009 Colors-Variables
https://github.com/academind/100-days-of-web-development/blob/32-online-shop/code/03-adding-css-variables/public/styles/base.css

031 JavaScript-Array-Methods
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array

040 products.css-File
https://github.com/academind/100-days-of-web-development/blob/32-online-shop/code/27-outputting-product-details/public/styles/products.css

041 Reference-vs-Primitive-Values
https://academind.com/tutorials/reference-vs-primitive-values

052 Changed-Code-Files
https://github.com/academind/100-days-of-web-development/tree/32-online-shop/code/32-changed-files

054 updateCartPrices-Middleware
https://github.com/academind/100-days-of-web-development/blob/32-online-shop/code/32-changed-files/middlewares/update-cart-prices.js

054 Updated-Cart-Model
https://github.com/academind/100-days-of-web-development/blob/32-online-shop/code/32-changed-files/models/cart.model.js