body {
  background-color: black;
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  overflow: hidden;
  width: 100vw;
  height: 100vh;
}

div.screen {
  width: 800px;
  height: 600px;
  position: absolute;
  left: 50%;
  top: 50%;
  translate: -50% -50%;
  box-shadow: 0 0 64px 4px #fff4;
  border-radius: 8px;
  overflow: hidden;
}

div.screen iframe {
  display: inline-block;
  width: 100%;
  height: 100%;
  border: none;
  margin: 0;
  padding: 0;
  font-size: 16px;
}

div.screen div.crt {
  display: inline-block;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: repeating-linear-gradient(
    0deg,
    #0006 0px,
    #0006 1px,
    #0000 1px,
    #0000 2px
  );
  background-repeat: repeat;
  background-position: 0 0;
  background-size: 2px;
  user-select: none;
  pointer-events: none;
  z-index: 9000;
}