Full-width feature image on posts

Hi,

I used the code in the documentation to force featured images to be full width when using the default post layout and I adjusted the max width so that the width of the rest of the container would be smaller (1110px) which worked fine. The problem is that now the header container is also full width, and looks bad. I only want the featured image to be full width.

This is the code I used:
/*—————————————–
// CSS – Full-width Featured image
//—————————————-*/

#top.single .container {
padding: 0 !important;
width: 100% !important;
max-width: 100% !important;
}
#top.single .entry-content-wrapper {
max-width:100%!important;
margin:0 auto;
padding:0 50px;
background:gold;
}
#top.single .entry-content {
max-width:100%!important;
margin:0 auto;
}
#top.single .content {
padding-top: 0 !important;
}