Why does my ::before element cover background I set for link?

Question

How do I make ::before stay "under" link's background?

.container{
    max-width: 1200px;
    padding: 0 15px;
    margin: 0 auto;
}

.block{
    max-width: 500px;
    height: 200px;
    background: #000;
    text-align: center;
}

.link{
    display: inline-block;
    position: relative;
    color: #fff;
    text-decoration: none;
    padding-top: 150px;
    background: red;
}

.link::before{
    content: "";
    position: absolute;
    width: 99px;
    height: 99px;
    top: 20%;
    right: 0%;
    background: #fff;
    border-radius: 50%;
}

<div class="container block">
    <a href="#" class="link">Link text</a>
</div>