Not sure I get this right but do you actually want to make it non-responsive – i.e. want the desktop styles at all widths? If that is the case, the simplest way to achieve it is to edit the breakpoint in your theme CSS file “sm-mint.css” from this:
@media (min-width: 768px) {
to, for example, something like this:
@media (min-width: 1px) {