Make Cyanus theme fluid width

Hi, With a little help from you guys I thought I had this figured out -but afraid not. I am trying to make my theme wider in the main content area so that it is not so scrunched up in the middle of the screen. I want to redo my entire gallery, but it really needs more width. How do I change the fixed width to fluid?

I have tried several times to change the px to % and all worked fine except for the main content section – I see no change in it. It just stays in the same spot. I have attached my stylesheet if someone would be so kind to tell me exactly which parts (header, sidebar, content, etc.) need to be modified. Some of the terms I have seen used by others here are not seen in my theme stylesheet, i.e. sidebar. Or perhaps I should be editing something other than the stylesheet??

Sorry I don’t know the correct terminology, but hopefully you know what I am trying to ask.

Thanks!

/*
Theme Name: Cyanus Theme
Theme URI: http://luckythemes.com/cyanus-theme/
Description: Art style blue color wordpress theme
Version: 1.4
Author: http://themerama.com
Tags: widget ready, valid html, valid css, 2 columns, fixed width, art, blue
*/

body
{
font-family:Arial, Helvetica, sans-serif;
font-size:12px;
color:#FFF;
background:#052038 url(images/bg.jpg);
text-align:center;
margin:0;
padding:0;
}

.clear
{
clear:both;
}

#header
{
width:857px;
height:241px;
background:#1E1C41 url(images/header_bg.jpg) no-repeat;
text-align:left;
margin:7px auto 0;
}

#header .title1
{
width:240px;
height:145px;
float:left;
margin-left:47px;
padding-top:50px;
}

#header .title2
{
width:480px;
height:30px;
float:right;
margin-right:20px;
padding-top:180px;
text-align:right;
}

#header h1
{
font-weight:400;
font-size:24px;
text-align:center;
margin:0;
padding:0;
}

#header h4
{
font-weight:400;
font-size:16px;
color:#FFF;
font-style:italic;
margin:0;
padding:0;
}

#header a:link,#header a:visited,#header a:active,#header a:hover
{
color:#0060FF;
text-decoration:none;
}

#header a:hover
{
color:#FFF;
}

.search_form
{
margin:0 0 5px;
padding:0;
}

.search_form input
{
vertical-align:middle;
margin:0 10px;
padding:0;
}

.search_form input.text
{
width:80px;
}

#content
{
width:857px;
text-align:left;
margin:0 auto;
}

#content .padding
{
margin-left:12px;
background:#06183C url(images/cont_bg.jpg) repeat-y;
}

.left
{
float:left;
width:197px;
}

.left .lpadding
{
margin:0;
}

.left .title
{
background:url(images/cat_bg.jpg) no-repeat;
padding:13px 5px 13px 30px;
}

.left h1
{
font-size:14px;
text-transform:uppercase;
color:#FFF;
font-weight:400;
margin:0;
padding:0;
}

.left ul li
{
list-style:disc;
font-size:14px;
margin:0 10px 0 20px;
padding:2px 5px 2px 0;
}

.left ul
{
margin:10px;
padding:0;
}

.left a:link,.left a:visited,.left a:active,.left a:hover
{
color:#5C708B;
text-decoration:none;
}

.right
{
float:right;
width:645px;
}

.right .rpadding
{
margin:2px;
}

.right .title
{
border-bottom:1px dashed #FFF;
padding:5px;
}

.right h1
{
font-weight:400;
font-size:18px;
text-transform:uppercase;
margin:0;
padding:0;
}

.right h1 a:link,.right h1 a:visited,.right h1 a:active,.right h1 a:hover
{
color:#FFF;
text-decoration:none;
}

.right h4
{
font-weight:400;
font-size:12px;
color:#FFF;
margin:0;
padding:0;
}

.right .post_top
{
background:url(images/01_06.jpg) no-repeat center;
height:8px;
}

.right .post
{
background:#10172E;
border:5px solid #1E2748;
margin:0 10px;
padding:5px 10px;
}

.right .post_bttm
{
background:url(images/01_14.jpg) no-repeat center;
height:13px;
margin-bottom:20px;
}

.right .title h1
{
width:420px;
float:left;
}

.right .title h4
{
width:80px;
float:right;
text-align:right;
padding-top:5px;
}

.right p
{
margin:5px;
}

.right a:link,.right a:visited,.right a:active,.right a:hover
{
color:#5C708B;
text-decoration:underline;
}

.tags,.permalink
{
text-align:left;
color:#E8D3DF;
font-size:11px;
border-left:1px dashed #FFF;
border-right:1px dashed #FFF;
background:#020715;
margin:0 0 1px;
padding:3px 5px;
}

.permalink
{
color:#E8D3DF;
text-align:right;
margin:0 0 5px;
}

#footer
{
font-family:Tahoma, Arial, Helvetica, Georgia, Verdana, sans-serif;
font-weight:400;
text-align:center;
color:#FEFAFC;
width:857px;
font-size:11px;
margin:0 auto;
}

#footer .padding
{
margin-left:12px;
background:#1E1C41 url(images/footer_bg.jpg) no-repeat;
height:67px;
}

#footer p
{
margin:0;
padding:20px 0 0;
}

#footer a:link,#footer a:visited,#footer a:active,#footer a:hover
{
font-weight:700;
color:#FEFAFC;
text-decoration:underline;
}

#footer a.sec:link,#footer a.sec:visited,#footer a.sec:active,#footer a.sec:hover
{
color:#FEFAFC;
font-weight:700;
text-decoration:underline;
}

h2
{
font-weight:400;
font-size:18px;
}

h3
{
font-weight:400;
font-size:16px;
}

#commentform #author,#commentform #email,#commentform #url,#commentform textarea
{
background:#fff;
border:1px solid #333;
padding:.2em;
}

#commentform textarea
{
width:99%;
}

#commentlist li ul
{
border-left:1px solid #ddd;
font-size:110%;
list-style-type:none;
}

#commentlist li .avatar
{
float:right;
margin-right:25px;
border:1px dotted #ccc;
padding:2px;
}

#wp-calendar
{
border:1px dotted #1E2748;
empty-cells:show;
font-size:14px;
width:90%;
margin:0 auto 10px;
}

#wp-calendar #next a
{
padding-right:10px;
text-align:right;
}

#wp-calendar #prev a
{
padding-left:10px;
text-align:left;
}

#wp-calendar a
{
display:block;
text-decoration:none;
}

#wp-calendar a:hover
{
background:#e0e6e0;
color:#333;
}

#wp-calendar caption
{
color:#FFF;
font-size:14px;
text-align:center;
}

#wp-calendar td
{
color:#FFF;
font:normal 12px ‘Lucida Grande’, ‘Lucida Sans Unicode’, Verdana, sans-serif;
letter-spacing:normal;
text-align:center;
padding:2px 0;
}

#wp-calendar td.pad:hover
{
background:#fff;
}

#wp-calendar td:hover,#wp-calendar #today
{
background:#eee;
color:#000;
}

#wp-calendar th
{
font-style:normal;
text-transform:capitalize;
}

p img
{
max-width:100%;
padding:0;
}

img.alignright
{
display:inline;
margin:0 0 2px 7px;
padding:4px;
}

img.alignleft
{
display:inline;
margin:0 7px 2px 0;
padding:4px;
}

.alignright
{
float:right;
}

.alignleft
{
float:left;
}

img,.left ul li ul li,.left ul li ul li ul li
{
border:0;
}

.left a:hover,.right h1 a:hover
{
text-decoration:underline;
}

.right a:hover,.tags a:hover,.permalink a:hover,#footer a:hover,#footer a.sec:hover
{
text-decoration:none;
}

.tags a:link,.tags a:visited,.tags a:active,.tags a:hover,.permalink a:link,.permalink a:visited,.permalink a:active,.permalink a:hover
{
color:#E8D3DF;
text-decoration:underline;
}

img.centered,.aligncenter
{
display:block;
margin-left:auto;
margin-right:auto;
}

.right ul li,.right ol li
{
margin:0 10px;
}