CSS3 Ribbon

CSS3でリボン

HTML

<h1 class="ribbon">CSS3 RIBBON</h1>

CSS

.ribbon{
    padding:1em;
    position:relative;
    display:inline-block;
    background:#333;
    color:#fff;
}
.ribbon:after{
    content:'';
    position:absolute;
    bottom:-10px;
    right:-10px;
    z-index:-1;
    border-width:10px;
    border-style:solid;
    border-color:transparent transparent transparent #000;
}