Toggle device toolbars

[YuriAmancio]

Dear all,
anyone knows why my layout looks as I inted when I resize my viewport but when I used toggle device toolbars they don’t apply my code.

The second image is my viewport resized and coded applied.

[EpikNohVuh]

html code? css code?

[YuriAmancio]

The code below is for the header, which will change according to the screen size.
I made two headers…one for mobile, and one for tablet and desktop.
When one header is showing, the other is hidden.

Here is the code for tablets and desktop: