<!doctype html>
<style>
    div {
        color: #aaa;
        font-size: 50px;
        position: relative;
        display: inline-block;
        width: 200px;
        height: 200px;
    }

    div > span { position: absolute; }

    div > span:nth-child(3) { text-decoration: underline solid coral; }
    div > span:nth-child(3) > span { text-decoration: overline dashed skyblue; }
    div > span:nth-child(3) > span  > span { text-decoration: line-through wavy green; }

</style>
<div><span>AAAA</span><span>AAAA</span><span><span><span>AAAA</span></span></span></div>