// ---- // libsass (v3.2.5) // ---- /* first test */ $small: nothing; // fallback for images not uploaded @mixin testSmall($s: null) { @if ($s == nothing) { display: none } @else { background: transparent url(img) no-repeat 50% 50%; background-size: cover; padding-bottom: 94.85%; } } @include testSmall($small); /* second test */ $small: any other value in the world; // link or value for uploaded image @mixin testSmall($s: null) { @if ($s == nothing) { display: none } @else { background: transparent url(img) no-repeat 50% 50%; background-size: cover; padding-bottom: 94.85%; } } @include testSmall($small);