@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500&display=swap');

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; scroll-behavior: smooth; }

/* ── Design Tokens ── */
:root {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --bg-card-hover: #334155;
  --bg-input: #334155;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --border: #334155;
  --border-light: #475569;
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --transition: 150ms ease;
  --max-width: 960px;
}

/* ── Base ── */
body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-hover); }
code, .mono { font-family: var(--font-mono); font-size: 0.9em; }

/* ── Layout ── */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.section { padding: 64px 0; }
.section + .section { border-top: 1px solid var(--border); }

/* ── Navigation ── */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 56px;
}
.nav-brand {
  display: flex; align-items: center; gap: 10px;
  color: var(--text-primary); font-weight: 700; font-size: 1.125rem;
}
.nav-brand:hover { color: var(--text-primary); }
.nav-brand img { border-radius: 50%; }
.nav-links { display: flex; gap: 24px; align-items: center; }
.nav-links a { color: var(--text-secondary); font-size: 0.9rem; font-weight: 500; }
.nav-links a:hover { color: var(--text-primary); }
.nav-links a.active { color: var(--accent); }
.nav-links .ext::after { content: ' ↗'; font-size: 0.75em; opacity: 0.6; }
.nav-hamburger {
  display: none; background: none; border: none; cursor: pointer;
  color: var(--text-secondary); padding: 4px;
}
.nav-mobile {
  display: none; flex-direction: column; gap: 0;
  background: var(--bg-secondary); border-bottom: 1px solid var(--border);
}
.nav-mobile a {
  display: block; padding: 12px 24px;
  color: var(--text-secondary); font-size: 0.9rem; font-weight: 500;
  border-top: 1px solid var(--border);
}
.nav-mobile a:hover { color: var(--text-primary); background: var(--bg-card-hover); }
.nav-mobile a.active { color: var(--accent); }
.nav-mobile.open { display: flex; }

/* ── Hero ── */
.hero {
  text-align: center; padding: 80px 0 64px;
}
.hero img { margin-bottom: 24px; border-radius: 50%; }
.hero h1 {
  font-size: 2.75rem; font-weight: 700; letter-spacing: -0.02em;
  line-height: 1.15; margin-bottom: 16px;
}
.hero-subtitle {
  font-size: 1.2rem; color: var(--text-secondary); max-width: 540px;
  margin: 0 auto 32px; line-height: 1.6;
}
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ── Buttons ── */
.btn-primary {
  display: inline-block; padding: 10px 24px; border-radius: var(--radius-md);
  background: var(--accent); color: #fff; font-weight: 600; font-size: 0.95rem;
  transition: background var(--transition);
}
.btn-primary:hover { background: var(--accent-hover); color: #fff; }
.btn-outline {
  display: inline-block; padding: 10px 24px; border-radius: var(--radius-md);
  border: 1px solid var(--border-light); color: var(--text-secondary); font-weight: 600; font-size: 0.95rem;
  transition: border-color var(--transition), color var(--transition);
}
.btn-outline:hover { border-color: var(--accent); color: var(--text-primary); }

/* ── Cards ── */
.card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 24px;
  transition: background var(--transition), border-color var(--transition);
}
.card-clickable { display: block; color: var(--text-primary); }
.card-clickable:hover { background: var(--bg-card-hover); border-color: var(--border-light); color: var(--text-primary); }
.card h3 { font-size: 1rem; font-weight: 600; margin-bottom: 6px; }
.card p { color: var(--text-secondary); font-size: 0.9rem; line-height: 1.5; }
.card .card-label { font-size: 0.8rem; color: var(--text-muted); margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.05em; }
.card .card-icon { font-size: 1.5rem; margin-bottom: 12px; }

/* ── Grids ── */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }

/* ── Section Headings ── */
.section h2 {
  font-size: 1.75rem; font-weight: 700; margin-bottom: 12px;
  letter-spacing: -0.01em;
}
.section .section-lead {
  color: var(--text-secondary); font-size: 1.05rem; margin-bottom: 32px;
  max-width: 640px; line-height: 1.6;
}
.section h2 + .grid-2,
.section h2 + .grid-3 { margin-top: 32px; }

/* ── Code Blocks ── */
pre {
  background: var(--bg-secondary); border: 1px solid var(--border);
  border-radius: var(--radius-md); padding: 20px; overflow-x: auto;
  font-family: var(--font-mono); font-size: 0.85rem; line-height: 1.7;
  color: var(--text-primary);
}
pre.diagram { font-size: 0.8rem; line-height: 1.5; color: var(--text-secondary); }
.code-keyword { color: #c084fc; }
.code-string  { color: #a5f3fc; }
.code-comment { color: #64748b; }
.code-func    { color: #fbbf24; }
.code-type    { color: #34d399; }
.code-num     { color: #fb923c; }

/* ── Inline Code ── */
:not(pre) > code {
  background: var(--bg-secondary); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 2px 6px;
  font-size: 0.85em;
}

/* ── CSS-Only Tabs ── */
.tabs { margin: 0; }
.tabs input[type="radio"] { position: absolute; opacity: 0; pointer-events: none; }
.tabs .tab-labels { display: flex; gap: 0; margin-bottom: -1px; }
.tabs label {
  display: inline-block; padding: 8px 20px; cursor: pointer;
  font-size: 0.85rem; font-weight: 500; color: var(--text-muted);
  border: 1px solid transparent; border-bottom: none;
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  transition: color var(--transition), background var(--transition);
}
.tabs label:hover { color: var(--text-secondary); }
.tabs .tab-content { display: none; }

/* Python/TS install tabs */
#tab-py-install:checked ~ .tab-labels label[for="tab-py-install"],
#tab-ts-install:checked ~ .tab-labels label[for="tab-ts-install"],
#tab-py-buyer:checked ~ .tab-labels label[for="tab-py-buyer"],
#tab-ts-buyer:checked ~ .tab-labels label[for="tab-ts-buyer"],
#tab-py-seller:checked ~ .tab-labels label[for="tab-py-seller"],
#tab-ts-seller:checked ~ .tab-labels label[for="tab-ts-seller"] {
  color: var(--accent); background: var(--bg-secondary);
  border-color: var(--border);
}

#tab-py-install:checked ~ #content-py-install,
#tab-ts-install:checked ~ #content-ts-install,
#tab-py-buyer:checked ~ #content-py-buyer,
#tab-ts-buyer:checked ~ #content-ts-buyer,
#tab-py-seller:checked ~ #content-py-seller,
#tab-ts-seller:checked ~ #content-ts-seller { display: block; }

/* ── Tables ── */
table {
  width: 100%; border-collapse: collapse; font-size: 0.9rem;
}
th, td {
  text-align: left; padding: 10px 14px;
  border-bottom: 1px solid var(--border);
}
th {
  background: var(--bg-secondary); color: var(--text-secondary);
  font-weight: 600; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.04em;
}
td { color: var(--text-primary); }
td code { font-size: 0.85em; }
tr:hover td { background: rgba(59,130,246,0.04); }

/* ── Hex Badge ── */
.hex-badge {
  display: inline-block; padding: 2px 8px; border-radius: var(--radius-sm);
  background: rgba(59,130,246,0.12); color: var(--accent);
  font-family: var(--font-mono); font-size: 0.8rem; font-weight: 500;
}

/* ── Status Badge ── */
.status-badge {
  display: inline-block; padding: 2px 10px; border-radius: var(--radius-sm);
  font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.04em;
}
.status-badge.draft { background: rgba(59,130,246,0.12); color: var(--accent); }
.status-badge.planned { background: rgba(100,116,139,0.2); color: var(--text-muted); }

/* ── Footer ── */
.footer {
  border-top: 1px solid var(--border); padding: 24px 0;
  text-align: center; color: var(--text-muted); font-size: 0.85rem;
}
.footer a { color: var(--text-muted); }
.footer a:hover { color: var(--accent); }

/* ── Page Header ── */
.page-header { padding: 48px 0 0; }
.page-header h1 { font-size: 2.25rem; font-weight: 700; margin-bottom: 8px; letter-spacing: -0.02em; }
.page-header p { color: var(--text-secondary); font-size: 1.1rem; }

/* ── Prose ── */
.prose p { color: var(--text-secondary); margin-bottom: 16px; line-height: 1.7; }
.prose p:last-child { margin-bottom: 0; }

/* ── Use Case List ── */
.use-cases { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.use-case {
  display: flex; align-items: baseline; gap: 10px;
  padding: 12px 16px; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-md);
}
.use-case strong { font-size: 0.9rem; white-space: nowrap; }
.use-case span { color: var(--text-secondary); font-size: 0.85rem; }

/* ── Links Section ── */
.links-section .card h3 { margin-bottom: 4px; }
.links-section .card p { font-size: 0.85rem; }

/* ── Docs Steps ── */
.step { margin-bottom: 40px; }
.step h3 { font-size: 1.15rem; font-weight: 600; margin-bottom: 12px; }
.step p { color: var(--text-secondary); margin-bottom: 12px; }

/* ── Responsive ── */
@media (max-width: 768px) {
  .container { padding: 0 16px; }
  .section { padding: 40px 0; }
  .hero { padding: 48px 0 40px; }
  .hero h1 { font-size: 2rem; }
  .hero-subtitle { font-size: 1.05rem; }
  .grid-2, .grid-3, .use-cases { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .nav-hamburger { display: block; }
  .page-header h1 { font-size: 1.75rem; }
  pre { font-size: 0.8rem; padding: 16px; }
}
@media (max-width: 480px) {
  .hero h1 { font-size: 1.5rem; }
  .hero-actions { flex-direction: column; align-items: center; }
}