I am looking to fix my second full width image (the one in the middle of the page) so that is fits horizontally the same as the one above in the header image. Can somebody double check my CSS so see if it is correct. It needs to auto resize to fit the screen like the header image above. When i view it on mobile it is not fitting correctly. Thanks for taking a look.
.fullWidthSectionBG {
background-image: url('http://static.squarespace.com/static/513d5347e4b0abff73be5264/t/519c45c4e4b084baf13d7e27/1369195972115/rocktruck2.jpg');
border-bottom: solid 1px #ddd;
border-top: solid 1px #ddd;
margin-left: -1600px;
margin-right: -1600px;
padding-top:20px;
padding-bottom:330px;
overflow: hidden;
background-position: center;
background-repeat: no-repeat;
background-size: auto;
}