Raise the floor. It's worth the money to eliminate a safety hazard.

it's a bit problematic. if you have 'normal' windows at 'normal' height they arent tempered glass like sliding doors are; suddenly they will be close to the floor and the same people falling down the stairs will be falling through window glass. ouch!

also, wall switches and outlets will be at the wrong height.

so, it's an expensive fix that results in less ceiling height. i'd consider for your next party cordon off some of the width of steps going to the room and serve less alcohol.*

we had a sunken living room with this problem, we closed off one of the entries to the room with a folding table of food.

*wink