body {
  margin: 0;
  background: #fff;
  color: #222;
  font: 16px/1.6 system-ui, sans-serif;
}

main {
  max-width: 640px;
  margin: 48px auto;
  padding: 0 24px;
}

h1 {
  margin: 0 0 16px;
  font-size: 28px;
  line-height: 1.3;
}

a { color: #0645ad; }
a:focus-visible { outline: 2px solid currentColor; outline-offset: 4px; }