excalidraw/src/components/LibraryUnit.scss

.excalidraw {
  .library-unit {
    align-items: center;
    border: 1px solid var(--button-gray-2);
    display: flex;
    justify-content: center;
    position: relative;
    width: 63px;
    height: 63px; // match width
  }

  .library-unit__dragger {
    display: flex;
    height: 100%;
    width: 100%;
  }

  .library-unit__dragger > svg {
    filter: var(--appearance-filter);
    flex-grow: 1;
    max-height: 100%;
    max-width: 100%;
  }

  .library-unit__removeFromLibrary,
  .library-unit__removeFromLibrary:hover,
  .library-unit__removeFromLibrary:active {
    align-items: center;
    background: none;
    border: none;
    color: var(--icon-fill-color);
    display: flex;
    justify-content: center;
    margin: 0;
    padding: 0;
    position: absolute;
    right: 5px;
    top: 5px;
  }

  .library-unit__removeFromLibrary > svg {
    height: 16px;
    width: 16px;
  }

  .library-unit__pulse {
    transform: scale(1);
    animation: library-unit__pulse-animation 1s ease-in infinite;
  }

  .library-unit__adder {
    position: absolute;
    left: 50%;
    top: 50%;
    width: 20px;
    height: 20px;
    margin-left: -10px;
    margin-top: -10px;
    pointer-events: none;
  }

  .library-unit__active {
    cursor: pointer;
  }

  @keyframes library-unit__pulse-animation {
    0% {
      transform: scale(0.95);
    }

    50% {
      transform: scale(1);
    }

    100% {
      transform: scale(0.95);
    }
  }
}