Uphill sprint repeats for runners

Build me a 30-minute uphill sprint-repeat session for an intermediate runner on a 6-10% grade hill that takes about 20-25 seconds to sprint up. Structure it as: (1) Warm-up: 10 min easy jog in Zone 1-2 (conversational, roughly 60-70% of max HR), then 3 progressive strides on the flat of about 15 seconds each building from jog to ~90% effort, walking back between. (2) Main set: 8 hill sprints of 20 seconds each at hard, near-maximal but controlled effort (not an all-out fall-over sprint - aim for fast, powerful turnover with good form). Walk slowly back down the hill for FULL recovery between reps, about 2-3 minutes each so I feel fresh before the next one. If form or speed drops noticeably, tell me to stop at 8 rather than push to 10. (3) Cool-down: 5 min easy jog plus light walking. Give me cue reminders for posture (tall, drive the arms, push off the ground) and tell me to keep this to once a week, not on back-to-back days with hard runs.