/* DuelLab root landing – serious research lab with light data-dashboard accent */

:root {
  --bg: #0d1117;
  --surface: #161b22;
  --text: #e6edf3;
  --muted: #8b949e;
  --accent: #58a6ff;
  --accent-soft: rgba(88, 166, 255, 0.15);
  --border: #30363d;
  --font: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --wrap: min(720px, 90vw);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}

.wrap {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 1.5rem;
}

@media (min-width: 640px) {
  .wrap {
    padding: 0 2rem;
  }
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: 0.02em;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 500;
}

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

/* Hero */
.hero {
  padding: 3.5rem 0 4rem;
}

.hero h1 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 600;
  margin: 0 0 1rem;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.lead {
  font-size: 1.125rem;
  color: var(--muted);
  margin: 0 0 1.75rem;
  max-width: 42ch;
}

.cta-primary {
  margin: 0;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.35rem;
  font-size: 1rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: 6px;
  border: 1px solid transparent;
  transition: background 0.15s ease, color 0.15s ease;
}

.btn-primary {
  background: var(--accent);
  color: var(--bg);
}

.btn-primary:hover {
  background: #79b8ff;
}

/* Sections */
.use-cases,
.mission,
.audience,
.trust,
.cta-footer {
  padding: 2.25rem 0;
  border-top: 1px solid var(--border);
}

.use-cases ul,
.audience ul {
  margin: 0;
  padding-left: 1.25rem;
}

.use-cases li,
.audience li {
  margin-bottom: 0.6rem;
}

h2 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 0 0 1rem;
  letter-spacing: -0.01em;
  color: var(--text);
}

.trust p,
.mission p {
  margin: 0;
}

.cta-footer {
  padding-bottom: 2.5rem;
}

.cta-footer .sep {
  color: var(--muted);
  margin: 0 0.5rem;
}

.cta-footer a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.cta-footer a:hover {
  text-decoration: underline;
}

/* Footer */
.site-footer {
  padding: 2rem 0;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
}

.site-footer p {
  margin: 0;
}