Thanks for teaching me how to use ThemeMagic for tasks such as changing module width. I never used it before.
The frontpage now looks almost perfect, on both desktop and mobile screen, but I still need to solve a couple of problems.
1. The module "Slideshow", the first module in "top-1" position on the frontpage, is supposed to be displayed in full width rather than having the right half being truncated.
2. The three ACM modules "Our Partners", "Statistics" and "They said it", all in "top-1" position on the frontpage, are no longer visible at all, neither on the desktop nor on the mobile.