CSS transition from `display: none` on class change?

Question

I\'ve started using transitions to \"modernise\" the feel of a site. So far, :hover transitions are working great. Now I\'m wondering if it\'s possible to trigg

Answer 1

The answer provided by @MarcoK including the comments shows already the right direction. Setting display property hinders transition.
A better practice is though to put the unprefixed (standards) version after the browser-vendor prefixed ones, in order to be future-proof. The latter properties overwrite the former.
Other improvements:

• As @Charmander pointed out, -ms-transition isn't supported by any Internet Explorer
• There's also Opera's vendor prefixed -o-transition for Op 10.5-12 & Op Mobile 10-12, which currently is probably supported by less than .1% of global browser. I'll put it in for completion

CSS:

#myelem {
    opacity: 0;
    -webkit-transition: opacity .4s ease-in;
       -moz-transition: opacity .4s ease-in;
         -o-transition: opacity .4s ease-in;
            transition: opacity .4s ease-in;
}
#myelem.show {
    opacity: 1;
    -webkit-transition: opacity .4s ease-out;
       -moz-transition: opacity .4s ease-out;
         -o-transition: opacity .4s ease-out;
            transition: opacity .4s ease-out;
}​