Placeholder

<div class="card w-md-50 w-100">
                            <img src="../assets/images/placeholder/placeholder-4by3.svg" class="card-img-top" alt="...">

                            <div class="card-body">
                            <h5 class="card-title">Card title</h5>
                            <p class="card-text">Some quick example text to build on the card
                            title and make up the bulk of the card's content.</p>
                            <a href="#"
                              class="btn btn-primary">Go somewhere</a>
                            </div>
                            </div>

                            <div class="card w-md-50 w-100" aria-hidden="true">
                            <img src="../assets/images/placeholder/placeholder-4by3.svg" class="card-img-top" alt="...">
                            <div class="card-body">
                            <h5 class="card-title placeholder-glow">
                            <span class="placeholder col-6"></span>
                            </h5>
                            <p class="card-text placeholder-glow">
                            <span class="placeholder col-7"></span>
                            <span class="placeholder col-4"></span>
                            <span class="placeholder col-4"></span>
                            <span class="placeholder col-6"></span>
                            <span class="placeholder col-8"></span>
                            </p>
                            <a class="btn btn-primary disabled placeholder col-6" aria-disabled="true"></a>
                            </div>
                            </div>

<div>
                            <span class="placeholder col-6"></span>
                            <span class="placeholder w-75"></span>
                            <span class="placeholder" style="width: 25%;"></span>
                            </div>

<div>
                            <span class="placeholder col-12 bg-primary"></span>
                            <span class="placeholder col-12 bg-secondary"></span>
                            <span class="placeholder col-12 bg-success"></span>
                            <span class="placeholder col-12 bg-danger"></span>
                            <span class="placeholder col-12 bg-warning"></span>
                            <span class="placeholder col-12 bg-info"></span>
                            <span class="placeholder col-12 bg-gray-100"></span>
                            <span class="placeholder col-12 bg-dark"></span>
                            </div>

<span class="placeholder col-12 placeholder-lg"></span>
                            <span class="placeholder col-12"></span>
                            <span class="placeholder col-12 placeholder-sm"></span>
                            <span class="placeholder col-12 placeholder-xs"></span> 

<p class="placeholder-glow">
                            <span class="placeholder col-12"></span>
                            </p>
                            <p class="placeholder-wave">
                            <span class="placeholder col-12"></span>
                            </p>