Css Fisheye Menu issues

I've some issue with coding a CSS Fisheye Menu.

This is my code :

/* dock */
.dock {
position: relative; 
height: 40px; 
text-align: center;
}


.dock-container {
    width: 500px;
height: 40px;
margin-left: auto;
margin-right: auto;
margin-top:40px;
margin-bottom: 100px;
bottom: 100px;
padding: 0px;

}
a.dock-item {
display:initial;
width: 20px;
color: #ffffff;
position: absolute;
margin-right: auto;
margin-left: auto;
padding: 2px;
border: none;
text-align: center;
text-decoration: none;
font: 500 14px Arial, Helvetica, sans-serif;
}


a:visited.dock-item{color:#555; text-decoration:none;}
.dock-item img {
border: none;
margin: 5px 10px 0px;
width: 100%; 
}
.dock-item span {
display: none; 
padding-left: 0px;
}

I want not to have padding between each item. In fact, I want the main item ( the center one ) to be bigger, and the other to be bellow and less opacity.