piskel/src/css/tools.css

.tool-icon {
  position : relative;
  cursor : pointer;
  width: 46px;
  height: 46px;
  margin: 1px;
  background-color: #3a3a3a;
}

.tool-icon.selected {
  cursor: default;
  background-color: #444;
}

.tool-icon.selected:before {
  content:"";
  position : absolute;
  height : 100%;
  width : 100%;
  border: 3px solid var(--highlight-color);
  box-sizing: border-box;
}

.tool-icon:hover {
  background-color: #444;
}

/*
 * Tool cursors:
 */

.tool-paint-bucket .drawing-canvas-container:hover,
.tool-colorswap .drawing-canvas-container:hover {
  cursor: url(../img/cursors/paint-bucket.png) 14 14, pointer;
}

.tool-vertical-mirror-pen .drawing-canvas-container:hover {
  cursor: url(../img/cursors/vertical-mirror-pen.png) 5 15, pointer;
}

.tool-pen .drawing-canvas-container:hover {
  cursor: url(../img/cursors/pen.png) 1 14, pointer;
}

.tool-dithering .drawing-canvas-container:hover {
  cursor: url(../img/cursors/dither.png) 1 14, pointer;
}

.tool-lighten .drawing-canvas-container:hover {
  cursor: url(../img/cursors/lighten.png) 1 15, pointer;
}

.tool-eraser .drawing-canvas-container:hover {
  cursor: url(../img/cursors/eraser.png) 3 14, pointer;
}

.tool-stroke .drawing-canvas-container:hover {
  cursor: url(../img/cursors/stroke.png) 1 14, pointer;
}

.tool-rectangle .drawing-canvas-container:hover {
  cursor: url(../img/cursors/rectangle.png) 5 15, pointer;
}

.tool-circle .drawing-canvas-container:hover {
  cursor: url(../img/cursors/circle.png) 5 15, pointer;
}

.tool-move .drawing-canvas-container:hover {
  cursor: url(../img/cursors/hand.png) 7 7, pointer;
}

.tool-rectangle-select .drawing-canvas-container:hover,
.tool-lasso-select .drawing-canvas-container:hover {
  cursor: crosshair;
}

.tool-shape-select .drawing-canvas-container:hover {
  cursor: url(../img/cursors/wand.png) 10 5, pointer;
}

.tool-colorpicker .drawing-canvas-container:hover {
  cursor: url(../img/cursors/dropper.png) 2 15, pointer;
}

.swap-colors-button {
  position: relative;
  top: 50px;
  left: 6px;
  height: 18px;
  width: 18px;

  opacity : 0.3;

  cursor : pointer;
}

.swap-colors-button:hover {
  opacity : 1;
}

.tool-color-picker {
  position:relative;
}

.tool-color-picker:nth-child(1) {
  z-index : 100;
}

.tool-color-picker:nth-child(2) {
  z-index : 90;
  margin-top: 25px;
  margin-left:-20px;
}

.tool-color-picker input {
  width: 16px;
  height: 16px;
  text-indent: -10000px;
  border: 1px solid black;
  background: white;
  cursor: pointer;
  position : relative;
  top: 10px;
  margin-left: 2px;
}

.tool-color-picker .secondary-color-picker {
  top : 18px;
  margin-left: 0;
}

.palette-wrapper {
  margin-top: 10px;
  margin-left: 10px;
}

.palette-color[data-color=TRANSPARENT] {
  position: relative;
  top: 10px;
  left: 10px;
  background-color: white;
  height : 16px;
  width : 16px;
  border: 2px solid #000;
  background-size: 16px 16px;
  background-position: 0 0;
  background-image: -webkit-gradient(
    linear,
    left top,
    right bottom,
    color-stop(0, #fff),
    color-stop(0.45, #fff),
    color-stop(0.5, #ff0000),
    color-stop(0.55, #fff),
    color-stop(1, #fff)
  );
  background-image: -moz-linear-gradient(
      left top,
      #fff 0%,
      #fff 45%,
      #f00 50%,
      #fff 55%,
      #fff 100%
  );
}