customize title attribute in html code example

Example: how to stilize title property css

/* use for any tag on your page */
[data-title]:hover:after {
    opacity: 1;
    transition: all 0.1s ease 0.5s;
    visibility: visible;
}
/* box for title text */
[data-title]:after {
    content: attr(data-title);
  	/* position for title view box */
  	position: absolute;
  	bottom: -1.6em;  	
    left: 100%;
    z-index: 99999;
    visibility: hidden;
    /* optional */
    white-space: nowrap;
  	/* stilization */
    background-color: #00FF00;
    color: #111;
    font-size: 150%;
    padding: 1px 5px 2px 5px;
    box-shadow: 1px 1px 3px #222222;
    opacity: 0;
    border: 1px solid #111111;
}
[data-title] {
    position: relative;
}

/* on html page in your tags */
/* 
<a href="example.com" data-title="My site"> Link </a> with styled tooltip (bigger and with a different background color, as requested in the question)<br/>
<a href="example.com" title="My site"> Link </a> with normal tooltip
*/