How much money should I give my brother for his belated birthday?

So I didn’t really get anything for my brother’s 20th birthday. I mean I feel bad because I know it’s the thought that counts. I didn’t illustrate my birthday wishes to him except for a happy b-day message on facebook. I’m not working so I don’t have money coming into my pocket. I have money left over from my birthday ($40) and that’s all I have. I thought he would kind of forget, but he just brought up the fact that I didn’t get him anything for his birthday. He’s working and has a job. His birthday was March 7th. Do I give him the $40 dollars that I have? Or should I just give him a happy belated card? Or both? Or any other suggestions?