Greetings,
I've tried to google how you have your logo auto center across your header on the forum. There's a lot of people that have various ways. I do my own and many will have various ways to go about it. Here is the simple version.
Open your "Header" template.
Look for the last </script> tag in your code and insert after it:
Code:
<style>
#logo {
display: block;
margin-left: auto;
margin-right: auto
}
</style>
Next you will need to look for this section of code which contains your header info
Code:
<div><a name="top" href="{vb:raw vboptions.forumhome}.php{vb:raw session.sessionurl_q}" class="logo-image"><img src="{vb:stylevar titleimage}"
alt="{vb:rawphrase x_powered_by_vbulletin, {vb:raw vboptions.bbtitle}}" /></a></div>
I modified that a little bit to have the following. There are a few things that you can keep or get rid of if you wish. I chose to eliminate some things I really dont need as I customize my forum a lot.
Code:
<a href="{vb:raw vboptions.forumhome}.php{vb:raw session.sessionurl_q}"><img id="logo" src="{vb:stylevar titleimage}"/></a>
You should now have a centered Logo Image on your forum header that scales centered as your screen size changes.