Responsive CSS square with centered text

by Yolanda Robles

HTML

<div class='square-box'>
    <div class='square-content'>
        <div>
            <span>Aspect ratio 1:1</span>
        </div>
    </div>
</div>

CSS

.square-box {
    position: relative;
    width: 50%;
    overflow: hidden;
    background: #4679BD;
}
.square-box:before {
    content:"";
    display: block;
    padding-top: 100%;
}
.square-content {
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    color: white;
}
.square-content div {
    display: table;
    width: 100%;
    height: 100%;
}
.square-content span {
    display: table-cell;
    text-align: center;
    vertical-align: middle;
    color: white
}