Filling Lines tasks linking matching shapes via ordered, tangle-free threads to fill every grid cell. Strategic sequencing prevents painting yourself into corners, with color-coded pairs adding nuance. Progressive complexity layers rotating icons and portal jumps, testing adaptability. Hint systems guide desperate moments, while streak tracking motivates consistency. Clean aesthetic focuses on pure problem-solving, with gentle animations celebrating flawless fills. A refined daily trainer that transforms simple connections into strategic masterpieces, captivating with elegant escalation and triumphant total coverage.