fixed menu

Hello,

I need help to get my navbar menu fixed on top so that when I scroll down, the menu is still there.
I have tried this css code found with Google but then when I apply the code , on desktop it works fine however on mobile we cannot see the hamburger button of the menu anymore:

#site-header {
height:70px;
z-index:170;
margin:0 auto;
border-bottom:1px solid #dadada;
width:100%;
position:fixed;
top:0;
left:0;
right:0;
text-align: center;

}

Your help would be very much appreciated

• This topic was modified 5 years, 1 month ago by Jan Dembowski. Reason: Moved to Fixing WordPress, this is not an Developing with WordPress topic

The page I need help with: [log in to see the link]