video {
  width: 100%;
  height: 100%;
  display: block;
  background: transparent;
}

body {
  margin: 0;
  width: 100%;
  height: 100vh;
  background: repeating-linear-gradient(
    135deg,
    #fff,
    #fff 6px,
    #f00 6px,
    #f00 8px
  );
}

button {
  position: absolute;
  top: 80px;
  left: 30px;
  right: 30px;
  width: calc(100% - 60px);
  bottom: 80px;
  margin: 0 auto;
    font-weight: bold;
}