OSX button styles

HTML

<button class="osx-btn">Button</button>
<div class="osx-btn-group">
    <button class="osx-btn">A</button>
    <button class="osx-btn">B</button>
    <button class="osx-btn">C</button>
    <button class="osx-btn">D</button>
    <button class="osx-btn icon">&spades;</button>
    <button class="osx-btn icon">&hearts;</button>
</div>
<button class="osx-btn btn-dropdown">View</button>
<div class="osx-btn-split">
    <button class="osx-btn icon">&larr;</button>
    <button class="osx-btn icon">&rarr;</button>
</div>

CSS

.osx-btn {
    color: #333;
    text-shadow: 0 1px 0 rgba(255, 255, 255, 0.8);
    border-radius: 4px;
    outline: none;
    border: 1px solid #7F7F7F;
    border-top: 1px solid #7E7E7E;
    border-bottom: 1px solid #6F6F6F;
    box-shadow: inset 0 1px 0 #F6F6F6, 0 1px 0 #CDCDCD;
    background: linear-gradient(to bottom, #F1F1F1 0%, #C2C2C2 100%);
    -webkit-font-smoothing: anti-aliased;
    padding: 5px 6px 4px;
    font-size: 13px;
    font-family:"Helvetica Neue", Helvetica, Arial, sans-serif;
    -webkit-transition: all 0.1s ease;
}
.osx-btn.icon {
    font-size: 18px;
    padding: 0 6px 2px;
}
.osx-btn.active, .osx-btn:active {
    color: white;
    z-index: 2;
    text-shadow: 0 1px 0 rgba(0, 0, 0, 0.5);
    border: 1px solid #595959;
    border-top: 1px solid #575757;
    border-bottom: 1px solid #858585;
    box-shadow: 0 1px 0 #CDCDCD;
    background: linear-gradient(to bottom, #676767 0%, #9A9A9A 100%);
}
.osx-btn-group > .osx-btn {
    position: relative;
    margin: 0 0 0 -5px;
    border-radius: 0;
}
.osx-btn-group > .osx-btn:first-child {
    border-radius: 3px 0 0 3px;
    margin: 0;
}
.osx-btn-group > .osx-btn:last-child {
    border-radius: 0 3px 3px 0;
}
.osx-btn.btn-dropdown:after {
    display: inline-block;
    content:'▼';
    color: #555;
    text-shadow: 0 1px 0 rgba(255, 255, 255, 1), 0 -2px 0 rgba(0, 0, 0, 1);
    font-size: 18px;
    width: 14px;
    height: 12px;
    margin: 0 0 -12px 3px;
    overflow: hidden;
    position: relative;
    top: -1px;
    line-height: 0px;
}
.osx-btn-split:before {
    display: block;
    content: '';
    background: rgba(0,0,0,0.4);
    position: relative;
    top: 0;
    left: 4.5%;
    margin-bottom: -28px;
    height: 26px;
    width: 1px;
    border-bottom: 1px solid #6F6F6F;
    box-shadow: inset 0 1px 0 #F6F6F6, 0 1px 0 #CDCDCD;
}
.osx-btn-split:active:before {
    background: #676767;
}
.osx-btn-split > .osx-btn:first-child {
    margin-right: -5px;
    border-radius: 3px 0 0 3px;
   ...