To customize the grid columns in your project, locate the _variables.scss file within your-folder/node_modules/bootstrap/scss/ and find the following code:
// Grid columns
//
// Set the number of columns and specify the width of the gutters.
$grid-columns: 12 !default;
$grid-gutter-width-base: 30px !default;
$grid-gutter-widths: (
xs: $grid-gutter-width-base,
sm: $grid-gutter-width-base,
md: $grid-gutter-width-base,
lg: $grid-gutter-width-base,
xl: $grid-gutter-width-base
) !default;
If you wish to adjust the breakpoints for different screen sizes, you can modify the settings using this snippet:
// Grid breakpoints
//
// Define the minimum dimensions at which your layout will change,
// adapting to different screen sizes, for use in media queries.
$grid-breakpoints: (
xs: 0,
sm: 576px,
md: 768px,
lg: 992px,
xl: 1200px
) !default;
@include _assert-ascending($grid-breakpoints, "$grid-breakpoints");
@include _assert-starts-at-zero($grid-breakpoints);