:root {
  color-scheme: light dark;
  font: 100%/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #15253e;
  background: #f1f5fb;
}
* { box-sizing: border-box; }
body { margin: 0; min-height: 100svh; display: grid; place-items: center; padding: 1.5rem; }
main { width: min(100%, 34rem); background: #fff; padding: clamp(1.5rem, 6vw, 3rem); border-top: 0.3rem solid #2461ba; border-radius: 0.5rem; box-shadow: 0 1rem 3rem #17365d0d; }
.brand { font-weight: 700; color: #2461ba; letter-spacing: 0.02em; margin: 0 0 2rem; }
h1 { font-size: clamp(1.65rem, 5vw, 2.25rem); line-height: 1.2; letter-spacing: -0.035em; margin: 0 0 1rem; }
p { margin: 0 0 1rem; }
p:last-child { margin-bottom: 0; }
.secondary { color: #4c5b72; }
a { color: #1d58a7; text-underline-offset: 0.2em; display: inline-block; padding: 0.5rem 0; }
a:focus-visible { outline: 0.2rem solid currentColor; outline-offset: 0.2rem; }
@media (prefers-color-scheme: dark) {
  :root { color: #e9f0fc; background: #101a2b; }
  main { background: #18263d; border-top-color: #84b9ff; box-shadow: none; }
  .brand, a { color: #96c3ff; }
  .secondary { color: #bdcbe0; }
}