:root {
  --bg: #fdfdfc;
  --fg: #1d1f21;
  --muted: #5f6368;
  --accent: #2b6cb0;
  --card: #f2f4f7;
  --border: #e2e5ea;
  --radius: 10px;
  --max: 64rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171a;
    --fg: #e8eaed;
    --muted: #a0a6ad;
    --accent: #7ab3ef;
    --card: #1f2226;
    --border: #2d3136;
  }
}

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--fg);
  background: var(--bg);
}

a { color: var(--accent); }

h1, h2, h3 { line-height: 1.2; }

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1rem;
}

/* Header */
.site-header { border-bottom: 1px solid var(--border); }
.site-header .wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding-block: 1rem;
}
.brand {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--fg);
  text-decoration: none;
}
nav ul {
  display: flex;
  gap: 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
nav a { color: var(--muted); text-decoration: none; }
nav a:hover, nav a:focus-visible { color: var(--fg); }

/* Hero */
.hero { padding: 4rem 0 3rem; }
.hero h1 { font-size: clamp(2rem, 6vw, 3.25rem); margin: 0 0 0.75rem; }
.lead { font-size: 1.2rem; color: var(--muted); max-width: 40rem; }
.button {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius);
  background: var(--accent);
  color: var(--bg);
  font-weight: 600;
  text-decoration: none;
}
.button:hover, .button:focus-visible { filter: brightness(1.1); }

/* Sections */
main section:not(.hero) { padding-block: 2rem; }

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}
.card {
  padding: 1.25rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
}
.card h3 { margin-top: 0; }
.card p { margin-bottom: 0; color: var(--muted); }

/* Footer */
.site-footer {
  margin-top: 3rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
}

@media (max-width: 48rem) {
  .cards { grid-template-columns: 1fr; }
  .hero { padding: 2.5rem 0 2rem; }
}