custom css for collections

[cj]

I've finally been creating a custom AO3 skin for myself in time for the vast amount of Yuletide reading I plan to do this year, and I've discovered that going to the actual Yuletide collection breaks my header pretty badly because the custom css for the Yuletide collection header overrides my own style. Does anyone know any way to compensate for or fix this?

ETA: Sorted! Thank you!