Design a minimalist wooden treehouse that seamlessly blends with the surrounding tree. The structure should use natural materials that mimic the texture and color of the tree, creating an organic and harmonious integration. Focus on simple geometric shapes with clean lines, ensuring the treehouse maintains an unobtrusive presence. Prioritize sustainability in both design and construction, making use of eco-friendly materials. The design should emphasize open spaces, large windows, and strategic use of natural light, enhancing the connection between the interior and the natural environment.