:root{--parallax-height:33.333vh;--parallax-base-width:1920;--parallax-base-height:1080;}.parallax{position:relative;height:var(--parallax-height);overflow:hidden;}.parallax--layer{position:absolute;top:50%;left:0;width:100%;height:calc(var(--parallax-base-height) / var(--parallax-base-width) * 100vw);background:none no-repeat scroll 50% 50%;background-size:cover;transform:translate(0,-50%);}