/* Mirrors design-direction.md: monochrome, iOS grouped surfaces, rounded type.
   The web has no semantic system colours, so these are iOS's own values. */
:root {
  color-scheme: light dark;
  --bg: #f2f2f7;
  --card: #ffffff;
  --label: #000000;
  --secondary: rgba(60, 60, 67, 0.6);
  --tertiary: rgba(60, 60, 67, 0.3);
  --separator: rgba(60, 60, 67, 0.29);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --card: #1c1c1e;
    --label: #ffffff;
    --secondary: rgba(235, 235, 245, 0.6);
    --tertiary: rgba(235, 235, 245, 0.3);
    --separator: rgba(84, 84, 88, 0.6);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--label);
  font-family: ui-rounded, "SF Pro Rounded", system-ui, -apple-system, "Segoe UI", sans-serif;
  font-variant-numeric: tabular-nums;
  font-size: 17px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 48px 16px 32px;
}

a { color: inherit; text-underline-offset: 3px; }

header.site {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 48px;
}
header.site a { text-decoration: none; font-weight: 700; }
header.site nav a { font-weight: 400; color: var(--secondary); margin-left: 16px; }

h1 { font-size: 40px; line-height: 1.1; margin: 0 0 16px; letter-spacing: -0.01em; }
h2 { font-size: 22px; margin: 32px 0 8px; }
h3 { font-size: 17px; margin: 24px 0 4px; }
p, li { color: var(--secondary); }
p.lead { font-size: 20px; color: var(--label); }
strong { color: var(--label); }

.card {
  background: var(--card);
  border-radius: 16px;
  padding: 20px;
  margin: 24px 0;
}
.card ul { margin: 0; padding-left: 20px; }
.card li + li { margin-top: 8px; }

.hero-number {
  font-size: 88px;
  font-weight: 700;
  line-height: 1;
  color: var(--label);
}
.hero-caption { color: var(--secondary); margin: 4px 0 0; }

.badge {
  display: inline-block;
  border: 1px solid var(--separator);
  border-radius: 999px;
  padding: 6px 14px;
  color: var(--secondary);
  font-size: 15px;
}

footer {
  border-top: 1px solid var(--separator);
  margin-top: 48px;
  padding-top: 16px;
  font-size: 13px;
  color: var(--tertiary);
}
footer a { color: var(--secondary); margin-right: 16px; }