debugger-app/modules/debug-view-sk/debug-view-sk.scss

debug-view-sk {
  // copied this trick from https://css-tricks.com/how-to-stack-elements-in-css/
  .grid {
    display: grid;
    grid-template-columns: 1fr;
    grid-template-rows: 1fr;
  }

  // Put the crosshair canvas directly on top of the debug canvas by putting it in the same
  // grid cell
  canvas {
    grid-area: 1 / 1 / 2 / 2;
  }

  // Four sizing options for the debug canvas.
  // if one of these is applied to the debug canvas, it must also be applied
  // to the crosshair canvas.
  .bottom {
    width: auto;
    height: 82vh;
  }

  .fit {
    max-width: 100%;
    max-height: 82vh;
    width: auto;
    height: auto;
  }

  .natural {
    width: auto;
    height: auto;
  }

  .right {
    width: 100%;
    height: auto;
  }

  .light-checkerboard {
    border: solid lightgray 1px;
    background-position:
      0 0,
      10px 10px;
    background-size: 20px 20px;
    background-image:
      linear-gradient(45deg, #eee 25%, transparent 25%, transparent 75%, #eee 75%, #eee 100%),
      linear-gradient(45deg, #eee 25%, white 25%, white 75%, #eee 75%, #eee 100%);
  }

  .dark-checkerboard {
    border: solid lightgray 1px;
    background-position:
      0 0,
      10px 10px;
    background-size: 20px 20px;
    background-image:
      linear-gradient(45deg, #555 25%, transparent 25%, transparent 75%, #555 75%, #555 100%),
      linear-gradient(45deg, #555 25%, #222 25%, #222 75%, #555 75%, #555 100%);
  }

  button {
    border: none;
    background-color: transparent;
    margin: 5px;
  }

  img {
    opacity: 0.5; /* I have black icons but want grey ones */
  }
}