Jupyter Notebook Preview Looks Weird

I'm using Pycharm and Jupyter Notebook to learn data science, but the first thing I ran into is this weird font. (This is in the preview screen.)

This isn't the normal font; on my other computer I have PyCharm as well and I'm using Jupyter Notebook on that, and it looks a lot different from this. I only just installed PyCharm on this computer, and I set it to Darcula theme. Then I decided it wasn't for me so I set it to the light theme, and now I have this weird text. Is there any way to fix this?