[woolion]

You OS system theme is dark, so the page uses a dark theme. However, the math is rendered in black... The CSS for MathJAX `mjx-container[data-theme="dark"]` should include to put a white background to avoid this issue. Note that in the upper right of the page, you can force the light version.

That's one reason why I generally rely on the Dark background and Light text extension, as in such cases it's obvious the readability wasn't checked.