how can i make bootstrap sm break point manually code example

Example 1: col offset in bootstrap

.col-md-3 .offset-md-3

Example 2: offset bootstrap

$grid-breakpoints: (
  xs: 0,
  sm: 480px,
  md: 768px,
  lg: 1024px
);

$container-max-widths: (
  sm: 420px,
  md: 720px,
  lg: 960px
);