No offense, but your HTML makes me want to vomit. H3 as the child of a OL? Endless pointless classes for nothing? Multiple H1 without SECTION to reset the depth? H2 that aren't starting subsectiions? H3 right after a H1?
LEARN HTML!
Much less all the scripting only elements in the markup where they don't even belong, and manually swapping style from the scripting instead of class handling...
But honestly that seems to be par for the course with so many people using JS these days. They don't know enough HTML or CSS to be using JS yet.