Css transition from display none to display block, navigation with subnav [duplicate]

Answer 1

You can do this with animation-keyframe rather than transition. Change your hover declaration and add the animation keyframe, you might also need to add browser prefixes for -moz- and -webkit-. See https://developer.mozilla.org/en/docs/Web/CSS/@keyframes for more detailed info.

nav.main ul ul {
    position: absolute;
    list-style: none;
    display: none;
    opacity: 0;
    visibility: hidden;
    padding: 10px;
    background-color: rgba(92, 91, 87, 0.9);
    -webkit-transition: opacity 600ms, visibility 600ms;
            transition: opacity 600ms, visibility 600ms;
}

nav.main ul li:hover ul {
    display: block;
    visibility: visible;
    opacity: 1;
    animation: fade 1s;
}

@keyframes fade {
    0% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}

    

        

            Lorem
            

                
Ipsum
                
Dolor
                
Sit
                
Amet
            
        
    

Here is an update on your fiddle. https://jsfiddle.net/orax9d9u/1/