OJS 3 side bar on the left side

Hello,

Looks like the OJS 3 has support for the side bar on the right side only (although the CSS class is named .pkp_structure_sidebar.left). But there is a space on left side of the screen that I would like to use similar as on the OJS2. Can you please let me know how can I enable/use the space on the left side for adding additional content there?

Regards, Primož