I have been writing in third person restricted, but I want to write my MC's thoughts/ inner dialog in first person present tense with a past tense tag. Example : The woman stepped closer. Mark pressed his back to the classroom door. This can't be Janet, Mark thought, she's been dead. It's impossible.... I think it feels decent but I personally haven't read anything with that format? Any suggestions, thoughts, criticism?
Thoughts are in present tense, just like dialogue is, and for the same reason. You're reporting what the person thought at that time. You wouldn't say to somebody "Came over here", you'd say "Come over here". And you don't think "Why was I so sad?" but "Why am I so sad?"—unless you're wondering why you were so sad at an earlier time. If the writing is in a less 'close' or 'deep' level it can be in past tense, like this: 'He wondered why this kept happening to him.' Notice for that I stayed in 3rd person, but if you shift into 1st person for thoughts like you did above then you're reporting it exactly as he thought it at the time. 'He wondered why this kept happening to him' isn't directly reporting his immediate thoughts, it's simply telling (narrating) to the reader what he was thinking. And you can use both in a story. It's common to shift in and out of the character's head, to go in closer at times and switch to 1st person, and then pull back out a ways and report what he's thinking in 3rd person.