Any good place for some touching up on 読解 similar to Wikipedia’s Simple English?

Per what the title says. Basically any resources similar to Wikipedia where I can look up things in somewhat in-depth definitions, but sentences are short and concise enough. My reading used to be around N3/N2 level but I have abandoned the language for pretty much 2 years so I think it's due time I get around to using the language again.

Thanks.