Ghost/ghost/admin/assets/sass/helpers/animations.scss

//
// Fade in
// --------------------------------------------------

@include keyframes(fade-in) {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}
.fade-in {
    @include animation(fade-in 0.2s);
}

@include keyframes(fade-in-snap) {
    to {
        opacity: 1;
    }
}


//
// Fade out
// --------------------------------------------------

@include keyframes(fade-out) {
    from {
        opacity: 1;
    }
    to {
        opacity: 0;
    }
}
.fade-out {
    @include animation(fade-out 0.5s);
}