Spinner Overlay Bootstrap 4 Card Body Only - Flex Alignment

Question

Trying to vertically and horizontally align a spinner in a bootstrap 4 card body.

I have tried my-auto and justify-content-center & align-items-center, I am missing something.

I have checked by display types and I believe my displays of absolute are correct

I have also checked my positions and I believe I am using flex correctly.

My goal is to load the spinner on the body on any card vertically and horizontally.

What am I over looking?

CodePen: https://codepen.io/sterling415/pen/xBErWV

HTML:

<div class="card">
  <h5 class="card-header">Featured</h5>
  <div class="card-body justify-content-center align-items-center">
                <div id="overlay" onclick="off()">
                <div id="justify-content-center align-items-center">
                    <div class="spinner"></div>
                </div>
            </div>
    <h5 class="card-title">Special title treatment</h5>
    <p class="card-text">With supporting text below as a natural lead-in to additional content.</p>
     <button type="button" class="btn btn-primary" onclick="on()">Turn on overlay effect</button>
  </div>
</div>      

    </div>
</div>

CSS:

.spinner {
  height: 60px;
  width: 60px;
  margin: auto;
  display: flex;
  position: absolute;
  -webkit-animation: rotation .6s infinite linear;
  -moz-animation: rotation .6s infinite linear;
  -o-animation: rotation .6s infinite linear;
  animation: rotation .6s infinite linear;
  border-left: 6px solid rgba(0, 174, 239, .15);
  border-right: 6px solid rgba(0, 174, 239, .15);
  border-bottom: 6px solid rgba(0, 174, 239, .15);
  border-top: 6px solid rgba(0, 174, 239, .8);
  border-radius: 100%;
}

@-webkit-keyframes rotation {
  from {
    -webkit-transform: rotate(0deg);
  }
  to {
    -webkit-transform: rotate(359deg);
  }
}

@-moz-keyframes rotation {
  from {
    -moz-transform: rotate(0deg);
  }
  to {
    -moz-transform: rotate(359deg);
  }
}

@-o-keyframes rotation {
  from {
    -o-transform: rotate(0deg);
  }
  to {
    -o-transform: rotate(359deg);
  }
}

@keyframes rotation {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(359deg);
  }
}

#overlay {
  position: absolute;
  display: none;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0,0,0,0.5);
  z-index: 2;
  cursor: pointer;
}

JS:

function on() {
  document.getElementById("overlay").style.display = "flex";
}

function off() {
  document.getElementById("overlay").style.display = "none";
}

Answer 1

Change <div id="justify-content-center align-items-center"> to

<div class="w-100 d-flex justify-content-center align-items-center">

See it in action below:

function on() {
  document.getElementById("overlay").style.display = "flex";
}

function off() {
  document.getElementById("overlay").style.display = "none";
}

.spinner {
  height: 60px;
  width: 60px;
  margin: auto;
  display: flex;
  position: absolute;
  -webkit-animation: rotation .6s infinite linear;
  -moz-animation: rotation .6s infinite linear;
  -o-animation: rotation .6s infinite linear;
  animation: rotation .6s infinite linear;
  border-left: 6px solid rgba(0, 174, 239, .15);
  border-right: 6px solid rgba(0, 174, 239, .15);
  border-bottom: 6px solid rgba(0, 174, 239, .15);
  border-top: 6px solid rgba(0, 174, 239, .8);
  border-radius: 100%;
}

@-webkit-keyframes rotation {
  from {
    -webkit-transform: rotate(0deg);
  }
  to {
    -webkit-transform: rotate(359deg);
  }
}

@-moz-keyframes rotation {
  from {
    -moz-transform: rotate(0deg);
  }
  to {
    -moz-transform: rotate(359deg);
  }
}

@-o-keyframes rotation {
  from {
    -o-transform: rotate(0deg);
  }
  to {
    -o-transform: rotate(359deg);
  }
}

@keyframes rotation {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(359deg);
  }
}

#overlay {
  position: absolute;
  display: none;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 2;
  cursor: pointer;
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet"/>
<div class="container">
  <div class="row">

    <div class="card">
      <h5 class="card-header">Featured</h5>
      <div class="card-body justify-content-center align-items-center">
        <div id="overlay" onclick="off()">
          <div class="w-100 d-flex justify-content-center align-items-center">
            <div class="spinner"></div>
          </div>
        </div>
        <h5 class="card-title">Special title treatment</h5>
        <p class="card-text">With supporting text below as a natural lead-in to additional content.</p>
        <button type="button" class="btn btn-primary" onclick="on()">Turn on overlay effect</button>
      </div>
    </div>

  </div>
</div>

Codepen