  --shadow-win: 0 1px 2px rgba(23, 25, 28, 0.05), 0 10px 22px -12px rgba(23, 25, 28, 0.18);
  --shadow-float: 0 2px 4px rgba(23, 25, 28, 0.06), 0 18px 34px -12px rgba(23, 25, 28, 0.30);
  --shadow-btn: inset 0 1px 0 rgba(255, 255, 255, 0.16), 0 1px 2px rgba(23, 25, 28, 0.14);

  --r-none: 0;
  --r-small: 3px;
  --r-field: 4px;
  --r-ctl: 6px;
  --r-win: 8px;
  --r-card: 10px;
  --r-pill: 999px;

  --font-display: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans", "Apple SD Gothic Neo", "Malgun Gothic", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans", "Apple SD Gothic Neo", "Malgun Gothic", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --fs-body: 16px;
  --fs-small: 13px;
  --fs-meta: 14px;
  --fs-brand: 17px;
  --fs-lead: clamp(30px, 2.2vw + 16px, 48px);
  --fs-h1: clamp(34px, 3vw, 48px);
  --fs-h2: 32px;
  --fs-h3: 22px;
  --fs-subtitle: 20px;
  --fs-mini: 10.5px;
  --fs-mono-mini: 10px;
  --fs-tiny: 9.5px;
  --fs-memo: 12px;
  --fs-half: 13.5px;
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;
  --weight-display: 800;
  --tracking-display: -0.02em;
  --tracking-tight: -0.01em;
  --tracking-normal: 0;
  --leading-body: 1.6;
  --leading-title: 1.15;
  --container: 1280px;
  --reading: 1120px;
  --article: 800px;
  --gutter: 32px;
  --section-gap: 96px;
  --header-height: 64px;
  --speed: .15s;
  --reveal-speed: .5s;
}

*, *::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(--fs-body);
  font-weight: var(--weight-normal);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
[hidden] { display: none !important; }
img, svg { max-width: 100%; }
img { height: auto; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, input, select, textarea { border-radius: var(--r-ctl); }
a { color: var(--accent); text-underline-offset: .2em; }
a:hover { color: var(--accent-dark); }
button:focus-visible, a:focus-visible, summary:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}
::selection { background: var(--tint-moss); color: var(--text); }
h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--text);
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 {
  font-size: var(--fs-h1);
  line-height: var(--leading-title);
  font-weight: var(--weight-display);
  letter-spacing: var(--tracking-display);
}
h2 {
  font-size: var(--fs-h2);
  line-height: 1.25;
  font-weight: var(--weight-display);
  letter-spacing: var(--tracking-display);
}
h3 { font-size: var(--fs-h3); line-height: 1.35; font-weight: var(--weight-bold); }
p { margin-top: 0; }
.word { white-space: nowrap; }
.muted { color: var(--text-muted); }
.accent-text { color: var(--accent); }
small { font-size: var(--fs-small); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
:not(pre) > code {
  padding: .1em .3em;
  border-radius: var(--r-field);
  background: var(--bg-panel);
  color: var(--text);
  font-size: .9em;
}
pre {
  min-width: 0;
  max-width: 100%;
  overflow-x: auto;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: var(--r-ctl);
  background: var(--bg-panel);
  color: var(--text);
  font-size: var(--fs-meta);
  line-height: 1.8;
  tab-size: 2;
}
pre code { overflow-wrap: normal; word-break: normal; white-space: pre; }
ul, ol { padding-left: 1.5em; }
.wrap, .prose-wrap {
  width: 100%;
  max-width: calc(var(--reading) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.prose-wrap { max-width: calc(var(--article) + var(--gutter) * 2); }
.section { padding-top: var(--section-gap); padding-bottom: var(--section-gap); }
.section-heading { margin-top: 0; margin-bottom: 28px; }
.prose { min-width: 0; overflow-wrap: break-word; line-height: 1.85; }
.prose h2 { margin-top: 2.5em; }
.prose h3 { margin-top: 1.8em; }
.prose p, .prose ul, .prose ol { margin-bottom: 1.25em; }
.prose img { display: block; }
.prose [id], section[id], article[id] { scroll-margin-top: 24px; }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.grid > *, .split > *, .footer-grid > *, .tab-workbench > * { min-width: 0; }
.split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 64px; align-items: center; }
.panel, .card {
  min-width: 0;
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--surface);
  color: var(--text);
  box-shadow: var(--shadow-card);
}
.card h3, .panel h3 { margin-top: 0; }
.card p:last-child, .panel p:last-child { margin-bottom: 0; }
.decorated, [data-hero-visual] { overflow-x: clip; }
.tilt { transform: rotate(.45deg); }
.tilt { max-height: 480px; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 48px;
  max-width: 100%;
  padding: 0 22px;
  border: 1px solid var(--clear);
  border-radius: var(--r-ctl);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  font-weight: var(--weight-bold);
  line-height: 1.3;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color var(--speed) ease, border-color var(--speed) ease, transform var(--speed) ease;
}
.btn svg {
  width: 18px; height: 18px; flex-shrink: 0;
  fill: none; stroke: currentColor; stroke-width: 1.9;
  stroke-linecap: round; stroke-linejoin: round;
}
.btn-main { background: var(--accent); color: var(--on-accent); box-shadow: var(--shadow-btn); }
.btn-main:hover, .btn-main.is-hover { background: var(--accent-dark); color: var(--on-accent); }
.btn-quiet {
  background: var(--surface); color: var(--text);
  border-color: var(--border-strong); box-shadow: var(--shadow-xs);
  font-weight: var(--weight-semibold);
}
.btn-quiet:hover, .btn-quiet.is-hover { border-color: var(--text-faint); color: var(--text); }
.btn:active, .btn.is-active { transform: translateY(1px); }
.btn.is-focus { outline: 2px solid var(--accent); outline-offset: 4px; }
.btn:disabled, .btn[aria-disabled="true"] {
  cursor: not-allowed;
  background: var(--bg-panel-2); color: var(--text-muted);
  border-color: var(--border); box-shadow: none; transform: none;
}
.cta-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; }

.masthead { position: relative; z-index: 50; background: var(--bg); color: var(--text); border-bottom: 1px solid var(--border); }
.masthead-in {
  position: relative;
  width: 100%;
  max-width: min(100%, calc(1280px + var(--gutter) * 2));
  margin: 0 auto;
  padding-inline: var(--gutter);
  height: var(--header-height);
  display: flex;
  align-items: center;
  gap: 24px;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  flex-shrink: 0; text-decoration: none; color: var(--text);
  font-family: var(--font-display); font-weight: var(--weight-display);
  font-size: var(--fs-brand); letter-spacing: var(--tracking-tight);
}
.brand:hover { color: var(--text); }
.brand-mark { width: 32px; height: 32px; display: block; flex-shrink: 0; }
.topnav { margin-left: auto; min-width: 0; }
.topnav-list {
  display: flex; align-items: center; gap: 2px;
  margin: 0; padding: 0; list-style: none;
}
.topnav-link {
  position: relative; display: inline-flex; align-items: center; gap: 6px;
  height: 36px; padding: 0 10px; border-radius: var(--r-ctl);
  font-size: var(--fs-meta); font-weight: var(--weight-medium);
  color: var(--text-muted); text-decoration: none; white-space: nowrap;
  transition: color var(--speed) ease, background-color var(--speed) ease;
}
.topnav-link svg {
  width: 16px; height: 16px; flex-shrink: 0;
  fill: none; stroke: currentColor; stroke-width: 1.6;
  stroke-linecap: round; stroke-linejoin: round;
}
.topnav-link:hover { color: var(--text); background: var(--bg-panel); }
.topnav-link[aria-current="page"] { color: var(--text); font-weight: var(--weight-semibold); }
.topnav-link[aria-current="page"] svg { color: var(--accent); }
.topnav-link[aria-current="page"]::after {
  content: ""; position: absolute; left: 10px; right: 10px; bottom: -14px;
  height: 2px; border-radius: var(--r-pill); background: var(--accent);
}
.header-tools { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.language-control { position: relative; }
.lang-pick {
  margin-left: 12px; display: inline-flex; align-items: center; gap: 6px;
  height: 34px; padding: 0 10px;
  border: 1px solid var(--border); border-radius: var(--r-ctl);
  background: var(--surface); color: var(--text);
  font-size: var(--fs-half); font-weight: var(--weight-medium);
  white-space: nowrap; list-style: none;
}
.lang-pick::-webkit-details-marker { display: none; }
.lang-pick svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 1.5; color: var(--text-muted); flex-shrink: 0; }
.lang-pick:hover { border-color: var(--border-strong); }
.lang-short { display: none; }
.lang-menu {
  position: absolute; z-index: 5; top: calc(100% + 10px); right: 0;
  width: 180px; margin: 0; padding: 6px;
  list-style: none; background: var(--surface); color: var(--text);
  border: 1px solid var(--border); border-radius: var(--r-ctl);
  box-shadow: var(--shadow-float);
}
.lang-menu a { display: flex; align-items: center; min-height: 44px; padding: 8px 12px; border-radius: var(--r-field); color: var(--text); text-decoration: none; }
.lang-menu a:hover { background: var(--bg-panel); color: var(--text); }
.lang-menu a[aria-current="true"] { color: var(--accent); font-weight: var(--weight-semibold); }
.menu-toggle {
  display: none; align-items: center; justify-content: center;
  min-width: 44px; min-height: 44px; padding: 8px;
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
}
.menu-toggle svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.6; }
.menu-veil { position: fixed; inset: var(--header-height) 0 0; z-index: 1; border: 0; border-radius: var(--r-none); background: var(--scrim); color: var(--text); }
.mobile-drawer {
  position: fixed; top: var(--header-height); left: 0; right: 0; z-index: 3;
  max-height: calc(100dvh - var(--header-height)); overflow-y: auto; overscroll-behavior: contain;
  padding: 16px var(--gutter) 24px;
  border-bottom: 1px solid var(--border); background: var(--surface); color: var(--text);
  box-shadow: var(--shadow-win);
}
.mobile-drawer ul { margin: 0; padding: 0; list-style: none; }
.mobile-drawer .topnav-link, .mobile-drawer .drawer-language {
  display: flex; width: 100%; height: auto; min-height: 44px; padding: 12px;
  color: var(--text); text-decoration: none; white-space: normal;
}
.mobile-drawer .topnav-link[aria-current="page"]::after { display: none; }
.mobile-drawer .topnav-link[aria-current="page"] { background: var(--accent-soft); color: var(--accent-dark); }
.drawer-languages { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--border); }
.mobile-drawer .drawer-language[aria-current="true"] { color: var(--accent); font-weight: var(--weight-semibold); }

.site-footer {
  margin-top: 48px; padding-top: 56px; padding-bottom: 32px;
  border-top: 1px solid var(--border); background: var(--bg); color: var(--text);
}
.footer-in { max-width: calc(var(--container) + var(--gutter) * 2); margin-inline: auto; padding-inline: var(--gutter); }
.footer-grid { display: grid; grid-template-columns: 1.2fr .9fr 1.5fr .7fr; gap: 36px; }
.footer-title { margin: 0 0 14px; font-size: var(--fs-meta); font-weight: var(--weight-bold); }
.footer-about { max-width: 300px; margin-top: 18px; color: var(--text-muted); font-size: var(--fs-meta); }
.footer-links { margin: 0; padding: 0; list-style: none; }
.footer-links a { display: inline-block; padding-top: 5px; padding-bottom: 5px; color: var(--text-muted); font-size: var(--fs-meta); text-decoration: none; overflow-wrap: anywhere; }
.footer-links a:hover { color: var(--accent); text-decoration: underline; }
.footer-bottom { margin-top: 36px; padding-top: 20px; border-top: 1px solid var(--border); color: var(--text-muted); font-size: var(--fs-small); }
.reveal { opacity: 1; transform: none; }
.reveal.reveal-pending { opacity: 0; transform: translateY(14px); transition: opacity var(--reveal-speed) ease, transform var(--reveal-speed) ease; }
.reveal.shown { opacity: 1; transform: none; }

@media (max-width: 1180px) {
  .masthead:not(.preview-head) .topnav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
}
@media (min-width: 1181px) {
  .mobile-drawer, .menu-veil { display: none !important; }
}
@media (max-width: 1180px) {
  .preview-head .masthead-in { height: auto; flex-wrap: wrap; row-gap: 4px; padding-top: 12px; padding-bottom: 6px; }
  .preview-head .topnav { order: 3; width: 100%; margin-left: 0; overflow-x: auto; scrollbar-width: thin; }
  .preview-head .topnav-link[aria-current="page"]::after { bottom: 0; }
}
@media (max-width: 768px) {
  :root { --gutter: 16px; --section-gap: 56px; --fs-h1: clamp(24px, 6.4vw, 30px); --fs-h2: 24px; --fs-h3: 20px; }
  .word { white-space: normal; overflow-wrap: anywhere; }
  .grid, .split { grid-template-columns: minmax(0, 1fr); }
  .split { gap: 32px; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; }
  .masthead-in { gap: 8px; }
  .brand { font-size: var(--fs-body); gap: 8px; flex-shrink: 1; min-width: 0; }
  .brand > span { min-width: 0; overflow-wrap: anywhere; }
  .lang-pick { margin-left: 0; }
  .btn { height: 46px; padding-inline: 18px; font-size: var(--fs-meta); }
}
@media (max-width: 640px) {
  .tilt, [data-tilt] { transform: none; }
  .panel, .card { padding: 20px; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .lang-pick { min-height: 44px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .reveal.reveal-pending { opacity: 1; transform: none; }
}