I think you need play with how you are styling your inputs. While your CSS makes the textboxes look nice, it’s messing up the checkboxes. There’s a way to only select certain inputs. This article may help: CSS forms from w3schools
I looked at your html, and I’m not sure why you have empty attributes:
<label for="" class="checkbox"><input type="checkbox" name="" id="" class=>
Why is there no value for
And fyi, in CodePen, you don’t need to add the
head information. CodePen takes care of all that for you.
Hope this helps.