Sales and Installation of Plastic Window

About the project:
used SASS preprocessor;
When writing styles used the Mobile-first approach and the media-function min-width;
a network from Bootstrap 4 is used;
in the edge of the page, the BEM name is used for classes;
This project is implemented:
Function of modular windows.
Functional Deposit (TABs)
Forms with sending data to the server.
Calculator form function with the subsequent sending of all entered data.
The function of increasing images when clicking on them.