*, *::before, *::after { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Oxygen, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 2rem 1.25rem;
}

main {
  max-width: 640px;
  width: 100%;
  margin: auto;
  text-align: center;
}

h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 0.5rem;
}

.subtitle {
  font-size: 1.125rem;
  opacity: 0.7;
  margin: 0;
}

footer {
  max-width: 640px;
  width: 100%;
  margin: 0 auto;
  text-align: center;
  font-size: 0.875rem;
  opacity: 0.6;
  padding-top: 2rem;
}

footer a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

footer a:hover { opacity: 0.8; }