"Looks really well" or "Looks really good"? [duplicate]

Among other things, well means:
- In a good or proper manner: behaved well.
- Skillfully or proficiently: dances well.
- With care or attention: dressed well.

Good means - Attractive; handsome: good looks.
- Beneficial to health; salutary: a good night's rest.
- Competent; skilled: a good machinist.

While you can say, "you dress very well" (where the verb is dress), you would say "your dress looks really good" (where the verb is looks).

You use "really good" unless you are talking about health. Then you use "really well"

"Good" is an adjective. "Well" is normally used as an adverb, but can also be used as an adjective when referring to someone's state of health. So your second sentence would only make sense if the dress in question was alive and was looking healthy.

You wouldn't use "looking well" except about a person. It usually refers to a person's health, although it can refer to the act of looking, as in

Look well into this, and get back to me.

Since a dress can neither see nor be healthy, looks really well is not applicable.