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

body, html {
  width: 100%;
  height: 100%;
  background-color: black;
}

.main-frame {
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

video {
  max-width: 100%;
  height: auto;
}