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

body {
  font-family: system-ui, sans-serif;
  margin: 0;
  padding: 0;
  color: #1a1a1a;
  background: #fff;
}

a { color: #2563eb; }

h1, h2, h3 { line-height: 1.2; }

header {
  padding: 1rem 2rem;
  border-bottom: 1px solid #e5e5e5;
  display: flex;
  gap: 2rem;
}

header a {
  color: inherit;
  text-decoration: none;
  font-weight: 500;
}

header a:hover { text-decoration: underline; }

main {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem;
}