Disappearing divs

While trying to incorporate my L5 in my daily routines, I tried using it for checking my online agenda. I log in to a system that is widely used in Dutch education, called Magister. Although I can log in using my tablet or laptop, it would be really neat to use (one of) the browser(s) on my L5 for this.
Sadly the collapsible divs this website uses wreak havoc on the page layout both the Gnome browser and Firefox manage to produce. The divs don’t properly adapt to the screen width, in the sense that they are way to narrow, and the content is either invisible or spills over the edges of the divs.
Co-workers using androids or iphones don’t appear to have these problems.

What could be going on here? And is there any way to solve it?

It sounds as if the website thinks you are browsing from a PC and not a mobile device. If you use Firefox, this add-on is good when you want to make sure websites serve you the mobile version.

Thanks! I was thinking something like that was happening: the browser on my Windows Phone has a setting to make it act either as a mobile browser or as a desktop one.
I will check out the addon…

No luck just yet, but I will try some more later.