Cislunar form elements source code is same as the Bootstrap except checkbox and radio. Read about Bootstrap Forms here .
This demo form is a modified version of this form. The checkbox and radio buttons are modified according to the theme and the source code for these looks like this:
<!-- Radio Buttons --> <div class="form-row"> <div class="form-group col-6 col-md-3"> <div class="form-check"> <label class="form-check-label"> <input class="form-check-input" type="radio" name="gridRadios" id="gridRadios1" value="option1" checked> <span class="cl-checkbox-input"></span> <span class="mb-0">First radio</span> </label> </div> </div> <div class="form-group col-6 col-md-3"> <div class="form-check"> <label class="form-check-label"> <input class="form-check-input" type="radio" name="gridRadios" id="gridRadios2" value="option2"> <span class="cl-checkbox-input"></span> <span class="mb-0">Second radio</span> </label> </div> </div> </div> <!-- Checkbox --> <div class="form-group"> <div class="form-check"> <label class="form-check-label"> <input class="form-check-input" type="checkbox"> <span class="cl-checkbox-input"></span> <span class="mb-0">Check me out</span> </label> </div> </div>