- .custom-check is now .form-check.
- .custom-check.custom-switch is now .form-check.form-switch.
- .custom-select is now .form-select.
- .custom-file and .form-file have been replaced by custom styles on top of .form-control.
- .custom-range is now .form-range.
- Dropped .input-group-append and .input-group-prepend. You can now just add buttons
and .input-group-text as direct children of the input groups.
Mikel Martín