"assert" content="In vertical mixed, the ic unit is equal to the used vertical advance measure of the 水 (CJK water ideograph, U+6C34) glyph found in the font used to render it.">
<style>
@font-face {
    font-family: IcTestFullWidth;
    src: url(resources/IcTestFullWidth.woff2);
}

span {
    font: 20px IcTestFullWidth;
    background: green;
    color: green;
    left: 0; right: 0;
    position: absolute;
}

div {
    font: 20px IcTestFullWidth;
    background: red;
    color: red;
    position: relativ