I made a website, or rather something like a template, so that the client fills his website himself.
I didn’t use breakpoints in the interface of the constructor itself, so as not to burden the client with unnecessary problems and training, but I registered CSS media queries so that the size of the titles would change depending on the screen size.
Here is a demo of the template site: https://demokarkas.htmlplus.ru
The highlight of this work is the product calculation calculator. Where the cost of the product varies not only from the options that the buyer orders, but also from what size of the product will be chosen initially (2, 4, or 8 meters).
The peculiarity of the calculator is that when calculating on smartphones, a fixed panel appears at the bottom of the screen, which displays the change in cost depending on the selected options. This was done for convenience, since on large monitors the calculator interface is visible in its entirety, and on mobile it stretches down and the final amount is only visible when you scroll down the page, which is not very convenient for the site visitor.
View of the calculator on the desktop
Calculator view on mobile
Here is a demo page with a calculator: https://demokarkas.htmlplus.ru/nefela-v2.php
The template uses a lot of different tricks that allow the site customer to easily work with the project and not think about many things.
For example, the H1 heading is substituted automatically. The calculator sends the order, where the name of the selected product is automatically written, depending on which page the order was sent from, and my customer does not need to change the subject of the letter inside the form. Canonical pages are also automatically assigned, depending on how the page is named. In general, the user clones the page, changes the file name and voila - the canonical tag has a different value in the code!
There are a number of interesting solutions, but I'm too lazy to paint)))