:root {
  color-scheme: light;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #16202b;
  background: #f7f8fa;
}

* { box-sizing: border-box; }

body { margin: 0; line-height: 1.65; }

a { color: #075e83; text-underline-offset: 0.16em; }

/* Use valid CSS math so the shared header, content, and footer column remains centered. */
header, main, footer { width: min(calc(100% - 2rem), 52rem); margin-inline: auto; }

/* Align the header controls with the centered page column while keeping them at opposite ends of it. */
header { align-items: center; display: flex; justify-content: space-between; padding-block: 2.5rem 1.5rem; }

.brand { color: #075e83; font-weight: 800; letter-spacing: 0.03em; text-decoration: none; }

main { padding-block: 1rem 4rem; }

h1, h2 { color: #102a43; line-height: 1.2; }

h1 { font-size: clamp(2rem, 6vw, 3.25rem); margin: 0 0 1rem; }

h2 { font-size: 1.35rem; margin-top: 2.5rem; }

.lead { color: #425466; font-size: 1.2rem; max-width: 43rem; }

.app-button { background: #075e83; border-radius: 999px; color: #fff; display: inline-block; font-weight: 700; margin-left: auto; padding: 0.65rem 1.2rem; text-decoration: none; }

.app-button:hover, .app-button:focus-visible { background: #054a67; }

.card { background: #fff; border: 1px solid #dce3ea; border-radius: 1rem; margin: 1rem 0; padding: 1.25rem; }

.card h2 { margin: 0 0 0.5rem; }

.card p { margin-bottom: 0; }

.meta { color: #52606d; font-size: 0.95rem; }

li + li { margin-top: 0.5rem; }

footer { border-top: 1px solid #dce3ea; color: #52606d; font-size: 0.9rem; padding-block: 1.5rem 3rem; }

@media (prefers-color-scheme: dark) {
  :root { color: #e8eef5; background: #101820; }
  h1, h2 { color: #f3f7fb; }
  .lead, .meta, footer { color: #b7c5d3; }
  .card { background: #17232f; border-color: #334e68; }
  a, .brand { color: #60c9ee; }
  .app-button { background: #60c9ee; color: #102a43; }
  .app-button:hover, .app-button:focus-visible { background: #8ddbf4; }
  footer { border-color: #334e68; }
}