Simplenews style for body

Thanks to the Simplenews Template module I can adjust/ define the header and the footer. But I am facing difficulties with the body of the newsletter. I've set the width op both the header and the footer to a 575 px; but can't get it working for the body. Therefor the text in the body doesn't align on the righthand side with both the header and footer of 575 px. Any idea's? Below the mail.css I've used;

.body
{
position: absolute;
font-family: Arial, Helvetica, Sans-Serif;
color: #000000;
margin: 0 auto;
margin-bottom: 0px;
margin-left: 0px;
margin-right: 0px;
margin-top: 0px;
padding: 0;
vertical-align: top;
background-color: #ffffff;
}

.simplenews-template-body {
position: absolute;
width: 575px;
margin-left: 0px;
margin-right: -575px;
overflow:hidden;
background-color: #ffffff;
font-family: Arial, Helvetica, Sans-Serif;
color: #000000;
font-size: 12px;
}

h1 {
font-family: Arial, Helvetica, Sans-Serif;
font-size: 18px;
font-style: normal;
font-weight: bold;
text-align: left;
color: #000000;
}

h2, h2 a, h2 a:link, h2 a:visited, h2 a:hover {
font-family: Arial, Helvetica, Sans-Serif;
font-size: 18px;
font-style: normal;
font-weight: bold;
text-align: left;
color: #000000;
}

.simplenews-template-header
{
background-color: #ffffff;
font-family: Arial, Helvetica, Sans-Serif;
color: #000000;
font-size: 12px;
}

.simplenews-template-footer {
position: absolute;
width: 575px;
left: 0;
padding: 15px;
overflow:hidden;
background-color: #e72404;
font-family: Arial, Helvetica, Sans-Serif;
color: #ffffff;
font-size: 11px;
}

.simplenews-template-footer a:link, a:visited, a:active, a:hover {
font-family: Arial, Helvetica, Sans-Serif;
color: #ffffff;
font-size: 11px;
}

.newsletter-footer {
background-color: #ffffff;
font-family: Arial, Helvetica, Sans-Serif;
color: #000000;
font-size: 12px;
}

.newsletter-footer a:link, a:visited, a:active, a:hover {
background-color: #ffffff;
font-family: Arial, Helvetica, Sans-Serif;
color: #000000;
font-size: 12px;
}