*[data-tooltip] {
    position: relative;
}

*[data-tooltip]::after {
    content: attr(data-tooltip);
    
    position: absolute;
    top: -25px;
    left: -3px;
    width: 400px;
    
    pointer-events: none;
    opacity: 0;
    -webkit-transition: opacity .15s ease-in-out;
    -moz-transition: opacity .15s ease-in-out;
    -ms-transition: opacity .15s ease-in-out;
    -o-transition: opacity .15s ease-in-out;
    transition: opacity .15s ease-in-out;

    display: block;
    font-size: 14px;
    line-height: 16px;
    background: #fefdcd;
    padding: 2px 2px;
    border: 1px solid #c0c0c0;
    box-shadow: 2px 4px 5px rgba(0, 0, 0, 0.4);
}

*[data-tooltip]:hover::after {
    opacity: 1;
}

/* This part is for example purposes only.
 div {
    margin-top: 100px;
    background: #0a0;
    width: 200px;
    height: 20px;
}*/