Change Highlighter

@import url('http://1119s.wdfiles.com/local--code/change-highlighter/1');

ins::before,
del::before {
    content: "";
    display: inline-block;
    width: 1em;
    height: 3em;
    position: absolute;
    transform: translate(-2em, -0.8em);
}
ins::before {
    background: blue;
}
del::before {
    background: red;
}