:root {
  color-scheme: light dark;
  --fg: #16202b;
  --bg: #ffffff;
  --muted: #5a6672;
  --rule: #dde3ea;
}

@media (prefers-color-scheme: dark) {
  :root {
    --fg: #e6ecf2;
    --bg: #141a20;
    --muted: #9aa7b4;
    --rule: #2b353f;
  }
}

body {
  margin: 0 auto;
  padding: 2rem 1rem 4rem;
  max-width: 48rem;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  line-height: 1.6;
  color: var(--fg);
  background: var(--bg);
}

/* Banner artwork has a light background baked in, so it sits on its own
   white panel -- deliberate in dark mode rather than a floating white slab. */
.banner {
  display: block;
  width: 100%;
  max-width: 30rem;
  height: auto;
  background: #fff;
  border-radius: 10px;
  padding: 0.5rem;
  box-sizing: border-box;
}

.tagline {
  color: var(--muted);
  margin-top: 0.75rem;
}

h2 {
  margin-top: 2.5rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--rule);
  font-size: 1.15rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--muted);
}

ul { padding-left: 1.2rem; }
li { margin-bottom: 0.6rem; }

a { color: #1f6fb2; }
@media (prefers-color-scheme: dark) { a { color: #6ab4ee; } }

footer {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  font-size: 0.9rem;
  color: var(--muted);
}

/* Heading text is carried by the banner image's alt attribute. */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}