css diagonal border

by sthag

HTML

<div class="wrapper">
    <div class="box">
        <div class="corner"></div>
        <p>Text<br />More Text</p>
    </div>
</div>

CSS

.wrapper {
    background-color: #ddd;
    position: relative;
    height: 256px;
    margin-top: 16px;
}
.box {
    background-color: #666;
    color: #fff;
    display: table;
    position: absolute;
    top: 0;
    left: 0;
    width: 128px;
    height: 128px;
}
.corner {
    z-index: 1;
    position: absolute;
    top: 0;
    left: 0;
    border-width: 64px;
    border-top-color: transparent;
    border-right-color: crimson;
    border-bottom-color: crimson;
    border-left-color: transparent;
    border-style: solid;
}
.box p {
    z-index: 2;
    position: relative;
    display: table-cell;
    padding: 8px;
    vertical-align: bottom;
    text-align: right;
}