@function top($box) {
    @return parsebox($box, 1);
}

@function right($box) {
    @return parsebox($box, 2);
}

@function bottom($box) {
    @return parsebox($box, 3);
}

@function left($box) {
    @return parsebox($box, 4);
}

@mixin no-selection() {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}