Fix inability to tap outside modal on mobile

This commit addresses touch target size issues on mobile devices by
adjusting modal margins. The larger margin allows for easier interaction
for modal dialogs by tapping outside the modal area on smaller screens.

Key changes:

- Introduce 30px margin on larger screens and 20px on smaller devices
  around modals, adhering to accessibility guidelines.
- Remove `max-height: 90vh;` in favor of consistent vertical margins,
  centralizing the spacing control via the `margin` property.
- Remove `max-height: 90v;` used to display scroll-bars as the vertical
  margin is now handled by `margin` property in single place.

tests/e2e/no-unintended-layout-shifts.cy.ts

@@ -19,7 +19,7 @@ describe('Layout stability', () => {
             .contains('button', 'Privacy')
             .click();
           cy
-            .get('.modal-content')
+            .get('.modal-content-content')
             .should('be.visible');
         });
       });