Bootstrap: Input Labels on border

Question

Searched quite a lot, couldn't find anything - am I really the only one?

How do I turn

<div class="form-group">
   <label for="input1" >Username</label>
      <input type="text" class="form-control" id="input1" value="boern">
</div>

Into this (where the label is inline / on the border / stroke):

Aren't there any prefined bootstrap scss tricks or classes that I can used without messing myself with the css like so (the less CSS I write, the better):

<div class="form-group">
   <label for="input1" style="margin-left: 12px; margin-left: 15px; 
                             margin-top: -12px; position: absolute; 
                             background-color: white; border: 2px solid white;">
      Username
   </label>
   <input type="text"  style="height: 3.3rem;" class="form-control" id="input1" value="boern">
</div>

Thanks!

Answer 1

If you are using bootstrap 4 (which I assume) you can achieve "labels on border" with no dirty inline / custom CSS by using a mix of spacing classes -> https://getbootstrap.com/docs/4.5/utilities/spacing/ :

<div class="form-group">
  <label for="input1" class="col-sm-2">
    <span class="h6 small bg-white text-muted pt-1 pl-2 pr-2">Username</span> 
  </label>
  <input type="text" class="form-control mt-n3" id="input1" value="boern">
</div>

The most important here is the negative .mt-n3 margin. It looks like this

demo -> https://jsfiddle.net/nksz9g5e/

Perhaps you want to customize the label font size, .h6 .small is the smallest "native" size I can think of. And perhaps the labels right gutter should be adjusted.

Answer 2

For Bootstrap 5 I manage to implement it as well like so:

<form class="card card-body">
  <div class="row">
      <div class="col px-1 mb-2">
          <label for="input1" class="ms-2 position-absolute" style="margin-top: -0.25rem !important">
              <span class="h6 small bg-white text-muted px-1">Username</span>
          </label>
          <input type="text" class="form-control mt-2" id="input1">
      </div>
      <div class="col px-1 mb-2">
          <label for="input2" class="ms-2 position-absolute" style="margin-top: -0.25rem !important">
              <span class="h6 small bg-white text-muted px-1">Password</span>
          </label>
          <input type="password" class="form-control mt-2" id="input2">
      </div>
  </div>
</form>

If you have enabled negative margins in your SASS you can omit the style attribute in your label tags and just add .mt-n1 to it's class.

Demonstration: https://jsfiddle.net/t4cwnxbh/

It looks like this: