Here's a pure CSS 3 implementation (with optional JS)
The only thing you have to do is set an attribute on any div called "data-tooltip" and that text will be displayed next to it when you hover over it.
I've included some optional JavaScript that will cause the tooltip to be displayed near the cursor. If you don't need this feature, you can safely ignore the JavaScript portion of this fiddle.
If you don't want the fade-in on the hover state, just remove the transition properties.
It's styled like the title property tooltip. Here's the JSFiddle: http://jsfiddle.net/toe0hcyn/1/
HTML Example:
<div data-tooltip="your tooltip message"></div>
CSS:
*[data-tooltip] {
position: relative;
}
*[data-tooltip]::after {
content: attr(data-tooltip);
position: absolute;
top: -20px;
right: -20px;
width: 150px;
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: 12px;
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;
}
Optional JavaScript for mouse position-based tooltip location change:
var style = document.createElement('style');
document.head.appendChild(style);
var matchingElements = [];
var allElements = document.getElementsByTagName('*');
for (var i = 0, n = allElements.length; i < n; i++) {
var attr = allElements[i].getAttribute('data-tooltip');
if (attr) {
allElements[i].addEventListener('mouseover', hoverEvent);
}
}
function hoverEvent(event) {
event.preventDefault();
x = event.x - this.offsetLeft;
y = event.y - this.offsetTop;
// Make it hang below the cursor a bit.
y += 10;
style.innerHTML = '*[data-tooltip]::after { left: ' + x + 'px; top: ' + y + 'px }'
}