:root {
  --bg: #f5f8ff;
  --bg-panel: #ffffff;
  --bg-panel-2: #edf1f9;
  --border: #d9e0ec;
  --border-faint: #e6ebf3;
  --accent: #1d6ad4;
  --accent-dark: #134c9e;
  --text: #1f2a37;
  --text-muted: #5a6678;
  --success: #1f8a4c;
  --warn: #b7791f;
  --error: #c8372d;
  --highlight: #ffe45c;
  --clear: transparent;
  --accent-wash: rgba(29, 106, 212, 0.07);
  --grid-line: rgba(29, 106, 212, 0.075);
  --veil: rgba(31, 42, 55, 0.28);
  --shadow-board: 0 24px 60px rgba(31, 42, 55, 0.08), 0 2px 6px rgba(31, 42, 55, 0.04);
  --shadow-raise: 0 10px 24px rgba(31, 42, 55, 0.07), 0 1px 2px rgba(31, 42, 55, 0.05);
  --shadow-soft: 0 1px 2px rgba(31, 42, 55, 0.06);
  --shadow-btn: 0 8px 18px rgba(29, 106, 212, 0.22), inset 0 -1px 0 rgba(19, 76, 158, 0.55);
  --radius-card: 6px;
  --radius-btn: 6px;
  --radius-pill: 999px;
  --radius-mini: 4px;
  --radius-mark: 8px;
  --radius-shot: 10px;
  --radius-tab: 3px;
  --font-display: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC", "PingFang TC", "Hiragino Sans", "Apple SD Gothic Neo", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC", "PingFang TC", "Hiragino Sans", "Apple SD Gothic Neo", "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;
  --weight-display: 800;
  --size-tiny: 11.5px;
  --size-caption: 12px;
  --size-small: 13px;
  --size-label: 14px;
  --size-nav: 15px;
  --size-body: 16px;
  --size-reading: 17px;
  --size-brand: 17px;
  --size-h1: clamp(34px, 2.2vw + 16px, 48px);
  --size-h2: clamp(26px, 2.5vw, 32px);
  --size-h3: 24px;
  --size-mobile-title: 30px;
  --tracking-title: -0.02em;
  --tracking-brand: -0.01em;
  --leading-body: 1.6;
  --leading-title: 1.1;
  --leading-reading: 1.85;
  --wrap: 1328px;
  --header-wrap: 1328px;
  --reading-wrap: 800px;
  --gutter: 56px;
  --nav-h: 72px;
  --lead-w: 500px;
  --col-gap: 64px;
  --section-space: 160px;
  --duration-fast: 160ms;
  --duration-reveal: 500ms;
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
}
*, *::before, *::after { box-sizing: border-box; }
html { color-scheme: light; scroll-behavior: smooth; scroll-padding-top: 28px; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--size-body);
  font-weight: var(--weight-normal);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
[hidden] { display: none !important; }
img, svg { max-width: 100%; }
img { vertical-align: middle; }
button, input, select, textarea { font: inherit; }
button, summary, a { -webkit-tap-highlight-color: var(--accent-wash); }
button { cursor: pointer; }
a { color: var(--accent); text-underline-offset: 4px; }
a:hover { color: var(--accent-dark); }
a:focus-visible, button:focus-visible, summary:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: var(--radius-mini);
}
button:disabled { cursor: not-allowed; }
h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: var(--weight-display);
  letter-spacing: var(--tracking-title);
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { margin: 0 0 24px; font-size: var(--size-h1); line-height: var(--leading-title); }
h2 { margin: 0 0 24px; font-size: var(--size-h2); line-height: 1.2; }
h3 { margin: 0 0 16px; font-size: var(--size-h3); line-height: 1.3; }
p { margin: 0 0 24px; }
strong { font-weight: var(--weight-bold); }
small, .muted { color: var(--text-muted); }
code, pre, .mono { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  min-width: 0;
  margin: 24px 0;
  padding: 20px;
  overflow-x: auto;
  background: var(--bg-panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-mini);
  font-size: var(--size-label);
  line-height: 1.75;
  tab-size: 2;
}
pre code { overflow-wrap: normal; word-break: normal; white-space: pre; }
blockquote { margin-inline: 0; }
hr { border: 0; border-top: 1px solid var(--border); margin: 32px 0; }
mark { background: var(--clear); color: inherit; }
.hl, .hl-strong {
  padding-inline: 2px;
  background-image: linear-gradient(to bottom, var(--clear) 58%, var(--highlight) 58%, var(--highlight) 94%, var(--clear) 94%);
  -webkit-box-decoration-break: clone;
  box-decoration-break: clone;
}
.hl-strong {
  padding-inline: 3px;
  background-image: linear-gradient(to bottom, var(--clear) 56%, var(--highlight) 56%, var(--highlight) 90%, var(--clear) 90%);
}
.keep { white-space: nowrap; }
.wrap, .header-wrap, .reading-wrap {
  width: 100%;
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.wrap { max-width: calc(var(--wrap) + var(--gutter) * 2); }
.header-wrap { max-width: min(100%, calc(var(--header-wrap) + var(--gutter) * 2)); }
.reading-wrap { max-width: calc(var(--reading-wrap) + var(--gutter) * 2); }
.section { padding-top: var(--section-space); padding-bottom: 0; }
.section:last-child { padding-bottom: var(--section-space); }
.grid-two { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.grid-two > *, .hero-grid > *, .letters-grid > *, .footer-grid > *, .prose, .prose * { min-width: 0; }
.stack > * + * { margin-top: 24px; }
.prose { font-size: var(--size-reading); line-height: var(--leading-reading); }
.prose h2 { margin-top: 64px; }
.prose h3 { margin-top: 36px; }
.prose li + li { margin-top: 8px; }
.prose a { overflow-wrap: anywhere; }
.prose :first-child { margin-top: 0; }
.card, .panel {
  padding: 28px;
  background: var(--bg-panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-board);
  min-width: 0;
}
.card > :last-child, .panel > :last-child { margin-bottom: 0; }
.card-title { font-size: var(--size-h3); }
.eyebrow { font-size: var(--size-small); font-weight: var(--weight-bold); color: var(--accent); }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; align-items: center; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  max-width: 100%;
  padding: 10px 22px;
  border: 1px solid var(--clear);
  border-radius: var(--radius-btn);
  font-size: var(--size-body);
  line-height: 1.5;
  font-weight: var(--weight-bold);
  text-align: center;
  text-decoration: none;
  transition: background-color var(--duration-fast) ease, border-color var(--duration-fast) ease;
}
.btn svg { width: 18px; height: 18px; flex-shrink: 0; }
.btn-solid { background: var(--accent); color: var(--bg-panel); box-shadow: var(--shadow-btn); }
.btn-solid:hover, .btn-solid:active { background: var(--accent-dark); color: var(--bg-panel); }
.btn-line {
  background: var(--bg-panel);
  color: var(--accent);
  border-color: var(--border);
  box-shadow: var(--shadow-soft);
}
.btn-line:hover { border-color: var(--accent); color: var(--accent-dark); }
.btn:disabled, .btn[aria-disabled="true"] {
  background: var(--bg-panel-2);
  color: var(--text-muted);
  border-color: var(--border);
  box-shadow: none;
}
.btn-arrow { font-weight: var(--weight-normal); }
.masthead { position: relative; z-index: 40; background: var(--bg); color: var(--text); border-bottom: 1px solid var(--border); }
.masthead-row { display: flex; align-items: center; gap: 40px; min-height: var(--nav-h); }
.brand { display: inline-flex; align-items: center; gap: 12px; flex-shrink: 0; text-decoration: none; color: var(--text); }
.brand:hover { color: var(--text); }
.brand-mark {
  display: block;
  width: 34px;
  height: 34px;
  flex-shrink: 0;
  border-radius: var(--radius-pill);
}
.brand-placeholder {
  border-radius: var(--radius-mark);
  border: 1px solid var(--border);
  background: linear-gradient(145deg, var(--bg-panel), var(--bg-panel-2));
  color: var(--text);
  box-shadow: inset 0 0 0 4px var(--bg-panel), var(--shadow-soft);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-size: var(--size-brand); font-weight: var(--weight-display); letter-spacing: var(--tracking-brand); }
.brand-sub { font-size: var(--size-caption); color: var(--text-muted); }
.desktop-nav { min-width: 0; margin-left: auto; }
.tabbar {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 30px;
  height: var(--nav-h);
}
.tabbar li { height: 100%; }
.tabbar a {
  position: relative;
  display: flex;
  align-items: center;
  height: 100%;
  color: var(--text-muted);
  font-size: var(--size-nav);
  font-weight: var(--weight-medium);
  text-decoration: none;
  white-space: nowrap;
}
.tabbar a::after {
  content: "";
  position: absolute;
  inset: auto 0 -1px;
  height: 3px;
  border-radius: var(--radius-tab) var(--radius-tab) 0 0;
  background: var(--accent);
  color: var(--bg-panel);
  transform: scaleX(0);
  transform-origin: left center;
}
.tabbar a:hover, .tabbar a[aria-current="page"] { color: var(--text); }
.tabbar a[aria-current="page"] { font-weight: var(--weight-bold); }
.tabbar a:hover::after, .tabbar a[aria-current="page"]::after { transform: scaleX(1); }
.header-tools { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.lang-wrap { position: relative; }
.lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 34px;
  padding: 5px 13px;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  background: var(--bg-panel);
  color: var(--text);
  font-size: var(--size-label);
  white-space: nowrap;
}
.lang svg { width: 15px; height: 15px; color: var(--text-muted); flex-shrink: 0; }
.lang-caret { font-size: var(--size-tiny); color: var(--text-muted); }
.lang-short { display: none; }
.lang-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  min-width: 180px;
  padding: 8px;
  background: var(--bg-panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-board);
  z-index: 5;
}
.lang-menu a { display: flex; align-items: center; min-height: 44px; padding: 8px 12px; text-decoration: none; }
.lang-menu a:hover, .lang-menu a[aria-current="true"] { background: var(--bg-panel-2); color: var(--accent-dark); }
.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius-btn);
  background: var(--bg-panel);
  color: var(--text);
}
.menu-toggle svg { width: 22px; height: 22px; flex-shrink: 0; }
.nav-drawer { display: none; }
.nav-veil {
  position: fixed;
  inset: var(--nav-h) 0 0;
  z-index: 1;
  border: 0;
  background: var(--veil);
  color: var(--text);
  cursor: default;
}
.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -100px;
  z-index: 100;
  padding: 12px 16px;
  background: var(--bg-panel);
  color: var(--accent-dark);
  border: 1px solid var(--border);
}
.skip-link:focus { top: 8px; }
.site-footer { margin-top: var(--section-space); padding-top: 56px; padding-bottom: 32px; border-top: 1px solid var(--border); }
.footer-grid { display: grid; grid-template-columns: 1.35fr 0.7fr 1fr; gap: 64px; }
.footer-brand p { margin-top: 20px; max-width: 30em; font-size: var(--size-label); color: var(--text-muted); }
.footer-title { margin-bottom: 16px; font-size: var(--size-body); font-weight: var(--weight-bold); }
.footer-links { list-style: none; margin: 0; padding: 0; }
.footer-links a { display: inline-block; padding-top: 6px; padding-bottom: 6px; }
.footer-languages { display: flex; flex-wrap: wrap; gap: 8px 24px; margin-top: 32px; }
.footer-languages a { padding-top: 8px; padding-bottom: 8px; }
.footer-bottom { display: flex; flex-wrap: wrap; gap: 12px 24px; margin-top: 24px; padding-top: 24px; border-top: 1px solid var(--border); font-size: var(--size-small); color: var(--text-muted); }
.footer-bottom p { margin: 0; }
.reveal { opacity: 1; }
.reveal-ready .reveal { opacity: 0; transform: translateY(12px); transition: opacity var(--duration-reveal) var(--ease), transform var(--duration-reveal) var(--ease); }
.reveal-ready .reveal.shown { opacity: 1; transform: none; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; border: 0; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.hero, .decorated-section { position: relative; overflow-x: clip; }
@media (max-width: 1279px) {
  .desktop-nav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
  .masthead-row { gap: 20px; }
  .nav-drawer:not([hidden]) {
    display: block;
    position: fixed;
    top: var(--nav-h);
    inset-inline: 0;
    z-index: 2;
    max-height: calc(100dvh - var(--nav-h));
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: 16px var(--gutter) 28px;
    background: var(--bg-panel);
    color: var(--text);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-board);
  }
  .nav-drawer ul { list-style: none; margin: 0; padding: 0; }
  .nav-drawer a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 12px 8px; text-decoration: none; }
  .nav-drawer a[aria-current] { color: var(--accent-dark); text-decoration: underline; font-weight: var(--weight-bold); }
  .drawer-languages { border-top: 1px solid var(--border); margin-top: 16px; padding-top: 16px; }
}
@media (max-width: 1240px) {
  :root { --lead-w: 440px; --col-gap: 48px; }
}
@media (max-width: 1080px) {
  .footer-grid { gap: 32px; grid-template-columns: 1.2fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 768px) {
  :root { --gutter: 20px; --nav-h: 64px; --size-h1: 30px; }
  h1 { font-size: var(--size-mobile-title); }
  .grid-two { grid-template-columns: minmax(0, 1fr); }
  .card, .panel { padding: 24px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-brand { grid-column: auto; }
  .site-footer { padding-top: 40px; }
}
@media (max-width: 640px) {
  .tilt, [data-tilt] { transform: none !important; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .brand-name { font-size: var(--size-nav); }
  .brand-sub { font-size: var(--size-tiny); overflow-wrap: anywhere; }
  .brand { gap: 8px; flex-shrink: 1; min-width: 0; }
  .brand-text { min-width: 0; }
  .brand-name { overflow-wrap: anywhere; }
  .masthead-row { gap: 8px; }
  .lang { min-height: 44px; padding-inline: 10px; }
  .prose { font-size: var(--size-body); }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal-ready .reveal { opacity: 1; transform: none; }
}