.main_text{
text-align:left;
width: 670px;
margin-left: auto;
margin-right: auto;
}
.code {
border: 1px #d3d3d3 solid;
font-family: courier;
padding:5px;
font-size: 0.8em;
width:500px;
text-align: left;
margin-left: auto;
margin-right: auto;
}
.demo{
border-collapse:collapse;
padding: 0px;
margin-top: 30px; 
margin-left: auto;
margin-right: auto;
font-weight: bold;
}
.demo td {
padding: 5px;
text-align: center;
border: 1px #d3d3d3 solid; 
}
.button {
font-weight:normal;
font-size: 20px;
background-color: #000;
color: #000;
border:#b0b0b0 solid 1px;
border-radius: 3px;
padding:4px;
}
.client_txt{ margin:0; padding:10px 0; font-family:Verdana, Arial, Helvetica, sans-serif; font-size:13px; font-weight:normal; line-height:18px;}