:root {
  color-scheme: light;
  --ink: #111311;
  --muted: #6d7068;
  --paper: #f7f6ef;
  --paper-strong: #fffef9;
  --line: #deddd2;
  --acid: #dfff00;
  --acid-soft: #f1ff8a;
  --black: #0f1110;
  --radius-lg: 34px;
  --radius-md: 24px;
  --shadow: 0 24px 80px rgba(25, 28, 21, 0.1);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Helvetica Neue", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  overflow-x: clip;
  color: var(--ink);
  background:
    radial-gradient(circle at 88% 4%, rgba(223, 255, 0, 0.16), transparent 26rem),
    var(--paper);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }
img { display: block; max-width: 100%; }
button, a { -webkit-tap-highlight-color: transparent; }

.site-shell { min-height: 100vh; }
.container { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }

.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: saturate(150%) blur(20px);
  background: rgba(247, 246, 239, 0.82);
  border-bottom: 1px solid rgba(17, 19, 17, 0.08);
}
.nav-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.brand { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; font-weight: 720; }
.brand img { width: 42px; height: 42px; border-radius: 12px; }
.brand-cn { display: block; font-size: 17px; line-height: 1.1; }
.brand-en { display: block; margin-top: 4px; color: var(--muted); font-size: 11px; letter-spacing: .04em; }
.nav-links { display: flex; align-items: center; gap: 24px; color: var(--muted); font-size: 14px; }
.nav-links a { text-decoration: none; }
.nav-links a:hover { color: var(--ink); }
.nav-status { padding: 8px 14px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink); }

.hero {
  min-height: min(720px, calc(100svh - 76px));
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(360px, .98fr);
  align-items: center;
  gap: clamp(40px, 7vw, 96px);
  padding: 72px 0 78px;
}
.eyebrow { display: inline-flex; align-items: center; gap: 9px; color: var(--muted); font-size: 14px; }
.eyebrow-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--acid); box-shadow: 0 0 0 5px rgba(223,255,0,.18); }
h1, h2, h3, p { margin-top: 0; }
h1 { margin: 26px 0 26px; font-size: clamp(52px, 7.2vw, 94px); line-height: .98; letter-spacing: -.065em; }
h1 .flow { display: block; color: var(--muted); font-weight: 500; }
.hero-copy { max-width: 650px; color: #454940; font-size: clamp(18px, 2vw, 22px); line-height: 1.65; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 0 22px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 680;
}
.button-primary { background: var(--black); color: white; }
.button-secondary { border: 1px solid var(--line); background: rgba(255,255,255,.52); }
.small-note { margin-top: 15px; color: var(--muted); font-size: 13px; }

.hero-visual { position: relative; min-height: 580px; display: grid; place-items: center; }
.stack-card {
  position: absolute;
  width: min(440px, 88%);
  height: 500px;
  border-radius: 38px;
  border: 1px solid rgba(17,19,17,.08);
  box-shadow: var(--shadow);
}
.stack-card.back { transform: translate(38px,-34px) rotate(5deg); background: #e8e8df; }
.stack-card.middle { transform: translate(18px,-17px) rotate(2deg); background: #f0efe8; }
.stack-card.front { position: relative; padding: 34px; background: var(--paper-strong); display: flex; flex-direction: column; }
.card-meta { color: var(--muted); font-size: 13px; }
.card-word { margin-top: 70px; font-family: Georgia, "Times New Roman", serif; font-size: clamp(50px, 7vw, 74px); font-weight: 700; letter-spacing: -.04em; }
.card-meaning { font-size: 22px; }
.card-divider { height: 1px; background: var(--line); margin: 28px 0; }
.memory-line { margin-top: auto; padding: 17px 18px; border-radius: 18px; background: #f1f4e4; font-size: 15px; }
.memory-line strong { text-decoration: underline 5px var(--acid); text-underline-offset: 4px; }
.timeline { position: absolute; left: -18px; top: 74px; bottom: 74px; width: 2px; background: #d6d7cd; }
.timeline::before, .timeline::after { content: ""; position: absolute; left: -5px; width: 12px; height: 12px; border-radius: 50%; background: var(--acid); border: 2px solid var(--ink); }
.timeline::before { top: 48px; }
.timeline::after { bottom: 48px; background: var(--paper); }

.section { padding: 88px 0; border-top: 1px solid rgba(17,19,17,.1); }
.section-head { max-width: 820px; margin-bottom: 42px; }
.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 620;
}
.section-kicker::before {
  content: "";
  width: 26px;
  height: 2px;
  border-radius: 999px;
  background: var(--acid);
  box-shadow: 0 0 0 1px rgba(17,19,17,.08);
}
h2 { font-size: clamp(38px, 4.4vw, 58px); line-height: 1.08; letter-spacing: -.045em; }
.section-head h2 { margin-bottom: 22px; }
.section-lead { max-width: 720px; margin-bottom: 0; color: var(--muted); font-size: 18px; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.feature {
  min-height: 276px;
  padding: 30px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(255,255,255,.6);
}
.feature.dark { color: white; background: var(--black); border-color: var(--black); }
.feature-number { color: var(--muted); font-size: 13px; }
.feature.dark .feature-number { color: #9ca097; }
.feature h3 { margin: 52px 0 16px; font-size: 28px; line-height: 1.25; letter-spacing: -.03em; }
.feature p { color: var(--muted); }
.feature.dark p { color: #c6c8c2; }

.markets { display: flex; flex-wrap: wrap; gap: 12px; }
.market-pill { padding: 14px 19px; border: 1px solid var(--line); border-radius: 999px; background: var(--paper-strong); }
.market-pill:first-child { background: var(--acid); border-color: var(--acid); }
.flow-strip { margin-top: 48px; display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); border-radius: var(--radius-md); overflow: hidden; }
.flow-step { padding: 28px 22px; background: rgba(255,255,255,.56); border-right: 1px solid var(--line); }
.flow-step:last-child { border-right: 0; }
.flow-step span { display: block; color: var(--muted); font-size: 12px; }
.flow-step strong { display: block; margin-top: 18px; font-size: 19px; }

.privacy-panel { display: grid; grid-template-columns: 1fr 1fr; gap: 36px; padding: 46px; border-radius: var(--radius-lg); background: var(--black); color: white; }
.privacy-panel .section-kicker { margin-bottom: 16px; }
.privacy-panel p { color: #c9cbc5; max-width: 560px; }
.privacy-points { display: grid; gap: 12px; }
.privacy-point { padding: 17px 18px; border: 1px solid #323531; border-radius: 16px; }
.privacy-point::before { content: "✓"; color: var(--acid); margin-right: 10px; }

.cta { padding: 110px 0 130px; text-align: center; }
.cta-card { padding: 72px 30px; border-radius: var(--radius-lg); background: var(--acid); }
.cta-card h2 { margin-bottom: 18px; }
.cta-card p { color: #45483c; }

.footer { padding: 34px 0 50px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.footer-inner { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }
.footer a { text-decoration: none; }
.filing-placeholder { margin-top: 12px; color: #95988f; }

.legal-main { padding: 72px 0 110px; }
.legal-header { max-width: 820px; margin-bottom: 50px; }
.legal-header h1 { font-size: clamp(42px, 6vw, 72px); }
.legal-meta { color: var(--muted); }
.legal-content { max-width: 820px; }
.legal-content h2 { margin: 50px 0 18px; font-size: 27px; letter-spacing: -.025em; }
.legal-content h3 { margin: 28px 0 10px; font-size: 19px; }
.legal-content p, .legal-content li { color: #454940; }
.legal-content ul { padding-left: 1.3em; }
.legal-callout { margin: 28px 0; padding: 22px; border-radius: 18px; background: #eff2df; }
.license-item { padding: 22px 0; border-bottom: 1px solid var(--line); }
.license-item:last-child { border-bottom: 0; }

@media (max-width: 820px) {
  .container { width: min(100% - 28px, 680px); }
  .nav-links a:not(.nav-status) { display: none; }
  .hero { min-height: auto; grid-template-columns: 1fr; padding: 54px 0 76px; }
  .hero-visual { min-height: 530px; margin-top: 10px; }
  .stack-card { height: 470px; }
  .section { padding: 68px 0; }
  .section-head { margin-bottom: 34px; }
  .privacy-panel { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .feature { min-height: auto; }
  .feature h3 { margin-top: 36px; }
  .flow-strip { grid-template-columns: 1fr 1fr; }
  .flow-step:nth-child(2) { border-right: 0; }
  .flow-step:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
}

@media (max-width: 520px) {
  .nav-inner { min-height: 68px; }
  .brand img { width: 38px; height: 38px; }
  .nav-status { padding: 7px 11px; }
  h1 { font-size: 52px; }
  .hero-copy { font-size: 17px; }
  .hero-visual { min-height: 470px; }
  .stack-card { height: 420px; border-radius: 29px; }
  .stack-card.front { padding: 25px; }
  .card-word { margin-top: 48px; font-size: 52px; }
  .card-meaning { font-size: 19px; }
  .section-head h2 { margin-bottom: 18px; }
  .flow-strip { grid-template-columns: 1fr; }
  .flow-step { border-right: 0; border-bottom: 1px solid var(--line); }
  .flow-step:last-child { border-bottom: 0; }
  .privacy-panel { padding: 30px 22px; }
  .cta-card { padding: 54px 22px; }
}

@media (prefers-reduced-motion: no-preference) {
  .stack-card.front { animation: settle .75s cubic-bezier(.2,.75,.25,1) both; }
  @keyframes settle { from { opacity: 0; transform: translateY(18px) rotate(-1deg); } to { opacity: 1; transform: translateY(0) rotate(0); } }
}