I use screens before bed but analyze: can I make it less disruptive? Map the screen variables: brightness, content, duration, blue light. Calculate: if I optimized all variables, could I use screens without major sleep disruption? Show me the harm reduction: these settings if I must use screens. Give me the guidelines: this duration, this brightness, these content types are least harmful. Include: whether complete elimination is necessary or optimization is sufficient, and least disruptive screen use.