The website looks great on desktop, but for mobile devices it could use some tweaks.

The "tribes" page for instance looks like this on Iphone 6S:

(image 1 provided by Winterlynn below)

The 80% width makes it much too narrow and annoying to read, as well as the padding, and there's too much margin between the banner image and the content. I would change it more towards something like this:

(image 2 provided by Winterlynn below)

There's also a problem with images. Because they don't have a max-width setting, they get cut off on this screen size:

(image 3 provided by Winterlynn below)

The responsive website could use a pass on the margins in general, there's too much vertical space between most content blocks.