#25789: Gap & BR Top Header Update 2
- Trial and error for codes of CSS and JS 
- Clarifying task given 
Nav section should overlay the 1st banner changing the background opacity to 0.
Nav background changes to white on hover. 
Nav should not be fixed on scroll down
Nav should appear with the white background on scroll up.
interchange the Promo banner and the main navigation.
- Redesigning its new look by CSS codes 
- Redevelopment of functions of JS