.a-btn {
background: #454545;
background-image: -webkit-linear-gradient(top, #c3c3c3, #343434);
background-image: -moz-linear-gradient(top, #454545, #343434);
background-image: -ms-linear-gradient(top, #454545, #343434);
background-image: -o-linear-gradient(top, #454545, #343434);
background-image: linear-gradient(top, #454545, #343434);
padding-left: 20px;
padding-right: 80px;
height: 38px;
width: 110px;
display: inline-block;
position: relative;
border: 1px solid #5d81ab;
box-shadow: 0px 1px 1px rgba(255, 255, 255, 0.8) inset, 1px 1px 3px rgba(0, 0, 0, 0.2), 0px 0px 0px 4px rgba(188, 188, 188, 0.5);
-moz-box-shadow: 0px 1px 1px rgba(255, 255, 255, 0.8) inset, 1px 1px 3px rgba(0, 0, 0, 0.2), 0px 0px 0px 4px rgba(188, 188, 188, 0.5);
-webkit-box-shadow: 0px 1px 1px rgba(255, 255, 255, 0.8) inset, 1px 1px 3px rgba(0, 0, 0, 0.2), 0px 0px 0px 4px rgba(188, 188, 188, 0.5);
border-radius: 20px;
-moz-border-radius: 20px;
-webkit-border-radius: 20px;
float: left;
clear: both;
margin: 10px 0px;
overflow: hidden;
text-decoration: none;
transition: all 0.3s linear;
}
.a-btn-text {
padding-top: 10px;
padding-left: 10px;
display: block;
font-size: 14px;
font-face:"Arial";
white-space: nowrap;
text-shadow: 0px 1px 1px #000000;
color: #96a0af;
font-variant: small-caps;
font-weight: bold;
}
.a-btn-slide-text {
position:absolute;
height: 100%;
top: 1px;
right: 52px;
width: 0px;
background: #63707e;
background-image: -webkit-linear-gradient(top, #52606d, #63707e);
background-image: -moz-linear-gradient(top, #52606d, #63707e);
background-image: -ms-linear-gradient(top, #52606d, #63707e);
background-image: -o-linear-gradient(top, #52606d, #63707e);
background-image: linear-gradient(top, #52606d, #63707e);
text-shadow: 0px 1px 1px #363f49;
color: #fff;
font-size: 9px;
white-space: nowrap;
text-transform: uppercase;
text-align: left;
text-indent: 10px;
overflow: hidden;
line-height: 38px;
box-shadow: -1px 0px 1px rgba(255, 255, 255, 0.4), 1px 1px 2px rgba(0, 0, 0, 0.2) inset;
-moz-box-shadow: -1px 0px 1px rgba(255, 255, 255, 0.4), 1px 1px 2px rgba(0, 0, 0, 0.2) inset;
-webkit-box-shadow: -1px 0px 1px rgba(255, 255, 255, 0.4), 1px 1px 2px rgba(0, 0, 0, 0.2) inset;
transition: width 0.3s linear;
font-variant: small-caps;
font-weight: bold;
}
.a-btn-icon-right {
position: absolute;
right: 0px;
top: 0px;
height: 100%;
width: 52px;
border-left: 1px solid #5d81ab;
box-shadow: 1px 0px 1px rgba(255, 255, 255, 0.4) inset;
-moz-box-shadow: 1px 0px 1px rgba(255, 255, 255, 0.4) inset;
-webkit-box-shadow: 1px 0px 1px rgba(255, 255, 255, 0.4) inset;
}
.a-btn-icon-right span {
width: 38px;
height: 38px;
position: absolute;
left: 50%;
top: 50%;
margin: -20px 0px 0px -20px;
background: transparent;
transition: all 0.3s linear;
}
.a-btn:hover {
padding-right: 180px;
box-shadow: 0px 1px 1px rgba(255, 255, 255, 0.8) inset, 1px 1px 3px rgba(0, 0, 0, 0.2), 0px 0px 0px 4px rgba(188, 188, 188, 0.5);
-moz-box-shadow: 0px 1px 1px rgba(255, 255, 255, 0.8) inset, 1px 1px 3px rgba(0, 0, 0, 0.2), 0px 0px 0px 4px rgba(188, 188, 188, 0.5);
-webkit-box-shadow: 0px 1px 1px rgba(255, 255, 255, 0.8) inset, 1px 1px 3px rgba(0, 0, 0, 0.2), 0px 0px 0px 4px rgba(188, 188, 188, 0.5);
text-shadow: 0px 1px 1px #000000;
}
.a-btn:hover .a-btn-text {
color: #b5b5b5;
}
.a-btn:hover .a-btn-slide-text {
width: 125px;
}

<a href="$ADD_ENTRY_LINK$" class="a-btn">
<span class="a-btn-text">ДОБАВИТЬ</span>
<span class="a-btn-slide-text">новый материал</span>
<span class="a-btn-icon-right"><span></span></span>
</a>
<div style="padding: 5px; clear: both;"></div>