CSS edits done by Marv and Vaid. The board will look like this:
1. Go here. Ensure that "Display recent topics" is enabled, the location is set to "Show on side" and the number is set to 14.
You're technically done after this, but the next steps will ensure that the forum descriptions do not take more than one line, as well as changing the color of the horizontal lines. If you choose not to follow them, I recommend increasing the number of topics a little.
2. Install the Stylus add-on (for Firefox or Chrome) or an alternative of your choice. I do not recommend Stylish. The next steps will assume you're using Stylus, but it should be easily replicated with similar add-ons as well.
3. Click the Stylus icon and choose to write a style.