html, body {
  margin: 0;
  overscroll-behavior: none; /* Prevent scrolling. */
}

#canvas {
  display: block;
  margin: 0 auto;
/* Display size: scale the internal 256px canvas up to 375px */
/*<!-- Canvas dimensions are hard-coded to fit on the following mobile browsers. -->*/
/*<!-- Apple iPhone 15 Safari (393px x 695px viewport) -->*/
/*<!-- DuckDuckGo browser (393px x 650px viewport) -->*/
/*<!-- iPhone Xs Safari (375px x 634px viewport) -->*/
  width: 375px; /* CSS display width */
  height: 634px; /* CSS display height */
  image-rendering: pixelated; /* keep scaled pixels crisp for low-res art */
}