From the hint.css homepage:
data-*attribute, pseudo elements, content property and CSS3 transitions to create the tooltips. hint.css uses BEM naming convention particularly for the modifiers.
The usage is simple. Download one of the 2 library versions to your project and include the CSS file in the
<head> of your page.
Then, the tooltip text is passed using the
data-hint attribute on the element.
Hello Sir, <span class="hint hint--bottom" data-hint="Thank you!">hover me.</span>
Check out the homepage for more details and demos in action.