Playground

<>
  <div className="alert alert-primary">
    <strong>.alert.alert-primary</strong>
  </div>

  <div className="alert alert-secondary">
    <strong>.alert.alert-secondary</strong>
  </div>

  <div className="alert alert-dark">
    <strong>.alert.alert-dark</strong>
  </div>

  <div className="alert alert-light">
    <strong>.alert.alert-light</strong>
  </div>
</>