Example sentence: I did a surface-level study of German grammar.
This would mean that I didn't go too deep in my study of German grammar; I stayed at the surface level and got just a basic overview.
My guesses would be somehow joining two words: surfacnivela, or surfaconivela, or surfaco-nivela. I can't find any word like this in the dictionary and I'm not sure about all the rules regarding the joining of two words.
Or, I can use the word malprofunda. But, I'm not sure if that word conveys the same meaning as surface-level does in English.
My attempts:
1) Mi faris malprofundan studon de Germana gramatiko.
2) Mi nur malprofunde studis la Germanan gramatikon.
How should I say this?