Is there a way to make the entire header image a link to the main page?

I’m using the Nebula-10 theme and I have placed my logo in the head.gif file, instead of using the blog title text.

The website is https://www.crossfitclackamas.com

I can’t for the life of me figure out how to make the head.gif file a link back to the main page.

Here’s the head section from style.css:

#head {	background:url(images/head.gif) no-repeat top center; margin:auto; width:893px; height:72px; padding-top:9px; padding-right: 16px; text-align:center; }	

	.blogtitle, .blogtitle a{ font-size:35px; color: #84C1FF; }

	.blogtitle a:hover {text-decoration:none}

	.blogdesc {	font-size:15px;	color: #84C1FF; }

And the call from index.php:

<div id="head"><span class="blogtitle"><a href="<?php bloginfo('url'); ?>/" ><?php bloginfo('name'); ?></a></span>

I am not using the blogtitle and bloginfo fields since my logo is part of head.gif.

I’m not well read on php and css, though maybe it’s time to learn.

Any thoughts?