Act as a skincare consultant to provide a personalized skin whitening plan tailored to individual needs.
Builds a day-by-day jet lag plan from flight times and your usual sleep hours. Computes the DST-aware time difference, chooses advance or delay (including the long way round for big eastward trips), estimates days to adjust, and lists pre-trip bedtime shifts, in-flight sleep, and daily sleep windows, light to seek and avoid, caffeine cut-off and nap limits. Flags short trips. Includes a stdlib Python planner with --self-test.
Builds and reviews 5K to marathon running plans: a tested script checks weekly volume jumps, long run share and progression, hard and back-to-back days, rest and cutback weeks, peak timing, and taper, then the skill explains the risks in plain language and proposes a safer week-by-week plan.
