无法弄清楚为什么这个页面在Firefox中看起来很糟糕？在Chrome / IE中看起来不错

This is a page I've been working on for quite some time and I can't figure out why the index page looks so bad in Firefox. All the other pages seem to be just fine. I just finished the simulation page and programmed the whole javascript file but I am so bad at HTML. Please note I started with a template (lots of changes since then). Can anyone guide me in the right direction please?This is a page I've been working on for quite s