$sticky-offset:                       0 !default;
$sticky-shadow-top:                   0 -.5rem 1rem rgba(0, 0, 0, .15), 0 -.25rem .625rem rgba(0, 0, 0, .15) !default;
$sticky-shadow-bottom:                0 .5rem 1rem rgba(0, 0, 0, .15), 0 .25rem .625rem rgba(0, 0, 0, .15) !default;