One of our clients complained that our print stylesheet doesn’t work as the backgrounds don’t get printed.
This is a setting of the browser, not a CSS issue. In MSIE, it is part of the Advanced Options of the Internet Settings:

In Firefox, it is an option in the File – Page Setup dialogue:

A lot of people cherish the pure CSS popups technique published by Eric Meyer in the long long ago.

The only problem with these is that they are not accessible. While screen readers and browsers without CSS happily display the texts, users without a mouse have no chance to get to the content of the spans embedded in the links.

What we can do though is use Javascript to check if a mouse is available, and make our CSS dependent on a class set to the body if that is the case:

CSS:

body.mouseenabled a span{
position:absolute;
left:-999em;
}

body.mouseenabled a:hover{
color:#fff;
}

body.mouseenabled a:hover span{
position:relative;
left:0;
}

Javascript

window.onload=function()
{

if(!document.getElementById || !document.createElement){return;}
document.body.onmousemove=function()
{

if(!/bmouseenabledb/.test(document.body.className))
{

this.className+=this.className?' mouseenabled':'mousenabled';
}

}
}

See it in action here.

Benefits:

• Keyboard accessible

Drawbacks:

• The popups are visible until the user moves the mouse.
• Visitors need Javascript enabled to see the effect.