Mobile spacing issue with fixed header in Brine 7.0

Site URL: https://www.etailmaven.com/

Hi All,

My site is built using the Brine family Mojave template 7.0.

I have custom CSS code that fixes the header - which does 99% of what I want it to do.

However, I have to put spacers in the first page of each nav point to keep the content from appearing under the header for different screen resolutions - ie:  larger screens need more space at the top.  This solution looks OK on desktop but on mobile there is a lot of space between the header and the content on the pages other than the homepage.  

Is there a way to modify this code to resolve?  Thanks in advance for the help.

.Header.Header--top {
     position: fixed;
     top: 0;
     left: 0;
     width: 100%;
     margin: 0 auto;
     z-index: 9999;
 }