g to the number of mask layers.">
    <style type="text/css">
      div {
        background-color: blue;
        position: absolute;
        margin: 0px;
        padding: 0px;
        width: 100px;
        height: 100px;
        top: 10px;
      }

      div.add {
        left: 10px;
        mask-composite: add;
        mask-image: url(support/blue-100x50-transparent-100x50.svg),
                    url(support/blue-100x50-transparent-100x50.svg),
                    url(support/blue-100x50-transparent-100