Base salary was locked but I asked for a signing bonus to cover it and they said yes without blinking

Recruiter said the base band was fixed, no room, standard line. Instead of pushing on a number that clearly wasn't moving, asked if a one-time signing bonus was possible to bridge the gap between their offer and what I needed to leave my current job. Took two days to come back, but the answer was yes, no real friction. Learned afterward that a lot of comp bands are genuinely rigid on the recurring number for internal equity reasons but far more flexible on anything one-time. Wish someone had told me that distinction existed before I spent an entire negotiation call arguing about the wrong line item.