<meta charset="utf-8">
<title>Уроки CSS. Часть 3</title>
<link rel="stylesheet" href="main.css">
<div class="container">Текст по центру</div>
.container {
.container {margin: 20px;
width:150px;
height: 80px;
background: #444;
border-radius: 5px;
position:relative;
color: #fff;
display: table-cell;
vertical-align: middle;
text-align: center;
}
.container:after {
content: '';
position:absolute;
border-top: 10px solid #444;
border-left: 10px solid transparent;
border-right: 10px solid transparent;
bottom: -10px;
left: 66px;
}