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

body {
  background: #000;
}

.frame {
  height: 100vh;
  width: 100vw;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.cover {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  display: block;
}