Sidebar Responsive

I have three themes installed

1) Alante >>> Original Alante
2) Alante2 >>> Copy of Alante whith some changes
3) Alante3 >>> 1:1 of 1)

On a mobile I get the sidebar on the bottom of the content with 1). With 2) the sidebar is not visible, same with 3)

I have tested this with all my plugins and with all plugins de-activated !!! So it is not a plugin conflict.

When I look into the style-responsive.css in all three themes there is the following code:

/* Small Tablets & Larger Phones */
@media only screen and (max-width: 685px) {

	/* Main */
	#pre-header-links-inner,
	#pre-header-social,
	#breadcrumbs,
	#sidebar,
	#intro.option3 .page-teaser,
	#footer-menu,
	.meta-author {
		display: none !important;
        padding: 0 10px;

When I change “display: none” to “display: block” the sidebar is shown on the bottom, but with a small with.

No it comes to my question….

A) How does the theme makes the sidebar in 1) visible with “display: none”?
B) How can I make the sidebar visible in 2) without changing “display none” to “display: block”? <<< This would be the original solution from Alante
C) If I need to change “display: none” to “display: blok”, how can I make the sidebar full with (exactly like the content above, with same spaces)