/** mixins **/
.backgroundColor(@color) {
    background: @color;
}

.devContainer(@left, @right) {
    .dev {
        position: absolute;
        left: @left;
        right: @right;
        width: 100px;
        height: 100px;
    }
}


/** layout **/
#mydiv {
    .backgroundColor(blue);
    .devContainer(30px, 30px);
}