:root {
  --bg: #fafaf9;
  --fg: #1c1917;
  --muted: #57534e;
  --card: #ffffff;
  --border: #e7e5e4;
  --accent: #2563eb;
  --accent-fg: #ffffff;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c0a09;
    --fg: #f5f5f4;
    --muted: #a8a29e;
    --card: #1c1917;
    --border: #292524;
    --accent: #60a5fa;
    --accent-fg: #0c0a09;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

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

.site-header {
  position: sticky;
  top: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  padding: 1rem clamp(1rem, 5vw, 3rem);
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}

.logo {
  font-weight: 800;
  text-decoration: none;
  color: var(--fg);
  letter-spacing: 0.05em;
}

nav { display: flex; gap: 1.25rem; flex-wrap: wrap; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover { color: var(--fg); }

main {
  max-width: 56rem;
  margin: 0 auto;
  padding: 0 clamp(1rem, 5vw, 3rem);
}

section { padding-block: 3rem; scroll-margin-top: 4rem; }

.hero { padding-block: 6rem 4rem; }
.hero h1 { font-size: clamp(2.5rem, 8vw, 4rem); line-height: 1.1; margin: 0 0 1rem; }
.tagline { font-size: 1.25rem; color: var(--muted); margin: 0 0 2rem; }

.links { display: flex; gap: 0.75rem; flex-wrap: wrap; }

.button {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  border-radius: 0.5rem;
  background: var(--accent);
  color: var(--accent-fg);
  text-decoration: none;
  font-weight: 600;
}
.button.secondary {
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--border);
}

h2 { font-size: 1.75rem; margin: 0 0 1.5rem; }
h3 { margin: 0 0 0.5rem; font-size: 1.1rem; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr));
  gap: 1rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 1.25rem;
}
.card p { margin: 0 0 0.75rem; }
.card a { text-decoration: none; font-weight: 600; }

.tags { color: var(--muted); font-size: 0.875rem; }

.timeline { list-style: none; padding: 0; margin: 0; }
.timeline li {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: 1rem;
  padding-block: 1rem;
  border-top: 1px solid var(--border);
}
.timeline p { margin: 0; color: var(--muted); }
.when { color: var(--muted); font-size: 0.9rem; }

@media (max-width: 600px) {
  .timeline li { grid-template-columns: 1fr; gap: 0.25rem; }
}

footer {
  text-align: center;
  color: var(--muted);
  padding: 3rem 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.875rem;
}

.not-found {
  min-height: 70vh;
  display: grid;
  place-content: center;
  text-align: center;
}