okay I understand little to nothing about webpages and java etc. , but I like your site. You explain things well, in as easy to understand language as possible. I like the layout, it’s clean, simple and easy to navigate. All things I love when I visit websites.
Only suggestion, unless there is a specific reason for the red theme, you might want to change it. Depending on culture values for colors, red can be seen as very aggressive or dangerous. I suggest Blue, it is seen as competent and responsible. Or if you really want red, maybe choose a darker shade of red, more of a burgandy or wine color.