  <h1 class="h3 fw-400 example-title">Navbar expand on mobile</h1>
                <p>This nav expands on all devices, even smartphones.</p>
              </div>
              <div class="card mb-3" id="example">
                <div class="card-header">
                  <ul class="nav nav-tabs card-header-tabs">
                    <li class="nav-item"><a class="nav-link active" href="#">Example</a></li>
                  </ul>
                </div>
                <div class="card-body">
               