/* Remove structural constraints on the header wrapper */
.pkp_structure_head .pkp_site_name_wrapper,
.pkp_structure_head .pkp_site_name_wrapper a {
    width: 100% !important;
    max-width: 100% !important;
    padding: 0 !important;
    margin: 0 !important;
    display: block !important;
}

/* Force the header logo image to be responsive and full width */
.pkp_structure_head .pkp_site_name_wrapper img {
    width: 100% !important;
    max-width: 100% !important;
    max-height: none !important;
    height: auto !important;
    display: block !important;
}