Modify Column width in collection types detail view

Hello,

The collection Type detail view comes in 2 columns on desktop computers (col-lg-9 and col-lg-3). I would like to change theses bootstrap classes…
I figure out how to modify the leftmenu by copying the component from the node_modules to the root code.
However I haven’t found which component I should overwrite to make these changes.

Any Idea ?
Thanks !

Fred

System Information
  • Strapi Version: 2.3
  • Operating System:
  • Database:
  • Node Version:
  • NPM Version:
  • Yarn Version: