#canvas-container {
  position: fixed;
  inset: 0;
  z-index: -1;
  background: radial-gradient(circle at top,
      #0f2f45,
      #000000 70%);
  opacity: 0.5;
  width: 100%;
  height: 100vh;
}

#container-triang {
  position: absolute;
  left: 0;
  right: 0;
}