Help me on my Css and Archive.php

How to center the post title in my CSS?

Here is my post css:

h2.post-title a:link,
h2.post-title a:visited {
color:#0066cc;
}

h2.post-title a:hover {
color:#0066cc;
border-bottom: 1px dashed #a0a0a0;
}

.post-content {
color:#444;
margin:15px 0 0 0;
width:500px;
overflow:hidden;
padding:0 !important;
padding:0 0 15px 0;
}

.post-content a:link,
.post-content a:visited {
color:#0066cc
}

.post-content a:hover {
color:#0066cc;
border-bottom: 1px dashed #a0a0a0;
}

.post-content img,
.post-content img:hover {
padding:0;
border:0;
}

.post-content ul li {
background: url(‘images/bullet.gif’) no-repeat 0 0;
list-style:none;
padding:0 0 0 15px;
margin:6px 0 0 -10px;
}

.post-content ol li {
padding:0;
margin:6px 0 0 0px;
}

.postmeta {
margin: 8px 2px;
font-size:8pt;
}

.post-date {
background: url(images/date.gif) no-repeat 0 0;
padding: 0 0 0 20px;
}

.post-comment {
background: url(images/commentslink.png) no-repeat 0 0;
padding: 0 0 0 20px;
}

.post-comment a:link,
.post-comment a:visited,
.post-comment a:hover {
color:#008000
}

.post-filed {
background: url(images/filed.gif) no-repeat 2px 0;
padding: 0 0 0 20px;
}

.more-link{
margin:0
}