Static or Fixed Top (contains the logo, menu, login etc)

Hi All,

I'm new to CS-Cart v3 and I'm trying to see how this can be done; I want the header or what is in the “top wrapper” (for instance “my account”, “cart contents” and the menu) to remain fixed. Please refer to these website for the design intent… & .

These are obviously not carts but it's the basic principle of the header being static or fixed.