Menu background disappears upon re-sizing screen

I am using the Genesis parent theme and the Picture Perfect real estate child theme. On the Home page of my site: http://www.TeamMilgram.com the sidebar menu lost its background. This only happened on the Home page but none of the other pages. I applied CSS code to add a background back (see below):

body > div.site-container > div > div > aside {
	background-color: rgba(255,255,255,.7);
}

However, when I add this background two things happen:
1) It adds the background color to this side menu on EVERY page, which means the already existing background is whiter and less opaque.
2) When the menu is re-sized (viewing it on mobile) the background on the top of the menu on the Home page disappears.

I am slowly figuring out that the Home page sidebar background needs to be set at the parent theme level. Can you help? Thanks.