                      <input type="text" class="form-control" placeholder="Username" />
                      </div>

                      <div class="input-group input-group-sm">
                        <span class="input-group-text">@</span>
                        <input type="text" class="form-control" placeholder="Username" />
                      </div>
                    </div>
                  </div>
                </div>
                <!-- Checkbox and radio addons -->
                <div c