纯CSS实现的3D简洁按钮设计

<nav>

<ul class="nav">

<li><a href="#" class="icon-home"></a></li>

<li><a href="#" class="icon-cog"></a></li>

<li><a href="#" class="icon-cw"></a></li>

<li><a href="#" class="icon-location"></a></li>

</ul>
 </nav>

@font-face {
font-family: 'fontello';
src: url('../fonts/fontello.eot');
src: url('../fonts/fontello.eot?#iefix') format('embedded-opentype'),
url('../fonts/fontello.woff') format('woff'),
url('../fonts/fontello.ttf') format('truetype'),
url('../fonts/fontello.svg#fontello') format('svg');
font-weight: normal; font-style: normal;
}
[class*=" icon-"] {
font-family: 'fontello';
font-style: normal;
font-size: 3em;
speak: none;
}
.icon-home:after     { content: "\2302"; }
.icon-cog:after      { content: "\2699"; }
.icon-cw:after       { content: "\27f3"; }
.icon-location:after { content: "\e724"; }

.nav {
list-style: none;
text-align: center;
}
.nav li {
position: relative;
display: inline-block;
margin-right: -4px;
}

.nav a {
display: block;
background-color: #f7f7f7;
background-image: -webkit-gradient(linear, left top, left bottom, from(#f7f7f7), to(#e7e7e7));
background-image: -webkit-linear-gradient(top, #f7f7f7, #e7e7e7);
background-image: -moz-linear-gradient(top, #f7f7f7, #e7e7e7);
background-image: -ms-linear-gradient(top, #f7f7f7, #e7e7e7);
background-image: -o-linear-gradient(top, #f7f7f7, #e7e7e7);    color: #a7a7a7;
margin: 36px;   width: 144px;
height: 144px;
position: relative;
text-align: center;
line-height: 144px;
border-radius: 50%;
box-shadow: 0px 3px 8px #aaa, inset 0px 2px 3px #fff;
}

.nav a:hover{
text-decoration: none;
color: #555;
background: #f5f5f5;
}