A CodePen by Seth Abbott. CSS Swinging Panel Menu - A simple, clean pure CSS menu that uses keyframe animation to create a "swining panel" effect for sub nav. I am having trouble getting it to work in Opera but performs well in Chrome, Safari and Firefox
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
padding: 30px;
font-family: "Helvetica Neue", helvetica, arial;
background: url('http://subtlepatterns.com/patterns/white_carbonfiber.png');
}
#container {
position: relative;
width: 940px;
}
#container:after {
content: "";
display: block;
clear: both;
height: 0;
}
#menu {
position: relative;
float: left;
width: 100%;
padding: 0 20px;
border-radius: 3px;
box-shadow: inset 0 1px 1px rgba(255,255,255,.5), inset 0 -1px 0 rgba(0,0,0,.15), 0 1px 3px rgba(0,0,0,.15);
background: #ccc;
}
#menu, #menu ul {
list-style: none;
}
#menu > li {
float: left;
position: relative;
border-right: 1px solid rgba(0,0,0,.1);
box-shadow: 1px 0 0 rgba(255,255,255,.25);
perspective: 1000px;
}
#menu > li:first-child {
border-left: 1px solid rgba(255,255,255,.25);
box-shadow: -1px 0 0 rgba(0,0,0,.1), 1px 0 0 rgba(255,255,255,.25);
}
#menu a {
display: block;
position: relative;
z-index: 10;
padding: 13px 20px 13px 20px;
text-decoration: none;
color: rgba(75,75,75,1);
line-height: 1;
font-weight: 600;
font-size: 12px;
letter-spacing: -.05em;
background: transparent;
text-shadow: 0 1px 1px rgba(255,255,255,.9);
transition: all .25s ease-in-out;
}
#menu > li:hover > a {
background: #333;
color: rgba(0,223,252,1);
text-shadow: none;
}
#menu li ul {
position: absolute;
left: 0;
z-index: 1;
width: 200px;
padding: 0;
opacity: 0;
visibility: hidden;
border-bottom-left-radius: 4px;
border-bottom-right-radius: 4px;
background: transparent;
overflow: hidden;
transform-origin: 50% 0%;
}
#menu li:hover ul {
padding: 15px 0;
background: #333;
opacity: 1;
visibility: visible;
box-shadow: 1px 1px 7px rgba(0,0,0,.5);
animation-name: swingdown;
animation-duration: 1s;
animation-timing-function: ease;
}
@keyframes swingdown {
0% {
opacity: .99999;
transform: rotateX(90deg);
}
30% {
transform: rotateX(-20deg) rotateY(5deg);
animation-timing-function: ease-in-out;
}
65% {
transform: rotateX(20deg) rotateY(-3deg);
animation-timing-function: ease-in-out;
}
100% {
transform: rotateX(0);
animation-timing-function: ease-in-out;
}
}
#menu li li a {
padding-left: 15px;
font-weight: 400;
color: #ddd;
text-shadow: none;
border-top: dotted 1px transparent;
border-bottom: dotted 1px transparent;
transition: all .15s linear;
}
#menu li li a:hover {
color: rgba(0,223,252,1);
border-top: dotted 1px rgba(255,255,255,.15);
border-bottom: dotted 1px rgba(255,255,255,.15);
background: rgba(0,223,252,.02);
}
<div id="container">
<ul id="menu">
<li><a href="#">About Me</a>
<ul>
<li><a href="#">Lorem ipsum dolor</a></li>
<li><a href="#">Maecenas lacinia sem</a></li>
<li><a href="#">Suspendisse fringilla</a></li>
</ul>
</li>
<li><a href="#">Portfolio</a>
<ul>
<li><a href="#">Lorem ipsum dolor</a></li>
<li><a href="#">Maecenas dignissim fermentum luctus</a></li>
<li><a href="#">Suspendisse fringilla</a></li>
<li><a href="#">Lorem ipsum dolor</a></li>
<li><a href="#">Maecenas lacinia sem</a></li>
<li><a href="#">Suspendisse fringilla</a></li>
</ul>
</li>
<li><a href="#">Clients</a>
<ul>
<li><a href="#">Lorem ipsum dolor</a></li>
<li><a href="#">Maecenas lacinia sem</a></li>
<li><a href="#">Suspendisse fringilla</a></li>
</ul>
</li>
<li><a href="#">Contact Me</a>
<ul>
<li><a href="#">Lorem ipsum dolor</a></li>
<li><a href="#">Maecenas dignissim fermentum luctus</a></li>
<li><a href="#">Suspendisse fringilla</a></li>
</ul>
</li>
<li><a href="#">Support</a></li>
</ul>
</div>