#tooltip {
    text-align: center;
    color: #fff;
    background: #111;
    position: absolute;
    z-index: 999999;
    padding: 15px;
}

    #tooltip:after /* triangle decoration */ {
        width: 0;
        height: 0;
        border-left: 10px solid transparent;
        border-right: 10px solid transparent;
        border-top: 10px solid #111;
        content: '';
        position: absolute;
        left: 50%;
        bottom: -10px;
        margin-left: -10px;
    }

    #tooltip.top:after {
        border-top-color: transparent;
        border-bottom: 10px solid #111;
        top: -20px;
        bottom: auto;
    }

    #tooltip.left:after {
        left: 10px;
        margin: 0;
    }

    #tooltip.right:after {
        right: 10px;
        left: auto;
        margin: 0;
    }