A 53-square-meter flat with the described layout would be compact but functional, designed to maximize space and utility. Here's a breakdown of how it might be arranged:

### Main Room:
- **Size & Function**: This is likely the largest room in the flat, serving as a multi-purpose living space. It could have enough room for a small sofa, a couple of chairs, a coffee table, and possibly a small dining area. Depending on the layout, the room might also include a workspace or a TV corner.
- **Closets**: The three layers of closets could be integrated along one wall or in a designated wardrobe area. These might be deep built-ins, providing ample storage for clothes, linens, and other items. The three layers may suggest stacked shelving, hanging rods, or drawers, utilizing the height of the wall for efficient storage.

### Kids' Room:
- **Size & Function**: The kids’ room would be cozy, with enough space for a bed, perhaps a small desk, and a few toys or play items. Depending on the age of the children, there could be additional furniture like a bookshelf or toy storage.
- **Closets**: The two layers of closets in the kids' room might consist of a combination of hanging space for clothes and lower cabinets or drawers for toys and other items. This would be designed for accessibility and organization, especially if it's meant for younger children.

### Bathroom with Toilet:
- **Size & Layout**: The bathroom is likely compact but efficient, with a shower, toilet, and possibly a small sink. Given the limited square footage, the layout would be optimized with space-saving fixtures like a corner shower or a sliding door. The room might have a few shelves or a small cabinet for toiletries and towels.

### Kitchen at the Entrance:
- **Size & Function**: Positioned near the entrance, the kitchen would likely be a galley style or have a compact setup, possibly with a small refrigerator, a stove, and a sink along one wall. There might be overhead cabinets for storage and some counter space for meal preparation. The kitchen could also have a small dining area or breakfast bar if space allows. It would be designed to be efficient, with a focus on practical, everyday cooking.

Overall Design:
The flat would likely make use of clever storage solutions, like multifunctional furniture or built-ins, to maximize the available space. Light colors on the walls and smart placement of mirrors or windows would help make the apartment feel more spacious. The flow between rooms would be designed to feel open and cohesive, with a focus on both comfort and practicality in the layout.

While each room would be compact, the use of layered storage and thoughtful design elements would make the flat feel organized and livable, even with the limited square footage.