Whimsical cat mansion, modern minimalist design, sleek lines, large windows, sliding glass doors, open-plan living area, cozy nooks, scratching posts, carpeted tunnels, hidden hideaways, feline agility course, food and water stations, litter box area, natural wood accents, plush cushions, soft blankets, warm lighting, comfortable resting areas, cat trees, observation decks, bird-watching windows, sunny spots, quiet atmosphere, serene surroundings, lush greenery, outdoor enclosure.