CSS layout issues

When the browser viewport is at 1166 pixels wide or less or at a responsive viewport size, the CSS layout in the backend gets messed up big time. This screenshot has browser viewport at 1166 pixels wide using the Twenty Twelve theme. https://i.imgsafe.org/c5cf11951d.png . This plugin needs some front end dev help.

https://ww.wp.xz.cn/plugins/wedevs-project-manager/