// Positioning .fixed-top { position: fixed; top: 0; right: 0; left: 0; z-index: $zindex-fixed; } .fixed-bottom { position: fixed; right: 0; bottom: 0; left: 0; z-index: $zindex-fixed; } .sticky-top { @supports (position: sticky) { position: sticky; top: 0; z-index: $zindex-sticky; } }