*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-text: #1a1a1a;
  --color-bg: #ffffff;
  --color-link: #0055aa;
  --color-muted: #666666;
  --max-width: 720px;
  --font: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
}

html { font-size: 100%; }
body {
  font-family: var(--font);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1rem;
}

a { color: var(--color-link); }
h1, h2, h3 { line-height: 1.2; margin-top: 2rem; margin-bottom: 0.5rem; }
h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
p, ul, ol { margin-bottom: 1rem; }
ul, ol { padding-left: 1.5rem; }
img { max-width: 100%; height: auto; display: block; }

header { margin-bottom: 3rem; }
header nav { display: flex; align-items: center; gap: 2rem; }
header nav ul { list-style: none; display: flex; gap: 1rem; padding: 0; }

main form div { margin-bottom: 1rem; }
main form label { display: block; font-weight: 600; margin-bottom: 0.25rem; }
main form input, main form textarea { width: 100%; padding: 0.5rem; font-size: 1rem; border: 1px solid #ccc; border-radius: 4px; }
main form button { padding: 0.75rem 1.5rem; font-size: 1rem; background: var(--color-link); color: #fff; border: none; border-radius: 4px; cursor: pointer; }
main form button:disabled { opacity: 0.5; cursor: not-allowed; }

footer { margin-top: 4rem; padding-top: 2rem; border-top: 1px solid #eee; color: var(--color-muted); font-size: 0.875rem; }