What this Bootstrap Utility API class does
Set the margin top property of an element to a negative value.
Negative margins are not enabled by default. You need to set the Bootstrap SASS variable
$enable-negative-margins to true. To use negative margins, add "n" in front of the normal margin class. So
.mt-n5 for the negative version.
Example usage & available classes
<div class="mt-n1"></div> <div class="mt-n2"></div> <div class="mt-n3"></div> <div class="mt-n4"></div> <div class="mt-n5"></div>
In the example override below, we are adding the additional class of "mt-n6" with a value of "-6rem". Note that you can update Bootstrap's SASS $spacer variable to add additional margin and padding options. This would be a cleaner method to use rather than using the API because any additional values you add to the $spacer variable would automatically be available for all the margin and padding utilities.
"negative-margin-top": map-merge( map-get($utilities, "negative-margin-top"), ( values: map-merge( map-get(map-get($utilities, "negative-margin-top"), "values"), ( n6: -6rem ) ) ) )