I have bootstrap grid in some pages, which I’ve made visibale in the editor by styling in editor styles.

Is there a way to make the column div not removable in visual editor, kind of like how you can’t delete a table cell with a backspace. So that when a client deletes the text in a div and keeps pressing the backspace it wont delete the div itself? However I do want the code to be editable when you switch to Text tab.

Also is there a way to make an entire div read only so that it could not be edited in the visual tab?