A casual goth is a goth who prefers more subtle way of expressing their gothness and mostly wearing all black suffice their needs. A common casual goth outfit is black jeans, a band t-shirt and a pair of black boots; usually the make up is lighter with focus mainly on the eyeliner or maybe a darker shade lipstick.
Often casual goth can be connected with minimalist goth and soft goth, as all these fashion styles are more mellow and toned down versions of the classical goth.
Dressing casual goth is the hottest trend in 2022 and you probably realized it when so many stars started dressing goth-like and suddenly alternative rock and punk music came back to the mainstream top music charts with a full force!
For me casual goth comes very naturally as I grew up as a shy metal girl and now I still have very conservative wardrobe, so I look at casual goth as the introvert sister of the goth fashion. :) and a very easy style to maintain.
I find that casual goth can easily incorporate also different colors - like ash and grey (especially with a dark print on them), whereas many pure goth girls will refuse to wear anything that is not black.