Dear Agatha,
The “previous/next” buttons work as they normally should by default, i.e. go in the direction of the date the posts were published. The twist is that the list on the portfolio page has the most recent items on top, so it looks like the “previous/next” button goes backward :) In any case, I’ve changed the direction of the buttons so that now they follow the same direction as the portfolio list.
I’ve set the font size of the portfolio list to the same 14px as the filter tags. I’ve also decreased the margin between the top menu and the logo area from 50px to 30px. You can change the last figure to anything you want by going to “Appearance -> Editor”, scrolling to the very bottom of the “style.css” file (should be open by default) and altering the “margin-top: 30px” parameter.
Best,
Andrew | Satori