html,
body {
  margin: 0;
  height: 100%;
  width: 100%;
}

main {
  height: 100%;
  width: 100%;
}

section {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.responsive {
  max-width: 100%;
  height: auto;
}