.bg-landing{
  background-size: cover;
  background-position: center;
  min-height: 100vh;
  position: relative;
}
.overlay{
  position:absolute;
  inset:0;
  background: rgba(0,0,0,0.55);
  z-index:0;
}
nav, .container{
  position: relative;
  z-index: 2;
}