body, html {
  margin: 0; padding: 0; background: #000; overflow: hidden;
}
.container {
  position: relative; width: 100vw; height: 100vh;
  display: flex; justify-content: center; align-items: center;
}
canvas {
  position: absolute; top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  max-width: 90vw;
  max-height: 90vh;
}
#imageCanvas { cursor: pointer; }
#particleCanvas, #glitchCanvas { pointer-events: none; }