The "Help" button at the top of the page is distorted.
You might consider left justifying the center paragraph on the home page, It's too hard to read as it is.
Make the all of the section headers in the left menu look the same. The top three sections use right aligned text while the "payment methods" is a graphic.
While the layout is clean, you might consider adding some colour to the section headings. Few elements in the page jump out at the user amid all the grey tones.
Make your page headings larger and a different colour. As it stands, the "Privacy Policy" page heading would be more helpful to your users were it inside some styled <h1></h1> tags. In terms of
SEO, you'd soon find that adding the <h1> tags would prove to be very beneficial.
The links in the navigation menu would benefit from underlining or some other means of differentiation.