Responsive Collapse Main Menu Hide your main menu in a collapible wrapper depending on screenwidth.
To add a responsive collapse main menu instead of the default "off canvas" mobile menu which reacts to screenwidth simply set/remove the following classes on the following elements:
- 
                1 
                
.navbar-toggler: add the attributedata-toggle="collapse". - 
                2 Add the class 
                
.flex-lg-lastto the last.header-blockelement within.header > .header-inner - 
                3 Add the class 
                
.navbar-expand-collapseto the.navbar-expand-*element.