.flipbook-page-item {
    border-radius: 50%;

    background-color: #fff;

    -webkit-mask-composite: destination-out;
    -webkit-mask: url(data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 20 20"><g stroke="black" stroke-width="4"><line x1="10" y1="20" x2="10" y2="0"/><line x1="0" y1="10" x2="20" y2="10"/></g></svg>) no-repeat 0/100% 20px, linear-gradient(#fff,#fff);
    -webkit-mask-repeat: no-repeat;
    -webkit-mask-position: center;
    -webkit-mask-composite: exclude;
}

/*.flipbook-page-item:before {
    content: url(data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="50" height="50" viewBox="0 0 101 101"><path fill-rule="evenodd" fill="rgb(255,255,255)" d="M28.999,47.999 L28.999,50.999 L49.0,50.999 L49.0,71.0 L52.0,71.0 L52.0,50.999 L71.0,50.999 L71.0,47.999 L52.0,47.999 L52.0,28.999 L49.0,28.999 L49.0,47.999 L28.999,47.999 Z"/></svg>);
    display: block;
    width: 50px;
    height: 50px;
}*/

.htmlLayer img {
    cursor: pointer;
}