html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  overflow: hidden; /* prevent scrollbars; canvas fills viewport */
  -webkit-tap-highlight-color: transparent;
}

canvas {
  display: block;
  /* Prevent iOS long-press callout and text selection/copy on the canvas */
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  user-select: none;
  -webkit-user-drag: none;
  /* Hand off all gestures to JS (prevents iOS text selection and page zoom/pan) */
  touch-action: none;
}

/* iOS Safari: prevent auto-zoom on input focus by keeping font-size >= 16px */
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
@supports (-webkit-touch-callout: none) {
  input, select, textarea {
    font-size: 16px !important;
  }
}

/* (reverted) Disabled the temporary global selection guard added previously */