Look at /includes/templates/classic/css/stylesheet.css and compare it with /includes/templates/template_default/css/stylesheet.css. If they are the same, that is your problem. Get a fresh copy of /includes/templates/classic/css/stylesheet.css from a downloaded set of Zen Cart files. The same fix applies if your copy of /includes/templates/classic/css/stylesheet.css is missing.
A side note - it looks like you have been using an HTML editor to make up text. They can generate horrendous code if not managed properly. Your tagline shows this:
HTML Code:
<div id="taglineWrapper">
<div id="tagline"><FONT color=#009300 size=7><STRONG><FONT face="Times New Roman">
<P align=center><FONT size=1><FONT color=#3cb371 size=3><FONT size=7>Arkwright & Gladys <FONT size=3><FONT size=1><FONT color=#3cb371 size=3><FONT size=3>Pet</FONT></FONT></FONT><FONT size=1><FONT color=#3cb371><FONT size=3> Supplies - Fishing Tackle & Baits - Floral Sundries - DIY Products</FONT></FONT></FONT></FONT></FONT></FONT></FONT><FONT size=1><FONT color=#3cb371></P></FONT></FONT><FONT size=3></FONT></FONT></STRONG></FONT></div>
</div>
when what you actually need inside the <div id="tagline"> is two <font> tags and possibly a <strong> and <p>. There is a lot of garbage in there now.