Make FlamingoTheme's 'Variables' area collapsible

The presentation of color theme is not good because we have in the right panel only a mobile view be cause the width of the ifram is smal, and the user can't see well the modifications, for this i propose to make the view to 100% of page and make the panel of modification in position absolute and hide it , if we click in the button we open the panel, see the screenshots

i have make the background as transparent for showing to the user the page.

This allow to user to see the result, he just edit and hide the panel to show the result