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

html, body {
  height: 100%;
  background: #fff;
}

main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 1.5rem;
}

img {
  width: 100%;
  max-width: 600px;
  height: auto;
  display: block;
}