Fade In / Fade Out (CSS3)

fading.css

[js-animate="fadeout"] {
    transition: opacity .5s ease-out, height .5s;
    -o-transition: opacity .5s ease-out, height .5s;
    -moz-transition: opacity .5s ease-out, height .5s;
    -webkit-transition: opacity .5s ease-out, height .5s;
    opacity: 0; height: 0px !important;
}

[js-animate="fadein"] {
    transition: opacity .5s ease-out, height .5s;
    -o-transition: opacity .5s ease-out, height .5s;
    -moz-transition: opacity .5s ease-out, height .5s;
    -webkit-transition: opacity .5s ease-out, height .5s;
    opacity: 1;
    height: inherit;
}