Evaluating a Mat-Based Biometric Vibration System for Sleep and Daily Recovery

The goal of this randomized clinical trial is to learn whether a low-frequency "kinetic wellness" mat (a comfortable mat that gently vibrates) can improve stress recovery, sleep quality, mood, and attention in healthy adults ages 18-45. The main questions it aims to answer are: * After 3 weeks, does regular use of the vibrating mat increase heart rate variability (a noninvasive marker of the body's ability to recover from stress) and improve sleep, mood, perceived stress, and anxiety compared with no mat use? * Do patterns of resting brain activity (measured with EEG) and heart rate variability (HRV) change from before to after the program, and are those changes related to each other? Researchers will compare two groups: an Experimental group that uses the vibrating mat at home for 3 weeks, and a Control group that does not use the mat. Participants are randomly assigned to a group. Participants will: * Attend two lab visits (\~60 min) for questionnaires, resting heart activity (HRV) and brain activity (EEG), and a brief attention test. * On 3-4 days per week for 3 weeks: * Experimental group: use the vibrating mat for 15 minutes while recording HRV. * Control group: lie quietly for 15 minutes while recording HRV. * Both groups: record HRV for 15 minutes before bedtime and 15 minutes after waking on those same days. * Both groups: complete quick check-ins on feelings (after sessions and the next morning) and log caffeine/alcohol, exercise, and medications.