:root {
  color-scheme: light;
  --bg: #f5f7f5;
  --surface: #ffffff;
  --text: #1d2923;
  --muted: #607068;
  --line: #dfe7e2;
  --accent: #176b4d;
  --accent-dark: #0f5139;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}

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

.site-header,
main,
footer {
  width: min(68rem, calc(100% - 2.5rem));
  margin-inline: auto;
}

.site-header {
  min-height: 4.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  border-bottom: 1px solid var(--line);
}

.brand {
  color: var(--text);
  font-weight: 750;
  letter-spacing: -.02em;
  text-decoration: none;
}

nav { display: flex; gap: 1.25rem; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover,
nav a[aria-current="page"] { color: var(--text); }

main { flex: 1; }

.hero { padding: 7rem 0 5rem; max-width: 48rem; }
.eyebrow,
.error-code {
  margin: 0 0 .75rem;
  color: var(--accent);
  font-size: .78rem;
  font-weight: 750;
  letter-spacing: .13em;
  text-transform: uppercase;
}

h1 {
  margin: 0 0 1.25rem;
  font-size: clamp(2.5rem, 7vw, 5.25rem);
  line-height: 1.02;
  letter-spacing: -.055em;
}

.lead {
  max-width: 41rem;
  margin: 0 0 2rem;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.3rem);
}

.button {
  display: inline-block;
  padding: .7rem 1rem;
  border-radius: .65rem;
  background: var(--accent);
  color: #fff;
  font-weight: 650;
  text-decoration: none;
}
.button:hover { background: var(--accent-dark); }

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  padding-bottom: 6rem;
}

.cards article {
  padding: 1.35rem;
  border: 1px solid var(--line);
  border-radius: .9rem;
  background: var(--surface);
}

.cards h2 { margin: 0 0 .4rem; font-size: 1.05rem; }
.cards p { margin: 0; color: var(--muted); font-size: .94rem; }

.prose { max-width: 46rem; padding: 7rem 0; }
.prose h1 { font-size: clamp(2.25rem, 6vw, 4rem); }
.prose p { color: var(--muted); font-size: 1.05rem; }
.prose p a:not(.button) { font-weight: 650; }
.error-page { text-align: center; }
.error-code { font-size: 1rem; }

footer {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.5rem 0 2.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: .88rem;
}

@media (max-width: 680px) {
  .site-header { align-items: flex-start; flex-direction: column; justify-content: center; padding: 1rem 0; }
  nav { gap: 1rem; }
  .hero, .prose { padding: 4.5rem 0; }
  .cards { grid-template-columns: 1fr; }
  footer { flex-direction: column; }
}