In Bernstein-Vazirani algorithm, we can see the application of $CX$ gates from each qubit that represents the bit in state 1, onto the $|-\rangle$ state. It seems clear to me that the $CX$ will apply the $X$ gate if control qubit is in state $|1\rangle$, which basically sounds like querying the black box.
If we have $N$ bits to guess, then we are applying $N$ number of $CX$ gates, which are queries to the black box.
How come is this considered only one guess, then? I thought of the possibility that follows the logic of gates being multiplied together to form one "generalized" guess, but I am not sure whether that's correct logic to follow.