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

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  line-height: 1.6;
  color: #111;
  background-color: #f7f7f7;
}

main {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  background: #ffffff;
  min-height: 100vh;
}

header p {
  margin-top: 0.5rem;
  color: #555;
}

h1 {
  margin-bottom: 0.5rem;
}

h2 {
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

ul {
  padding-left: 1.25rem;
}

li {
  margin-bottom: 0.5rem;
}

a {
  color: #0366d6;
  text-decoration: none;
}

a:hover,
button:hover {
  text-decoration: underline;
}

p {
  color: #444;
}