app/node_modules/@angular/material/divider/_divider-offset.scss

// This mixin provides the correct offset for an inset divider based on the
// size of the parent class (e.g. avatar vs icon)
@mixin inset-divider-offset($offset, $padding) {
  $mat-inset-divider-offset: #{(2 * $padding) + $offset};
  margin-left: $mat-inset-divider-offset;
  width: calc(100% - #{$mat-inset-divider-offset});

  [dir='rtl'] & {
    margin-left: auto;
    margin-right: $mat-inset-divider-offset;
  }
}