* {
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
}

body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
}

main {
  max-width: 992px;
  margin: 0 auto;
  padding: 20px;
}

h1, h2, h3 {
  color: #333;
}