*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #000;
  --bg-subtle: #0a0a0a;
  --surface: #111;
  --border: #1a1a1a;
  --text: #f5f5f7;
  --text-secondary: #86868b;
  --accent: #4a90d9;
  --accent-dim: #2a5a8a;
  --nano-blue: #209CE9;
  --mono: "SF Mono", "Menlo", "Consolas", "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", Arial, sans-serif;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}

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

/* Layout */

.container {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Hero */

.hero {
  padding: 80px 0 40px;
  text-align: center;
}

.hero-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 12px;
}

.hero .subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Sections */

section {
  padding: 40px 0;
}

section h2 {
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
}

section p {
  color: var(--text-secondary);
  margin-bottom: 16px;
  font-size: 1.05rem;
}

section p strong {
  color: var(--text);
  font-weight: 500;
}

/* The Argument */

.argument {
  border-top: 1px solid var(--border);
}

.argument h3 {
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text);
  margin-top: 40px;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.argument .call {
  color: var(--text);
  font-size: 1.05rem;
  line-height: 1.8;
}

.argument .conclusion {
  margin-top: 40px;
  padding: 28px;
  background: var(--surface);
  border-radius: 12px;
  border: 1px solid var(--border);
}

.argument .conclusion p {
  color: var(--text);
  font-size: 1.05rem;
  margin-bottom: 0;
}

.argument .conclusion .conclusion-result {
  margin-top: 16px;
}

/* Properties */

.properties {
  list-style: none;
  margin-top: 32px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.properties li {
  padding: 20px;
  background: var(--surface);
  font-size: 0.95rem;
  line-height: 1.6;
}

.properties li strong {
  display: block;
  color: var(--text);
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 4px;
}

.properties li span {
  color: var(--text-secondary);
  font-size: 0.88rem;
}

/* Proof / x402 */

.proof {
  border-top: 1px solid var(--border);
}

.proof .flow {
  margin: 24px 0;
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  font-family: var(--mono);
  font-size: 0.85rem;
  line-height: 2;
  color: var(--text-secondary);
}

.proof .flow .step {
  display: flex;
  gap: 12px;
  align-items: baseline;
}

.proof .flow .step-num {
  color: var(--accent-dim);
  min-width: 16px;
  font-weight: 600;
}

.proof .flow .step-text {
  color: var(--text-secondary);
}

.proof .flow .step-highlight {
  color: var(--text);
}

/* Comparison */

.comparison {
  border-top: 1px solid var(--border);
}

.comparison table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 16px;
  font-size: 0.95rem;
}

.comparison th {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.comparison th[scope="row"] {
  color: var(--text);
  font-weight: 500;
  text-transform: none;
  letter-spacing: normal;
  font-size: 0.95rem;
}

.comparison td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
}

.comparison .yes {
  color: var(--text);
}

.comparison .no {
  color: #444;
}

/* Resources */

.resources {
  border-top: 1px solid var(--border);
}

.resource-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  margin-top: 16px;
}

.resource-link {
  display: block;
  padding: 16px 20px;
  background: var(--surface);
  transition: background 0.2s;
}

.resource-link:hover {
  background: #161616;
}

.resource-link .name {
  color: var(--text);
  font-weight: 500;
  font-size: 0.95rem;
  margin-bottom: 2px;
}

.resource-link .desc {
  color: var(--text-secondary);
  font-size: 0.82rem;
  line-height: 1.5;
}

/* Footer */

footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.82rem;
}

footer a {
  color: var(--text-secondary);
}

footer a:hover {
  color: var(--text);
}

footer p {
  margin-bottom: 4px;
}

/* Responsive */

@media (max-width: 600px) {
  .hero {
    padding: 60px 0 32px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero .subtitle {
    font-size: 1rem;
  }

  section {
    padding: 32px 0;
  }

  section h2 {
    font-size: 1.3rem;
  }

  .argument h3 {
    font-size: 1.15rem;
  }

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

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

  .comparison table {
    font-size: 0.82rem;
  }

  .comparison th,
  .comparison td {
    padding: 8px 6px;
  }
}