.u-section-1 .u-sheet-1 {
  min-height: 1063px;
}header {
  position: fixed !important;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 9999;
  background-color: white; /* or your menu background */
}
body {
  padding-top: 60px; /* adjust to your header height */
}