mdb-ui-kit/scss/variables/bootstrap/_spacing.scss

// Spacing
//
// Control the default styling of most Bootstrap elements by modifying these
// variables. Mostly focused on spacing.

$spacer:                     .5rem !default; // 1rem !default;    // $form-group-margin-bottom uses $spacer-y.  Decided to try this globally and see how it works out.
//$spacer-x:                   $spacer !default;
//$spacer-y:                   $spacer !default;
//$spacers: (
//  0: (
//    x:   0,
//    y:   0
//  ),
//  1: (
//    x:   $spacer-x,
//    y:   $spacer-y
//  ),
//  2: (
//    x:   ($spacer-x * 1.5),
//    y:   ($spacer-y * 1.5)
//  ),
//  3: (
//    x:   ($spacer-x * 3),
//    y:   ($spacer-y * 3)
//  )
//) !default;