How to slide toggle a pseudo element?

Question

As you can see in this jsfiddle, when you click the menu button, the little triangle that points to the button is only shown after the animation has finished. I'd like the animation to start with the pseudo element and only then proceed to the drop-menu element. How can I accomplish this?

A solution doesn't necessarily have to use javascript, CSS3 will be most welcome, I'm not worried about compatibility issues.

Answer 1

You can try this - DEMO

.drop-menu {
    display: none;
    position: relative;
    height: 60px;
    top: -20px;
}

.drop-menu ul::before {
    content: '';
    width: 0;
    height: 0;
    position: absolute;
    top: -30px;
    left: 30px;
    border-width: 15px;
    border-color: transparent transparent red transparent;
    border-style: solid;
}

.drop-menu ul {
    background-color: red;
    position: relative;
    top: 20px;
    z-index: 999;
}