.page-header { position: fixed; left: 0; margin-top: 0; width: 100%; box-sizing: border-box; -webkit-transition: top 0.6s; -moz-transition: top 0.6s; transition: top 0.6s; } .page-header.off-canvas { top: -59px; } .page-header.fixed { top: 0; z-index: 9999; }