@map: { @width: 400px; @colors: { toolbar-background: red; toolbar-foreground: white; } }; #ns { .mixin() { @height: 200px; } } @breakpoints: { mobile: 320px; tablet: 768px; desktop: 1024px; }; @media (min-width: @breakpoints[mobile]) { .toolbar { width: @map[@width]; height: #ns.mixin[@height]; background: @map[@colors][toolbar-background]; color: @map[@colors][toolbar-foreground]; } }