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

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  width: 100%;
  background: black !important;
  overflow: hidden;
}
#container {
  position: relative;
  height: 100%;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}
img, video {
  max-width: 100%;
  max-height: 100%;
  width: 100%;
  height: 100%;
  object-fit: contain;
  position: absolute;
  top: 0;
  left: 0;
}
#overlay {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background: black;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.5s;
}