fix: Clean up focus mode

[alexandersmanning]

Bit of a hack for this, but a cleanup of the focus mode styles so it looks a bit more presentable. We can come back to this to better improve the CSS.

This:

1. Better aligns the text with the sidebar
2. Move the sidebar to the left as a hack. This is due to the border being on the right which looks a bit odd
3. Fixes the issues with text expanding when there is only a sentence or two
4. Evenly spaces the words regardless of annotation such as filler
5. Adds scrolling (done somewhat hackily)

Before

After