Not in great shape lately, so a few small fixes / tweaks:

• Use sans-serif and non-italic fonts for the word definitions in the Vocab Shuffle reviews (for legibility).

• Reduced font size on the Vocab Shuffle flashcards for small screens ( <= 700px ), so the word definitions do not overextend (thanks Francis).

• Fixed the "Exit" links in Vocab Shuffle reviews (back to the Custom Review page).