Web Designing

.blu:before
    {
        border-color: #538CF0 transparent;
        border-style: solid;
        border-width: 13px 13px 0;
        bottom: -18px;
        content: "";
        display: block;
        left: 40px;
        position: absolute;
        width: 0;
    }
    .blu:after
    {
        border-color: #FFFFFF transparent;
        border-style: solid;
        border-width: 13px 13px 0;
        bottom: -13px;
        content: "";
        display: block;
        left: 40px;
        position: absolute;
        width: 0;
    }
    .blu
    {
        background: none repeat scroll 0 0 #FFFFFF;
        border: 5px solid #538CF0;
        border-radius: 10px 10px 10px 10px;
        color: #333333;
        margin: 1em 0 3em;
        padding: 15px;
        position: relative;
        width: 300px;
    }

<div class="blu">
hello
</div>