I have some widgets installed in a sidebar for my Mantra theme. Everything looks good on a computer screen. However, when the site is viewed on the tiny screen of a mobile, I would like to hide some of the widgets (e.g. a map)? If possible, I would also like to hide some pages too.
You could edit style-mobile.css and add a display: none for the tags/elements you wish to hide.
The thing is you need those elements to have a unique tag/id, and it would be a good idea to make this change via a child theme (some function overriding required) to make the changes stick between updates.