Hello,

Fonts: As I told you, your have Montserrat already built in. You have set Montserrat from your custom (and have not uploaded all the files that is why custom does not work) and you have not specified “Cyrillic” As the result, font did not work. I have set the Google Montserrat, I have set Cyrillic and it works now.

Product grid Please add this code to the Theme Settigns > Custom CSS > Mobile/landscape:

.basel-products-holder .col-xs-6{
    width:100%;
}

Instagram It is a slider and it is not possible to change with CSS. Duplicate the column with Instagram and set the visibility of columns for different devices.
1. http://prntscr.com/j4fho7
2. http://prntscr.com/j4fio2

Is it possible to set margins differently for desktop and mobile? Yes, it is possible. You need to insert the class into the element and show me the screen and page URL. I will provide custom CSS.

Best Regards