Hi,
I am very new to websdesign and for the first time I am strying to build my website. I am trying to hide the sidebar on the left on the homepage and the about page. How can I do that? I appreciate if someone can help me. Here is the eb and the css:
http://www.memastudio.ca/
/*
Theme Name: Mahsa
Version: 1.0
Theme URI:
Description: Custom for memastudio.ca Twentytwelve child theme.
Author: memastudio.ca
Author URI: http://memastudio.ca
Template: twentytwelve
*/

/* Import layout */
@import url(../twentytwelve/style.css);


/*--visually hide site title but keep SEO --*/
.site-title { position: absolute !important; clip: rect(1px 1px 1px 1px); /* IE7 */ clip: rect(1px, 1px, 1px, 1px); }

/*
At 1060px ( but could be 1200px )

content
320/1060*100=30.1886792453

slideshow
500/1060*100=47.1698113208

padding left and right for slideshow
30/1060*100=2.83018867925

sidebar
180/1060*100=16.9811320755
*/

.site-header { margin-bottom: 0; padding: 12px 0;
}
.site-logo { text-align: center; }
.entry-content img, .comment-content img,
.widget img, img.header-image,
.author-avatar img, img.wp-post-image { border-radius: 0; box-shadow: none; }

.site-content article { border: 0; }

#respond form p.form-allowed-tags { display: none; }
footer[role="contentinfo"] { text-align: right; }

.entry-content p {
font-size: 88%;
}


article, aside, details, figcaption, figure, footer, header, hgroup, nav, section {
margin-top: 10px;
}

.showbox .slideshow-wrapper .pager img { width: 60px; }
.slideshow-nav { font-size: 90%; }

/* Minimum width of 600 pixels. */
@media screen and (min-width: 600px) {
.site { max-width: 1060px; }
.site-logo { text-align: left; }
.page-template-project-showcase-php .site-content { width: 30.1886792453%; }
.page-template-project-showcase-php .widget-area { width: 16.9811320755%; }
.page-template-project-showcase-php .showbox { float: left; width: 50%; margin: 0px; }
.site-content { float: left; width: 67.9245283019%; /* 720px at 1060px */ }
.widget-area { position: absolute; text-indent: -200px ; width: 26.4150943396%; /* 280px at 1060px */ }
.main-navigation li a {line-height: 2.2; }
.main-navigation {margin-top: 12px; margin-top: 0.857142857rem; }
.entry-header .entry-title { font-size: 1.3rem; margin-top: 1.2rem; }
.entry-header {margin-bottom: 12px; margin-bottom: 0.857142857rem; }
}
.widget-area .widget a {text-decoration: none; }
a:hover {font-weight: bold; }
.widget-area .widget a:hover {
color: #6a6a6a;
}



/* Minimum width of 960 pixels. */
@media screen and (min-width: 960px) {
body, body.custom-background-empty{ background: #fff; }
html body .site { box-shadow: none; margin-top: 0; margin-bottom:0; }
footer[role="contentinfo"] { max-width: 1060px; }
}


/*-- start IE8 --*/
.ie .site { max-width: 1060px; }
.ie .site-logo { text-align: left; }
.ie body, .ie body.custom-background-empty{ background: #fff; }
html.ie body .site { box-shadow: none; margin-top: 0; margin-bottom:0; }
.ie footer[role="contentinfo"] { max-width: 1060px; text-align: right; }
.ie .site-header { margin-bottom: 0; }
.ie .site-content { float: right; width: 67.9245283019%; }
.ie .widget-area { float: left; width: 26.4150943396%; }
.ie .site-content article { border: 0; }
.ie #respond form p.form-allowed-tags { display: none; }
.ie .page-template-project-showcase-php .site-content { width: 30.1886792453%; }
.ie .page-template-project-showcase-php .widget-area { width: 16.9811320755%; }
.ie .page-template-project-showcase-php .showbox { float: left; width: 47.1698113208%; margin: 24px 2.83018867925% 0; }
.ie .showbox .slideshow-wrapper .pager img { width: 60px; }
/*-- end IE8 --*/