IE display issues

I have two problems with my pages rendering in IE, and I can’t seem to figure them out:

They concern this page:
https://theimaginaryboy.com/

1. (The easy one?) In IE, the content area/page heading is way closer to the website title than in Firefox. Does anyone know a hack to make the page render the same in each browser?

2. You might have noticed that IE does not display my menu, but Firefox does. I have no idea why this is happening. Ideas?

Here is the contents of my 2c-l.css:

/*
LAYOUT: Two-Column (Left)
DESCRIPTION: Two-column fluid layout with one sidebars left of content
*/
div#container {
float:right;
margin:0 0 0 -200px;
width:100%;
height:100%;
}

div#content {
margin:75px 0px 0px 215px;
width: 465px;
}

div.sidebar {
position:absolute;
top:100px;
left:55px;
overflow:hidden;
width:180px;
}

div#secondary {
clear:left;
}

div#footer {
clear:both;
width:100%;
}

Here is the contents of my style.css:

/*
THEME NAME: Sandbox
THEME URI: https://www.plaintxt.org/themes/sandbox/
DESCRIPTION: Rich with powerful and dynamic semantic class selectors, Sandbox is a canvas for CSS artists
VERSION: 1.6.1
AUTHOR: <a href="https://andy.wordpress.com/">Andy Skelton</a> & <a href="https://www.plaintxt.org/">Scott Allan Wallick</a>
AUTHOR URI:
TAGS: white, microformats, fixed-width, flexible-width, one-column, two-columns, three-columns, four-columns, left-sidebar, right-sidebar
*/

/* Two-column with sidebar on left from the /examples/ folder  */
@import url('examples/2c-l.css');

/* Just some example content */

body
{
background-image:url(/good-version.jpg);
margin:0;
padding:0;
}

div.skip-link {
position:absolute;
right:1em;
top:1em;
}

div#teststyle {
list-style-type:none;
}

A:link {
text-decoration: none;
color: #7F7400;
	}
A:visited {
text-decoration: none;
color: #7F7400;
}
A:active {
text-decoration: none;
color: #348A00;
	}
A:hover {
text-decoration: none;
color: #348A00;

	}

div#menu ul,div#menu ul ul {
line-height:1;
list-style:none;
margin:0;
padding:0;
}

div#menu ul a {
display:block;
margin-right:1em;
padding:0.2em 0.5em;
text-decoration:none;
}

div#menu ul ul ul a {
font-style:italic;
}

div#menu ul li ul {
left:-999em;
position:absolute;
}

div#menu ul li:hover ul {
left:auto;
}

.entry-title,.entry-meta {
clear:both;
}

div#container,div#primary {
margin-top:2em;
}

form#commentform .form-label {
margin:1em 0 0;
}

form#commentform span.required {
background:#fff;
color:#c30;
}

form#commentform,form#commentform p {
padding:0;
}

input#author,input#email,input#url,textarea#comment {
padding:0.2em;
}

div.comments ol li {
margin:0 0 3.5em;
}

textarea#comment {
height:13em;
margin:0 0 0.5em;
overflow:auto;
width:66%;
}

.alignright,img.alignright{
float:right;
margin:1em 0 0 1em;
}

.alignleft,img.alignleft{
float:left;
margin:1em 1em 0 0;
}

.aligncenter,img.aligncenter{
display:block;
margin:1em auto;
text-align:center;
}

div.gallery {
clear:both;
height:180px;
margin:1em 0;
width:100%;
}

p.wp-caption-text{
font-style:italic;
}

div.gallery dl{
margin:1em auto;
overflow:hidden;
text-align:center;
}

div.gallery dl.gallery-columns-1 {
width:100%;
}

div.gallery dl.gallery-columns-2 {
width:49%;
}

div.gallery dl.gallery-columns-3 {
width:33%;
}

div.gallery dl.gallery-columns-4 {
width:24%;
}

div.gallery dl.gallery-columns-5 {
width:19%;
}

div#nav-above {
margin-bottom:1em;
}

div#nav-below {
margin-top:1em;
}

div#nav-images {
height:150px;
margin:1em 0;
}

div.navigation {
height:1.25em;
}

div.navigation div.nav-next {
float:right;
text-align:right;
}

div.sidebar h3 {
font-size:1.2em;
}

div.sidebar input#s {
width:7em;
}

div.sidebar li {
list-style:none;
margin:0 0 2em;
line-height:25px;
}

div.sidebar li form {
margin:0.2em 0 0;
padding:0;
}

div.sidebar ul ul {
margin:0 0 0 1em;
}

div.sidebar ul ul li {
list-style:none;
margin:0;
}

div.sidebar ul ul ul {
margin:0 0 0 0.5em;
}

div.sidebar ul ul ul li {
list-style:circle;
}

div#menu ul li,div.gallery dl,div.navigation div.nav-previous {
float:left;
}

div#header,div#footer {
text-align:left;
}

input#author,input#email,input#url,div.navigation div {
width:50%;
}

div.gallery *,div.sidebar div,div.sidebar h3,div.sidebar ul {
margin:0;
padding:0;
}

Many thanks in advance.