This button is already shown on desktop devices, so this code is not break anything, and at the same time, you don’t need to add it twice for mobile and mobile landscape custom CSS areas.
one more thing, if I update the theme in the future, do we need to add the codes again, or should use a child theme for that,
or don’t need anything to do
Custom CSS area in Theme Settings, designed especially for storing custom code and will be staying the same after theme updates as other configured theme settings options.
Thanks for the information, so you mean if there is a big code, then it will not be added to the Custom CSS area,
and it will add to other location or something like that