In an attempt to improve kavana (intent) in prayer would like to study a perush (commentary) which explains the shemonei esrei in details (pshat of each word and maybe a bit more). can anyone recommend something online for this?

Inspired by a story I read of R.Elyah Lopian: A non-religious Jew who went to visit Rabbi Lopian's yeshiva during prayer time was asked afterwards about what he saw and replied: "everyone was praying except for the Rabbi who was talking with someone"

after trying this, I found I didn't understand enough some of what I was uttering of the shemonei esrei