:root {
  color-scheme: light;
  --ink: #17212b;
  --muted: #5c6873;
  --line: #d9dee3;
  --accent: #126b55;
  --accent-soft: #eaf4f0;
  --paper: #ffffff;
  --surface: #f5f7f8;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 16px/1.65 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

a { color: inherit; }

.site-header,
main,
footer {
  width: min(100% - 40px, 980px);
  margin-inline: auto;
}

.site-header {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
  text-decoration: none;
}

.brand img { display: block; }

nav { display: flex; gap: 24px; }

nav a {
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

nav a:hover,
nav a[aria-current="page"] { color: var(--accent); }

main { padding: 72px 0 88px; }
.narrow { max-width: 720px; }

.intro {
  max-width: 760px;
  margin-bottom: 72px;
}

.eyebrow,
.topic-meta {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}

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

h1 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(36px, 6vw, 58px);
  font-weight: 720;
}

h2 { margin: 0 0 24px; font-size: 24px; }
h3 { margin: 0 0 10px; font-size: 18px; }

.lead {
  max-width: 680px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 20px;
}

.topic-list {
  border-top: 1px solid var(--line);
}

.topic-list article {
  display: grid;
  grid-template-columns: 120px 240px 1fr;
  gap: 24px;
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
}

.topic-list p { margin: 0; color: var(--muted); }
.topic-list .topic-meta { color: var(--accent); }

.checklist {
  margin-top: 72px;
  padding: 30px 32px;
  background: var(--surface);
  border-left: 4px solid var(--accent);
}

.checklist ol { margin: 0; padding-left: 22px; }
.checklist li + li { margin-top: 8px; }

.text-link {
  display: inline-block;
  margin-top: 28px;
  color: var(--accent);
  font-weight: 650;
}

.error-page { padding-top: 120px; }

footer {
  display: flex;
  justify-content: space-between;
  padding: 24px 0 40px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 720px) {
  .site-header,
  main,
  footer { width: min(100% - 32px, 980px); }
  main { padding-top: 52px; }
  .intro { margin-bottom: 52px; }
  .topic-list article { grid-template-columns: 1fr; gap: 6px; }
  .checklist { margin-top: 52px; padding: 24px; }
  footer { flex-direction: column; gap: 4px; }
}