How do I do this? (bottom colors)

Hello guys! I´m putting up a blog for my business (http://blog.videographia.com.br/) and its bottom is completely white, but I want to have my blog like these ones for example (http://www.calvinayrelife.com/ and http://www.blog.lifestagevideography.com/), or in other words, with the bottom in black but with a rectangle in the middle in white where the body text should be placed. Does anyone know how to do that? Is it very difficult? I´m attaching below the Stylesheet of my blog, so if anyone can show me what I have to do, I´d appreciate it a lot! Sorry for my English, it is not perfect yet. Thanks a lot!

/*
Theme Name: Cutline
Theme URI: http://pearsonified.com
Description: A squeaky clean, feature-rich theme for WordPress designed and coded by Chris Pearson.
Version: 1.2
Author: Chris Pearson
Author URI: http://pearsonified.com/
*/

body { background: #fff; color: #333; font: 62.5% Georgia, “Times New Roman”, Times, serif; text-align: center; }

* { padding: 0; margin: 0; }

/*—:[ global elements ]:—*/

a { color: #0060ff; text-decoration: underline; }

a:visited { color: #333; text-decoration: underline; }

a:hover { color: #df0000; text-decoration: underline; }

a img { border: none; }

blockquote { font-style: italic; font-family: Georgia, “Times New Roman”, Times, serif; color: #555; margin: 0 30px 1.5em 30px; padding: 0 0 0 10px; border-left: 1px solid #aaa; }

abbr, acronym { border-bottom: 1px dotted #aaa; text-transform: uppercase; cursor: help; }

code { color: #090; font-family: Courier, monospace; }

pre { margin: 0 0 1.5em 0; overflow: auto; font-size: 1.3em; clear: both; }

p.center { text-align: center !important; }

p.bottom { margin: 0 !important; }

p.unstyled { font-size: 1.4em; }

.flickr_blue { color: #007ae4; text-transform: lowercase; }

.flickr_pink { color: #ff2a96; text-transform: lowercase; }

.green { color: #090; }

.red { color: #f00; }

.orange { color: #f40; }

.purple { color: #909; }

/*—:[ headlines ]:—*/

h1, h2, h3 { font-weight: bold; font-family: Helvetica, Arial, sans-serif; color: #000; }

h1 { font-size: 3.6em; letter-spacing: -0.03em; }

#masthead h1 { padding: 0.4em 0 0.2em 0; border-top: 1px solid #ccc; text-align: center; clear: both; }

h1 a, h1 a:visited, h1 a:hover { color: #000; text-decoration: none; }

h2 { font-size: 2.0em; }

h2 a { color: #000; text-decoration: none; }

h2 a:visited { color: #555; text-decoration: none; }

h2 a:hover { color: #090; text-decoration: none; }

.posts h2 { margin: 0 0 0.1em 0; line-height: 1.2em; }

.pages h2, h2.page_header { margin: 0 0 0.75em 0; padding: 0 0 0.6em 0; background: url(‘images/hr_title_sep.gif’) 0 100% no-repeat; }

h2.archive_head { font-weight: bold !important; font-size: 1.4em !important; text-transform: uppercase !important; letter-spacing: normal !important; margin: 0 0 1.8em 0 !important; padding: 0.4em 2px !important; border-top: 3px solid #000 !important; background: url(‘images/hr_dot_black.gif’) 0 100% repeat-x !important; }

h3 { font-size: 1.0em; text-transform: uppercase; }

#masthead h3 { margin: 0 0 0.75em 0; font-weight: normal; font-size: 1.8em; text-transform: none; color: #888; text-align: center; }

.entry h3 { margin: 2.5em 0 0.5em 0; }

.entry h3.top { margin: 1.5em 0 0.5em 0 !important; }

h3.comments_headers { font-size: 1.4em; }

h4 { font: italic 1.2em Georgia, “Times New Roman”, Times, serif; color: #888; }

h4 a, h4 a:visited { color: #888; text-decoration: none; }

h4 a:hover { color: #888; text-decoration: underline; }

.posts h4 { margin: 0 0 1.25em 0; padding: 0 0 1.0em 0; background: url(‘images/hr_title_sep.gif’) 0 100% no-repeat; }

/*—:[ core layout elements ]:—*/

#container { width: 770px; margin: 15px auto 0 auto; }

#content_box { width: 770px; text-align: left; float: left; clear: both; }

#content { width: 500px; padding: 0 40px 0 0; float: left; }

#sidebar { width: 230px; float: left; }

#footer { width: 770px; padding: 1.2em 0 0 0; border-top: 2px solid #ccc; float: left; clear: both; }

/*—:[ header styles ]:—*/

#masthead { width: 770px; /*height: 100px; background: url(‘images/logo.gif’) no-repeat;*/ /* uncomment the height and background declarations here if you intend to use a graphic in the header instead of the h1 */ }

/* #masthead a { display: block; width: 770px; height: 100px; } */ /* uncomment this line if you use a graphic in the header – make sure the height of your header graphic is equal to the height declared in this line of code! */

ul#nav { list-style: none; width: 750px; padding: 0 10px; background: url(‘images/hr_dot_black.gif’) repeat-x; border-bottom: 3px solid #000; float: left; clear: both; }

ul#nav li { padding: 0.85em 40px 0.7em 0; font: bold 1.4em Helvetica, Arial, sans-serif; text-transform: uppercase; float: left; }

ul#nav li a, ul#nav li a:visited { color: #000; text-decoration: none; }

ul#nav li a:hover { color: #000; text-decoration: underline; }

ul#nav li a.current, ul#nav li a.current:visited, ul#nav li a.current:hover { color: #090; text-decoration: underline; }

ul#nav li.rss { padding: 0.85em 0 0.7em 0; float: right; }

ul#nav li.rss a { padding: 0 18px 0 0; background: url(‘images/icon_rss.gif’) 100% 50% no-repeat; }

#header_img { position: relative; margin: 0 0 3.0em 0; border-bottom: 1px solid #000; float: left; clear: both; }

#header_img img { display: block; } /* this is really just an IE 6 and 7 hack in disguise */

/*—:[ content styles ]:—*/

.entry { font-size: 1.4em; line-height: 1.65em; }

.entry blockquote { font-size: 1.0em; }

.entry blockquote.right { width: 200px; font-style: normal !important; font-size: 1.3em !important; margin: 0.3em 0 0.3em 15px !important; padding: 0.3em 0 !important; border: 3px double #aaa; border-width: 3px 0; text-align: center; float: right; }

.entry blockquote.left { width: 200px; font-style: normal !important; font-size: 1.3em !important; margin: 0.3em 15px 0.3em 0 !important; padding: 0.3em 0 !important; border: 3px double #aaa; border-width: 3px 0; text-align: center; float: left; }

.entry blockquote.right p, .entry blockquote.left p { margin: 0 !important; line-height: 1.4em !important; }

.entry p { margin: 0 0 1.5em 0; }

.entry ul, .entry ol { margin: 0 0 1.5em 40px; }

.entry ul { list-style-type: square; }

.entry li { margin: 0 0 0.5em 0; }

.entry ul li ul, .entry ul li ol, .entry ol li ul, .entry ol li ol { margin: 0.5em 0 0.5em 30px; }

.entry dl { margin: 0 0 1.5em 0; }

.entry dt { font-weight: bold; margin: 0 0 0.5em 0; }

.entry dd { margin: 0 0 1.5em 20px; }

.entry .ad { margin: 0 0 0.5em 15px; float: right; }

.entry .ad_left { margin: 0 15px 0.5em 0; float: left; }

.entry img { max-width: 490px; }

.entry img.left { padding: 3px; margin: 0.5em 15px 0.5em 0; border: 3px double #bbb; float: left; clear: left; }

.entry img.right { padding: 3px; margin: 0.5em 0 0.5em 15px; border: 3px double #bbb; float: right; clear: right; }

.entry img.center { display: block; padding: 3px; margin: 0 auto 1.5em auto; border: 3px double #bbb; float: none; clear: both; }

.entry img.off { padding: 0 !important; border: none !important; }

.entry img.stack { clear: none !important; }

.tagged { padding: 0.4em 0 0 0; background: url(‘images/hr_tag_sep.gif’) no-repeat; font-size: 1.2em; line-height: 1.6em; color: #888; clear: both; }

.tagged a, .tagged a:visited { padding: 0.25em; color: #333; text-decoration: none; }

.tagged a:hover { color: #fff; background: #333; text-decoration: none; }

.add_comment { display: block; padding: 0 0 0 20px; font-weight: bold; float: right; }

.navigation { width: 500px; font-size: 1.4em; float: left; }

.previous { padding: 0 20px 0 0; float: left; }

.next { float: right; }

.clear { width: 500px; height: 1px; margin: 0 0 5.0em 0; clear: both; }

.rule { background: url(‘images/hr_tag_sep.gif’) no-repeat; }

.flat { margin: 0 0 2.0em 0 !important; }

.whitespace { margin: 0 0 3.5em 0 !important; }

/*—:[ sidebar styles ]:—*/

ul.sidebar_list { list-style: none; }

ul.sidebar_list li.widget, ul.sidebar_list li.linkcat { width: 230px; margin: 0 0 2.5em 0; font-size: 1.3em; line-height: 1.4em; float: left; }

li.widget h2, li.linkcat h2 { font-weight: bold; font-size: 1.077em; text-transform: uppercase; letter-spacing: normal; margin: 0 0 0.8em 0; padding: 0.4em 2px; border-top: 3px solid #000; background: url(‘images/hr_dot_black.gif’) 0 100% repeat-x; }

li.widget p { margin: 0 0 1.5em 0; padding: 0 10px; }

li.widget ul, li.linkcat ul { list-style: square; margin: 0 0 0.5em 20px; }

li.widget ol, li.linkcat ol { margin: 0 0 0.5em 20px; }

li.widget li, li.linkcat li { margin: 0 0 0.7em 0; }

li.widget li a, li.widget li a:visited, li.linkcat li a, li.linkcat li a:visited { text-decoration: none; }

li.widget li a:hover, li.linkcat li a:hover { text-decoration: underline; }

li.widget li .recent_date { padding: 0 0 0 8px; font-weight: bold; color: #888; }

li.widget ul.flickr_stream { list-style: none; margin: 0; padding: 0 10px; }

li.widget ul.flickr_stream li { margin: 0; padding: 0 5px 5px 0; display: inline; }

li.widget ul.flickr_stream li a img { padding: 3px; }

li.widget ul.flickr_stream li a:hover img { background: #ff2a96; }

/*—< FlickrRSS styles for the widget only >—*/

li.widget_flickrrss { }

li.widget_flickrrss a img { margin: 0 5px 5px 0; padding: 3px; }

li.widget_flickrrss a:hover img { background: #ff2a96; }

/*—< Calendar widget styles >—*/

#calendar_wrap { font-size: 1.3em; }

/*—:[ footer styles ]:—*/

#footer p { margin: 0 0 0.923em 0; font-size: 1.3em; color: #888; text-align: right; }

#footer a, #footer a:visited { color: #888; text-decoration: none; }

#footer a:hover { color: #888; text-decoration: underline; }

/*—:[ comment styles ]:—*/

#comments { width: 500px; float: left; clear: both; }

ul#comment_list { list-style: none; margin: 0 0 4.0em 0; border-top: 1px solid #bbb; float: left; }

ul#comment_list li.comment { width: 500px; padding: 1.2em 0 0 0; border-bottom: 1px dotted #bbb; float: left; }

ul#comment_list li.trackback { width: 470px; padding: 1.2em 15px 0 15px; background: url(‘images/trackback_bg.gif’); }

.comment_meta { margin: 0 0 1.2em 0; }

.comment_num { padding: 0 15px 0 20px; font-weight: bold; font-size: 1.4em; float: right; }

.trackback .comment_num { padding: 0 0 0 20px; }

.comment_num a, .comment_num a:visited { color: #888; text-decoration: none; }

.comment_num a:hover { color: #df0000; text-decoration: none; }

.comment_meta strong { font-size: 1.6em; }

.comment_time { font: normal 1.1em Verdana, Helvetica, Arial, sans-serif; color: #888; }

.comment .entry { padding: 0 15px; }

.comment .entry p { margin: 0 0 1.0em 0; }

/*—:[ comment form styles ]:—*/

#comment_form { width: 500px; padding: 1.0em 0 0 0; float: left; }

#comment_form p { padding: 0.6em 0; }

#comment_form label { padding: 0 0 0 10px; font-size: 1.2em; }

#comment_form .text_input { width: 191px; padding: 3px; color: #444; font: normal 1.4em Georgia, “Times New Roman”, Times, serif; border-top: 2px solid #999; border-left: 2px solid #999; border-right: 1px solid #fff; border-bottom: 1px solid #fff; }

#comment_form .text_area { width: 321px !important; }

#comment_form .text_input:focus { border-top: 2px solid #666; border-left: 2px solid #666; border-right: 1px solid #ddd; border-bottom: 1px solid #ddd; }

#comment_form .form_submit { padding: 0.4em 4px; background: url(‘images/submit_bg.gif’); border: 3px double #999; border-top-color: #ccc; border-left-color: #ccc; font: bold 1.4em Georgia, “Times New Roman”, Times, serif; cursor: pointer; }

#comment_form p.subscribe-to-comments { font-size: 1.4em; }

#comment_form p.subscribe-to-comments label { font-size: 1.0em; }

/*—:[ search form styles ]:—*/

#search_form { }

#search_form .search_input { width: 221px; padding: 3px; color: #090; font: normal 1.0em Georgia, “Times New Roman”, Times, serif; border-top: 1px solid #999; border-left: 1px solid #999; border-right: 1px solid #f5f5f5; border-bottom: 1px solid #f5f5f5; }

li.widget .search_input { font-size: 1.1em !important; }

#search_form .search_input:focus { border-top: 1px solid #666; border-left: 1px solid #666; border-right: 1px solid #ddd; border-bottom: 1px solid #ddd; }