Yes, the site is about maths, mainly about calculus (limits of functions, continuity, derivatives) and it is also about discrete mathematics (basically combinatorics).
The site is simple because I think the content requires that... and because I donยดt know about graphic design.
For the same reason Iโm not sure about the color scheme either, perhaps I should reconsider it, althought I like the background color, I find it pleasant to read... The rest of the colors were chosen later in order to harmonize with it.
Thanks.