//====================================
//              FOR LOOP             =
//====================================
.for(@i, @n) {
  .-each(@i)
}

.for(@n) when (isnumber(@n)) {
  .for(1, @n)
}

.for(@i, @n) when not (@i =@n) {
  .for((@i + (@n - @i) / abs(@n - @i)), @n);
}
//--------  End of for loop  ---------//



//=========================================
//              FOR EACH LOOP             =
//=========================================
.for(@array) when (default()) {
  .for-impl_(length(@array))
}

.for-impl_(@i) when (@i > 1) {
  .for-impl_((@i - 1))
}

.for-impl_(@i) when (@i > 0) {
  .-each(extract(@array, @i))
}
//--------  End of for each loop  ---------//






///////////////
// variables //
///////////////
@screen-xs: 0;
@screen-sm: 480px;
@screen-md: 768px;
@screen-lg: 992px;
@screen-xl: 1600px;




@values-array: 0, 5, 10, 15, 20, 21, 22, 23, 24, 25, 30, 40, 50;



// global
@media (min-width: @screen-xs) {
  .make-space(@prefix: xs);
}
// mobile
@media (min-width: @screen-sm) {
  .make-space(@prefix: sm);
}
// tablet
@media (min-width: @screen-md) {
  .make-space(@prefix: md);
}
// desktop
@media (min-width: @screen-lg) {
  .make-space(@prefix: lg);
}
// large screens
@media (min-width: @screen-xl) {
  .make-space(@prefix: xl);
}






// init functions
.make-space(@prefix) {
  .for(@values-array);
  .-each(@value) {
    .@{prefix}-p-@{value}   { padding:        ~"@{value}px"; }
    .@{prefix}-pt-@{value}  { padding-top:    ~"@{value}px"; }
    .@{prefix}-pl-@{value}  { padding-left:   ~"@{value}px"; }
    .@{prefix}-pr-@{value}  { padding-right:  ~"@{value}px"; }
    .@{prefix}-pb-@{value}  { padding-bottom: ~"@{value}px"; }
    .@{prefix}-m-@{value}   { margin:         ~"@{value}px"; }
    .@{prefix}-mt-@{value}  { margin-top:     ~"@{value}px"; }
    .@{prefix}-ml-@{value}  { margin-left:    ~"@{value}px"; }
    .@{prefix}-mr-@{value}  { margin-right:   ~"@{value}px"; }
    .@{prefix}-mb-@{value}  { margin-bottom:  ~"@{value}px"; }

  }
}