* {
  padding: 0;
  margin: 0;
}

html, body, main {
  height: 100%;
}

body {
  position: fixed;
  top: 0;
  left: 0;
  z-index: -1;
  width: 100vw;
  height: 100vh;
  padding: 0;
  margin: 0;
}

main {
  display: flex;
  justify-content: center;
  align-items: center;
}