Electric Lights on Yom Tov

Hi. In middle of the Seder the lights went out. Someone brushed up against the switch. There were still other lights in the room, so we left it alone.
I’m wondering if being that it’s Yom tov, and we cook and use fire, can we also turn the lights back on?

Initially you are supposed to put the lights on before Yom tov where you need them. In this circumstances where you already had lights, but they were accidentally turned off, it is OK to turn the lights back on during Yom Tov.

Would the same logic of it being yom tov, and for cooking we can higher or lower the cooking flame, apply to a dimmer light system as well?

I’m not sure what you’re asking