<div class="toast" role="alert" aria-live="assertive" aria-atomic="true">
  <div class="toast-header">
    <img src="..." class="rounded mr-2" alt="...">
    <strong class="mr-auto">Bootstrap</strong>
    <small>11 mins ago</small>
    <button type="button" class="ml-2 mb-1 close" data-dismiss="toast" aria-label="Close">
      <i class="material-icons">close</i>
    </button>
  </div>
  <div class="toast-body">
    Hello, world! This is a toast message.
  </div>
</div>

<div class="toast" role="alert" aria-live="assertive" aria-atomic="true">
  <div class="toast-header">
    <img src="..." class="rounded mr-2" alt="...">
    <strong class="mr-auto">Bootstrap</strong>
    <small class="text-muted">just now</small>
    <button type="button" class="ml-2 mb-1 close" data-dismiss="toast" aria-label="Close">
      <i class="material-icons">close</i>
    </button>
  </div>
  <div class="toast-body">
    See? Just like this.
  </div>
</div>

<div class="toast" role="alert" aria-live="assertive" aria-atomic="true">
  <div class="toast-header">
    <img src="..." class="rounded mr-2" alt="...">
    <strong class="mr-auto">Bootstrap</strong>
    <small class="text-muted">2 seconds ago</small>
    <button type="button" class="ml-2 mb-1 close" data-dismiss="toast" aria-label="Close">
      <i class="material-icons">close</i>
    </button>
  </div>
  <div class="toast-body">
    Heads up, toasts will stack automatically
  </div>
</div>

<div aria-live="polite" aria-atomic="true" style="position: relative; min-height: 200px;">
  <div class="toast" style="position: absolute; top: 0; right: 0;">
    <div class="toast-header">
      <img src="..." class="rounded mr-2" alt="...">
      <strong class="mr-auto">Bootstrap</strong>
      <small>11 mins ago</small>
      <button type="button" class="ml-2 mb-1 close" data-dismiss="toast" aria-label="Close">
        <i class="material-icons">close</i>
      </button>
    </div>
    <div class="toast-body">
      Hello, world! This is a toast message.
    </div>
  </div>
</div>

<!-- Flexbox container for aligning the toasts -->
<div aria-live="polite" aria-atomic="true" class="d-flex justify-content-center align-items-center" style="min-height: 200px;">

  <!-- Then put toasts within -->
  <div class="toast" role="alert" aria-live="assertive" aria-atomic="true">
    <div class="toast-header">
      <img src="..." class="rounded mr-2" alt="...">
      <strong class="mr-auto">Bootstrap</strong>
      <small>11 mins ago</small>
      <button type="button" class="ml-2 mb-1 close" data-dismiss="toast" aria-label="Close">
       <i class="material-icons">close</i>
      </button>
    </div>
    <div class="toast-body">
      Hello, world! This is a toast message.
    </div>
  </div>
</div>