Improve popup UI

[xyaman]

The UI works fine in most cases, but there are some things I think it can improve user experience as well fix some bugs related. Here are some ideas:

• Get rid of the hiragana next to the word and use the pitch accent graph below the word, or put furigana above the word instead.
• Set a maximum width and height for the popup, so it doesn't go off-screen and takes up less space (ex. mobile devices). This would require some CSS changes.

If I come up with more ideas, I'll add them here. Let me know what you think, and I could even start working on these changes.