making everything wider

Why does this have to be sooooo hard. All I want to do is make everything on my site wider.
Add CSS to the theme, they say – doesn’t work.
Choose a theme with wider settings- tried that – my site doesn’t have the Document pane, only Page, and there is no option to choose the wider setting.
Add CSS and then put that onto each block. well that works with one, but nothing else.
Make them a block and make the block wider, well that doesn’t work if something in the block is bullet points.
Rant over.

The page I need help with: [log in to see the link]