To start with would you be willing trying inputing Claude with the following instructions? No rounded borders, no excessive padding/margins, no rotated cards, no excessive shadows. More compact/dense ui but also increase base font size a little bit. Make the dark ui the default, use a less neon green color on dark mode, contrast is not great, same for the foreground color. A little nit: On mobile there's an annoying horizontal scrollbar.
Maybe you have fun saying if it converts better or not! I'm fan of a/b testing
If you do let me know ;)