Bootstrap fit column with height of two rows

Question

I'm trying to make calculator and made perfect alignment for what I need, except I can't fit one last button. I need it to be the height of two rows, but every time I directly change its height, rows below get into problems too.

Here's my current code, I don't really know how to go about this problem.

<div
  id="root"
  className="container d-flex flex-row justify-content-center align-items-center"
>
  <div id="main" className="container border">
    <div className="row">
      <button className="col btn btn-primary">TEST</button>
      <button className="col-3 btn btn-primary">TEST</button>
      <button className="col-3 btn btn-primary">TEST</button>
    </div>

    <div className="row row-cols-4">
      <button className="col btn btn-primary">TEST</button>
      <button className="col btn btn-primary">TEST</button>
      <button className="col btn btn-primary">TEST</button>
      <button className="col btn btn-primary">TEST</button>
    </div>

    <div className="row row-cols-4">
      <button className="col btn btn-primary">TEST</button>
      <button className="col btn btn-primary">TEST</button>
      <button className="col btn btn-primary">TEST</button>
      <button className="col btn btn-primary">TEST</button>
    </div>

    <div className="row row-cols-3">
      <button className="col-3 btn btn-primary">TEST</button>
      <button className="col-3 btn btn-primary">TEST</button>
      <button className="col-3 btn btn-primary">TEST</button>
    </div>

    <div className="row row-cols-2">
      <button className="col btn btn-primary">TEST</button>
      <button className="col-3 btn btn-primary">TEST</button>
    </div>
  </div>
</div>

Answer 1

Generally, for the full height, you use .h-100 but this might not work for you and I have used bootstrap-4 and for that, the structure for the calculator should be like ...

black boxes are rows and white are columns.

you don't have to use height .h-100 if this structure also works for bootstrap-5.

k boxes are rows and white are columns.
<div id='root' className='container d-flex flex-row justify-content-center align-items-center'>
        <div id='main' className='container border'>
        <div className='row'>
            <button className='col btn btn-primary'>TEST</button>
            <button className='col-3 btn btn-primary'>TEST</button>
            <button className='col-3 btn btn-primary'>TEST</button>
        </div>

        <div className='row row-cols-4'>
            <button className='col btn btn-primary'>TEST</button>
            <button className='col btn btn-primary'>TEST</button>
            <button className='col btn btn-primary'>TEST</button>
            <button className='col btn btn-primary'>TEST</button>
        </div>

        <div className='row row-cols-4'>
            <button className='col btn btn-primary'>TEST</button>
            <button className='col btn btn-primary'>TEST</button>
            <button className='col btn btn-primary'>TEST</button>
            <button className='col btn btn-primary'>TEST</button>
        </div>
        
        <div class="row row-cols-2">
          <div class="col">
              <div className='row row-cols-3'>
                <button className='col-3 btn btn-primary'>TEST</button>
                <button className='col-3 btn btn-primary'>TEST</button>
                <button className='col-3 btn btn-primary'>TEST</button>
              </div>

            <div className='row row-cols-2'>
                <button className='col btn btn-primary'>TEST</button>
                <button className='col-3 btn btn-primary'>TEST</button>
            </div>
          </div>
          
          <div class="col">
          <div className='row row-cols-1'>
                <button className='col btn btn-primary'> = btn</button>
            </div>
          </div>
        </div>
        
            
        </div>

I think this will help.

Answer 2

you need to restructure your rows and columns, try this >>

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous" />


<div id='root' class='container d-flex flex-row justify-content-center align-items-center'>
  <div id='main' class='container border'>
    <div class='row'>
      <button class='col btn btn-primary'>TEST</button>
      <button class='col-3 btn btn-primary'>TEST</button>
      <button class='col-3 btn btn-primary'>TEST</button>
    </div>

    <div class='row row-cols-4'>
      <button class='col btn btn-primary'>TEST</button>
      <button class='col btn btn-primary'>TEST</button>
      <button class='col btn btn-primary'>TEST</button>
      <button class='col btn btn-primary'>TEST</button>
    </div>

    <div class='row row-cols-4'>
      <button class='col btn btn-primary'>TEST</button>
      <button class='col btn btn-primary'>TEST</button>
      <button class='col btn btn-primary'>TEST</button>
      <button class='col btn btn-primary'>TEST</button>
    </div>

    <div class='row row-cols-4'>
      <div class='col-9'>

        <div class='row row-cols-3'>
          <button class='col-4 btn btn-primary'>TEST</button>
          <button class='col-4 btn btn-primary'>TEST</button>
          <button class='col-4 btn btn-primary'>TEST</button>
        </div>

        <div class='row row-cols-3'>
          <button class='col-9 btn btn-primary'>TEST</button>
          <button class='col-3 btn btn-primary'>TEST</button>
        </div>

      </div>
      <div class='col-3'>
        <div class='row' style='height: 100%'>
          <button class='col-12 btn btn-primary'>TEST</button>
        </div>
      </div>
    </div>

  </div>