The guide introduces the concept of ambient, task, and accent lighting and explains how imbalance among these layers can create shadow-heavy environments. It also discusses wall color reflectivity, ceiling height, and light distribution patterns as critical contributing factors. Readers will gain actionable insights into diagnosing lighting issues and improving brightness perception without necessarily increasing energy consumption. By understanding how lighting interacts with room design elements, users can create brighter, more comfortable living spaces. This document is particularly helpful for homeowners, interior planners, and renovation professionals.