Reversing a CSS3 animation on click

Question

According to a book, the example below should fade-in and -out the menu, but Instead the menu disappears immediately. I believe the problem is that display: none take effect too early somehow, but I am not sure since it says display: block in the animation.

What can I do to make the grey div fade out smooth instead of just disappearing? A solution only using CSS for the animation would be preferred.

CSS

a {
    color: white;
    text-align: center;
}

.bar {
    height: 20px;
    background: red;
}

.div {
    background: silver;
    padding: 10px;
}

@-webkit-keyframes fade {
  0% {
    opacity: 0;
    display: block;
  }

  100% {
    opacity: 1;
    display: block;
  }
}

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

  100% {
    opacity: 1;
    display: block;
  }
}

.hidden {
    display: none;
    -webkit-animation: fade 2s reverse;
    animation: fade 2s reverse;
}

.shown {
    display: block;
    -webkit-animation: fade 2s;
    animation: fade 2s;
}

HTML

<div class="bar">
    <a href="#" class="click">Click Me</a>
    <div class="div shown">
        <p>Hello</p>
    </div>
</div>

jQuery

$(function() {
    $div = $(".div");

    var menu = function () {
        if ( $div.hasClass("shown")) {
            $div.removeClass("shown");
            $div.addClass("hidden");
        } else {
            $div.removeClass("hidden");
            $div.addClass("shown");
        }

    }

    menu();

    $(".click").bind("click", menu);

});

Fiddle: http://jsfiddle.net/hFdbt/1/

Answer 1

As i said in my comment, you might just aswell use jquery for it.

jQuery

$(".click").on("click", function() {
    $(".div").fadeToggle("slow");
});

HTML

<div class="bar">
    <a href="#" class="click">Click Me</a>
    <div class="div shown">
        <p>Hello</p>
    </div>
</div>

Css

a {
    color: white;
    text-align: center;
}

.bar {
    height: 20px;
    background: red;
}

.div {
    background: silver;
    padding: 10px;
    display: none;
}

New fiddle: http://jsfiddle.net/QvpS3/

Answer 2

Since you can not transition on the display element (think of it as a boolean or enum, there is nothing but "true" and "false", as in there is no true.5 ), you must use some other method to hide the element.

In this fiddle ( http://jsfiddle.net/3n1gm4/Q5TBN/ ) I've used the max-height property and overflow: hidden along with transition to set the delay.

.hidden {
    -webkit-animation: fade 2s reverse;
    animation: fade 2s reverse;

    -webkit-transition: 0s all 2s; /* delay this the duration of the animation */
    transition-delay: 0s all 2s;
    max-height: 0;
    padding: 0;

    overflow: hidden;

}

.shown {
    -webkit-animation: fade 2s;
    animation: fade 2s;
    max-height: 5000px; /* some number way bigger than it will ever be to avoid clipping */
}

credits: Transitions on the display: property