Do epilogues have to be long like a regular chapter is یا can they be short (ex: 300-400 words)

How about just about two pages

I think which ever آپ prefer. There is no law stating how long a epilogue has to be. It can be a short chapter یا a paragraph یا whatever. It's all up to you.

They can be however long آپ want but they are normally shorter than normal chapters.