A modern teenage witch's bedroom. The room should have a mystical and whimsical atmosphere. Include a cozy bed with a canopy draped in fairy lights, shelves filled with spell books, potion bottles, and magical artifacts. Add a small cauldron on a wooden table with a spell being cast, emitting a soft, glowing light. The walls should have posters of celestial patterns, moon phases, and mystical symbols. Include a window showing a starry night sky with a full moon. Decorate the room with plants, cr