Oh no, those are not in your CSS. They are probably in your template files (the ones with the PHP endings). Try index.php first.
As a first step, try removing these:
<div class="Sheet-tl"></div>
<div class="Sheet-tr"><div></div></div>
<div class="Sheet-bl"><div></div></div>
<div class="Sheet-br"><div></div></div>
<div class="Sheet-tc"><div></div></div>
<div class="Sheet-bc"><div></div></div>
<div class="Sheet-cl"><div></div></div>
<div class="Sheet-cr"><div></div></div>
<div class="Sheet-cc"></div>
Try adding this to your CSS file:
.post a,
.post a:visited {
text-decoration: none;
color: #336699;
}
.post a:hover {
text-decoration: underline;
}
