:root {
  color-scheme: light dark;
  --background: #f4f7f8;
  --surface: #ffffff;
  --text: #17252b;
  --muted: #61727a;
  --border: #dce6e8;
  --accent: #0f766e;
  --accent-soft: #e2f4f1;
  --accent-strong: #0b5d57;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #101819;
    --surface: #172122;
    --text: #eef7f6;
    --muted: #aec1c0;
    --border: #2c3c3d;
    --accent: #66d4c6;
    --accent-soft: #1d3837;
    --accent-strong: #a0eee4;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.7;
}

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

.site-header,
.site-footer,
.page {
  width: min(920px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 28px 0 20px;
}

.brand {
  color: var(--text);
  font-size: 1.1rem;
  font-weight: 760;
  text-decoration: none;
  letter-spacing: .02em;
}

nav { display: flex; flex-wrap: wrap; gap: 16px; }
nav a { font-size: .92rem; text-decoration: none; }

.hero { padding: 60px 0 36px; }

.eyebrow {
  color: var(--accent);
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}

h1, h2, h3 { line-height: 1.25; }
h1 { max-width: 760px; margin: 12px 0 20px; font-size: clamp(2.1rem, 6vw, 4rem); letter-spacing: -.04em; }
h2 { margin-top: 2.2em; font-size: 1.35rem; }
h3 { margin-top: 1.8em; font-size: 1.05rem; }
p, li { max-width: 760px; }

.lead { color: var(--muted); font-size: 1.15rem; max-width: 700px; }

.cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin: 22px 0 80px;
}

.card {
  display: block;
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  transition: border-color .15s ease, transform .15s ease;
}

.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card h2 { margin: 0 0 8px; font-size: 1.05rem; }
.card p { margin: 0; color: var(--muted); font-size: .95rem; }

.feature-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 28px;
  margin: 28px 0 18px;
  padding: 0;
  list-style: none;
}

.feature-list li {
  position: relative;
  padding-left: 24px;
  color: var(--muted);
}

.feature-list li::before {
  position: absolute;
  left: 0;
  color: var(--accent);
  content: "✓";
  font-weight: 800;
}

.document {
  margin: 32px 0 80px;
  padding: 44px clamp(24px, 6vw, 64px);
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface);
}

.document h1 { font-size: clamp(2rem, 5vw, 3rem); }
.document .meta { color: var(--muted); font-size: .92rem; }
.document li { margin: 7px 0; }
.callout { margin: 24px 0; padding: 16px 18px; border-left: 4px solid var(--accent); background: var(--accent-soft); }

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 24px 0 42px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: .9rem;
}

.site-footer nav { gap: 12px; }

@media (max-width: 680px) {
  .site-header { align-items: flex-start; flex-direction: column; }
  .hero { padding-top: 34px; }
  .cards, .feature-list { grid-template-columns: 1fr; }
  .cards { margin-bottom: 48px; }
  .document { padding: 28px 20px; }
  .site-footer { align-items: flex-start; flex-direction: column; }
}