CSS - Styling a button

Sample CSS:

#btn a {
color: #000000;
font-size:10px;
font-family:verdana;
font-weight:bold;
text-decoration: none;
border:4px outset #cc9900;
background-color:#00ffff;
display: block;
width: 160px;
padding: 3px 5px;
margin: 1px;
}
#btn a:hover {
background-color: #00c0c0;
color:#000000;
padding-left:4px;
border:4px inset aqua;
}