To save some time on people having to firebug the code quite so much to look up the relevant class to reference with css here is a quick guide to the relevant classes that make up the theme. The indentation represents the hierarchy of the relevant code except from /* different block layouts */ onwards.

/* GUIDE */

Level 1) .region-page-top, #page-wrapper, .region-page-bottom

Level 2 structure) #header-wrapper, #secondary-content-wrapper, #content-wrapper, #page-footer

Level 3) #content-wrapper > #main-content


/* AT Structure Classes */

body.html { }

body.front { }

/* admin bar */

.region-page-top #toolbar { }

#page-wrapper #page { }
	
	/* draw wrapper is a sliding toggle at top of page */
	#draw-wrapper { }

	#header-wrapper { }
	
		#branding { }
		
			#logo { }
			
			hgroup#name-and-slogan {}
			
			h1#site-name {}
			
				h1#site-name a { }
			
		.region-header { }
		
	/* menu */
	
	#menu-wrapper { }
		#menu-bar { }
			
			
	#secondary-content-wrapper { }
			
	
	#content-wrapper { }
	
		section#breadcrumb { }
		
		#columns #content-column section#main-content { }
		
			.region-sidebar-first { }		
			#content { }
			.region-sidebar-second  { }
			.region-content-aside { }
			.sidebar { }
			
	#tertiary-content-wrapper { }
		.region-tertiary-content { }
			.region-secondary-content { }
	
	#page-footer { }
		#footer-wrapper { }
			.region-footer { }

	
.region-page-bottom { }


/* different block layouts */

.two-50 { }
	.region-two-50-top { }
	.region-two-50-first { }
	.region-two-50-second { }
	.region-two-50-bottom { }

.three-3x33 { }
	.region-three-33-top { }
	.region-three-33-first { }
	.region-three-33-second { }
	.region-three-33-third { }
	.region-three-33-bottom { }
	
.four-4x25 { }
	.row-1 { }
		.region-four-first { }
		.region-four-second { }
	.row-2 { }
		.region-four-third { }
		.region-four-fourth { }

.five-5x20 { }
	.row-1 { }
		.region-five-first { }
		.region-five-second { }

	.row-2  { }
		.region-five-third { }
		.region-five-fourth { }
		.region-five-fifth { }


/* blocks that come with commerce kickstart */

	/* shipping cart */	
	#block-views-shopping-cart-block { }
	.block-shopping-cart-block { }
		.view-shopping-cart { }
	
	/* payment methods */		
	section#block-menu-menu-payment-methods { }
	
	/* shopping cart */		
	section#block-commerce-cart-cart { }
	.block-commerce-cart { }
	
	/* product display */		
	#block-views-exp-display-products-page { }
		form#views-exposed-form-display-products-page { }
	
	/* search */		
	#block-search-form { }
	
	/*main menu block */		
	ul.menu { }
	ul.menu li { }
	ul.menu li a { }