Playroom, cinema and guest room

We want to design a room where we can have a 65’ TV screen hidden behind some cabinetry with storage space. This will be in the wall where the main brown oak door is.
We want to use it almost as cinema room at night.

The cabinetry needs children height storage.

We also need to have sofa beds that can be used by children during day, and by overnight guests. We want a design that is easy to turn into a guest space if needed.

Inspiration: We like Scandinavian design, clean, natural materials, greens, whites, woods-oak. If anyone can come with Ikea-type design and furniture, that is good.