Looking to create a template with a background on the left side that extends to the edge of the page within an 8 of 12 bootstrap columns setup. The remaining 4 columns on the right will not have a background. This layout should be responsive, stacking on top of each other on mobile screens. I need to avoid using a fluid container for 100% width and instead keep the content within the 12 columns with padding on the left.
Has anyone come across good examples of this design?
I'd prefer not to use the ::before pseudo-element, but I'm open to it if necessary.
Refer to the screenshot for a visual representation: the purple represents the expanding left background, white is the page background, and yellow indicates the 12-column grid.