:root {
  --bg: #06080f;
  --bg-elevated: #0d111c;
  --bg-card: #121826;
  --border: rgba(148, 163, 184, 0.12);
  --text: #e8edf5;
  --text-muted: #94a3b8;
  --accent: #22d3ee;
  --accent-dim: rgba(34, 211, 238, 0.12);
  --green: #34d399;
  --amber: #fbbf24;
  --purple: #a78bfa;
  --radius: 14px;
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
  --font: "Inter", ui-sans-serif, system-ui, -apple-system, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(circle at 15% 0%, rgba(34, 211, 238, 0.08), transparent 42%),
    radial-gradient(circle at 85% 10%, rgba(167, 139, 250, 0.06), transparent 38%);
  pointer-events: none;
  z-index: -1;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
}

/* Nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  background: rgba(6, 8, 15, 0.82);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), var(--purple));
  display: grid;
  place-items: center;
  font-size: 0.95rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.92rem;
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--text);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.lang-btn {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-muted);
  border-radius: 999px;
  padding: 0.35rem 0.75rem;
  font-size: 0.82rem;
  cursor: pointer;
}

.lang-btn.active {
  color: var(--accent);
  border-color: rgba(34, 211, 238, 0.35);
  background: var(--accent-dim);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  border-radius: 999px;
  padding: 0.65rem 1.15rem;
  font-size: 0.92rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: linear-gradient(135deg, #0891b2, #22d3ee);
  color: #041016;
  box-shadow: 0 10px 30px rgba(34, 211, 238, 0.25);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.4rem;
  cursor: pointer;
}

/* Hero */
.hero {
  padding: 4.5rem 0 3rem;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-muted);
  font-size: 0.82rem;
  margin-bottom: 1.25rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2.5rem;
  align-items: center;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  margin: 0 0 1rem;
}

.hero-lead {
  color: var(--text-muted);
  font-size: 1.08rem;
  max-width: 34rem;
  margin: 0 0 1.75rem;
}

.author-strip {
  margin: -0.5rem 0 1rem;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.author-strip a {
  color: var(--accent);
  font-weight: 600;
}

.cite-block {
  margin: 0;
  padding: 1.1rem 1.25rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.25);
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.55;
  color: var(--text-muted);
}

.cite-block code {
  font-family: inherit;
}

.footer-copy {
  margin-top: 1rem;
  opacity: 0.7;
  font-size: 0.85rem;
}

.footer-copy a {
  color: var(--text-muted);
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
}

.stat {
  padding: 0.85rem 1rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
}

.stat-value {
  display: block;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-label {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.hero-card {
  border-radius: calc(var(--radius) + 4px);
  border: 1px solid var(--border);
  background: var(--bg-card);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.hero-card img {
  display: block;
  width: 100%;
  height: auto;
}

.hero-card-caption {
  padding: 0.85rem 1rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}

/* Sections */
section {
  padding: 3.5rem 0;
}

.section-head {
  margin-bottom: 2rem;
}

.section-head h2 {
  margin: 0 0 0.5rem;
  font-size: 1.75rem;
  letter-spacing: -0.02em;
}

.section-head p {
  margin: 0;
  color: var(--text-muted);
  max-width: 40rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.card {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  padding: 1.25rem;
}

.card-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  margin-bottom: 0.85rem;
  font-size: 1.1rem;
}

.card-icon.cyan { background: var(--accent-dim); }
.card-icon.green { background: rgba(52, 211, 153, 0.12); }
.card-icon.purple { background: rgba(167, 139, 250, 0.12); }
.card-icon.amber { background: rgba(251, 191, 36, 0.12); }

.card h3 {
  margin: 0 0 0.45rem;
  font-size: 1.05rem;
}

.card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.92rem;
}

/* Flow */
.flow {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.65rem;
}

.flow-step {
  position: relative;
  padding: 1rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
  text-align: center;
}

.flow-step strong {
  display: block;
  font-size: 0.88rem;
  margin-bottom: 0.25rem;
}

.flow-step span {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.flow-step:not(:last-child)::after {
  content: "→";
  position: absolute;
  right: -0.55rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--accent);
  font-size: 0.9rem;
  z-index: 1;
}

/* Demo */
.demo-frame {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow: hidden;
  background: var(--bg-card);
}

.demo-frame img {
  width: 100%;
  display: block;
}

.demo-caption {
  padding: 0.85rem 1rem;
  font-size: 0.88rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}

/* Table */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

th,
td {
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-muted);
  font-weight: 600;
}

tr:last-child td {
  border-bottom: none;
}

.tag {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
}

.tag-crypto {
  background: rgba(34, 211, 238, 0.12);
  color: var(--accent);
}

.tag-equity {
  background: rgba(167, 139, 250, 0.12);
  color: var(--purple);
}

/* Stack */
.stack {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.chip {
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* Footer */
.footer {
  padding: 2.5rem 0 3rem;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
}

.footer-links {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.disclaimer {
  margin-top: 1.25rem;
  padding: 1rem;
  border-radius: var(--radius);
  border: 1px solid rgba(251, 191, 36, 0.2);
  background: rgba(251, 191, 36, 0.06);
  color: #fcd34d;
  font-size: 0.82rem;
}

[lang="zh"] .en-only,
[lang="en"] .zh-only {
  display: none !important;
}

@media (max-width: 900px) {
  .hero-grid,
  .grid-3,
  .grid-2 {
    grid-template-columns: 1fr;
  }

  .stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .flow {
    grid-template-columns: 1fr;
  }

  .flow-step:not(:last-child)::after {
    content: "↓";
    right: auto;
    left: 50%;
    top: auto;
    bottom: -0.55rem;
    transform: translateX(-50%);
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    padding: 1rem;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
  }

  .nav-links.open {
    display: flex;
  }

  .menu-toggle {
    display: block;
  }
}