Bootstrap Forms

.form-control # text input, textarea, select
.form-control-lg # large input
.form-control-sm # small input

.mb-3 # form group spacing
.form-label # form label
.form-text # help text

.form-check # checkbox/radio container
.form-check-input # checkbox/radio input
.form-check-label # checkbox/radio label
.form-check-inline # inline checkboxes

.form-select # styled select dropdown
.form-select-lg # large select
.form-select-sm # small select

.input-group # input with addons
.input-group-text # addon text/icon

.is-valid # valid input styling
.is-invalid # invalid input styling
.valid-feedback # validation success message
.invalid-feedback # validation error message