Name of Blog incorrectly showing over Header image

My blog at https://www.marketingdefined.com/blog recently broke.

It is now restored and temporarily housed in the theme “Shaded Grey” until I reconfigure Semiologic to my specs.

Have unsuccessfuly been trying to drop a header graphic 800×80 into Shaded Grey to replace the theme’s header of the same dimensions, but the Blog “name” of “Marketing Defined” is erroneously showing/overwriting the header.. in #fff or the color white… and just the one line of white lettering (Marketing Defined) only forms the hyperlink to the home page of https://www.marketingdefined.com/blog.

Whereas, instead I would like the entire header graphic to be hyperlinked to the home page and that ugly one line of ghostly white lettering of “Marketing Defined” to disappear altogther.

My first question is how do I get rid of that ugly white lettering appearing over the header graphic without losing the ability to have the entire header graphic hyperlinked to the home page.

The entire CSS for the header template is a rather brief:

<div id="header">
<h1><a href="<?php bloginfo('url'); ?>"
title="<?php bloginfo('name'); ?>">
<?php bloginfo('name'); ?></a></h1></div>

and the “header” section of the theme’s Stylesheet is:

#header {
margin: 0;
padding: 20px 0 7px 1em;
border-bottom: 1px solid #ebebeb;
background: #fff url(‘img/header.jpg’) no-repeat center;
height:60px;}

(that is the entire CSS code for the “header” in the Shaded Grey theme – it does not give any design rules for the “header image” or “headerimg” as I have noticd in other WP themes)

Have tried taking out various parts of the php in the header template, but if I succeed in taking out the white overwrite, then the header is no longer hyperlinked to the home page. HELP, please.

My second question: what does this one line of CSS about the”html” for the body of the sidebar mean? Does it mean that a URL in the sidebar can take up the entire 180px dimension of the sidebar before it wraps?

html>body #sidebar {
width: 180px;
}

Two pretty basic questions – but they have me stumped. Any help is greatly appreciated.

Roseanne