Create a feature that allows customers to build a custom pack of 8 items, consisting of a combination of different chocolates. The total number of items in the custom pack should not exceed 8, and the price must be calculated automatically based on the selected products.

1. Enable customers to select a combination of Chocolates for their custom pack.
2. The sum of Chocolates should not exceed 8 items.
3. Display the total price of the custom pack, which should update automatically based on the selected items and their respective quantities.
4. Ensure that the user interface is intuitive and responsive.
5. Provide a brief explanation of your approach, including any tools or frameworks used, and the reasoning behind your choices.