style.css

html,
body {
  background-color: black;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  overflow: hidden;
}
html .slides,
body .slides,
html > .dg,
body > .dg {
  display: none;
}
@media (min-width: 1000px) {
  body {
    background-image: url('');
    background-repeat: no-repeat;
  }
  body > .dg {
    display: block;
  }
}