When you are developing a web application for phone, tablet and desktop, is it a good principle to use the same HTML for the three and a separate CSS for each device? is there a case where this would cause problems?
It depends how this is setup. If you are using a template engine then I don't see why would this be a big deal if its a technical decision followed throughout the project. If you are not using a template engine and using Javascript to throw things around (like a bunch of Jquery piled on top of each other) then it becomes an issue.
Are you using any kind of server side framework (Like Django/Rails)?
Are you using any kind of client side framework (like Angular)?
Are you using any kind of layout framework (like Bootstrap)?
Are you using any kind of server side framework (Like Django/Rails)?
Are you using any kind of client side framework (like Angular)?
Are you using any kind of layout framework (like Bootstrap)?