Act as a certified personal trainer with 10+ years of experience specializing in hypertrophy training. Design a detailed 4-week workout routine for [BEGINNER/INTERMEDIATE/ADVANCED] lifters aiming to build muscle mass. Include exercises targeting [UPPER BODY/LOWER BODY/CORE], with specific sets, reps, and rest periods for each. Explain the science behind [PROGRESSIVE OVERLOAD/VOLUME TRAINING] and how it applies to this routine. Provide modifications for [HOME/GYM] settings and dietary recommendations to support muscle growth, such as [MACRONUTRIENT RATIOS/MEAL TIMING]. Ensure the routine balances compound and isolation movements while avoiding [OVERTRAINING/INJURY RISKS].