Card in an accordion card

I have a dynamic list of pages I'm trying to display as cards within an accordion. The cards themselves work fine - except for a feint line at the bottom of each card, which extends across the page.

The code of the accordion card is below

<!-- Accordion card -->

<!-- Card header -->
<div class="card-header" role="tab" id="headingThree3">
  <a class="collapsed" data-toggle="collapse" data-parent="#accordionEx" href="#collapseThree3"
    aria-expanded="false" aria-controls="collapseThree3">
    <h3 class="mb-0 text-secondary">
      Members-Only pages <i class="fas fa-angle-down rotate-icon"></i>
    </h3>
  </a>
</div>

<!-- Card body -->
<div id="collapseThree3" class="collapse" role="tabpanel" aria-labelledby="headingThree3"
  data-parent="#accordionEx">
  <div class="card-body">
              <div class="row">

          <!-- Card -->

                        <div class="card col-md-4 mb-2">
              <!-- Card image -->
              <div class="view overlay">
                <img class="card-img-top" src="../../../resources/201/mainpics/thumbs300/liverpool-albert-dock-293.jpg" alt="">                                     </div>
              <!-- Card content -->
              <div class="card-body blue lighten-5">
                <!-- Title -->
                <h4 class="card-title purple-text">4th page, just to test</h4>
                <!-- Text -->
                <p class="card-text">Jut to test how the display looks on the new members home page. The main picture doesn't have adescription, so the page will fail W3C validation - a well as missing out on search engine opportunities.</p>
                <!-- Link -->
                <a href="../../../websites-for-trf/4378/fourth-test.html" class="btn btn-primary btn-sm float-right"><i class="fas fa-angle-double-right"></i></a>
                </div>
              </div>
                            <div class="card col-md-4 mb-2">
              <!-- Card image -->
              <div class="view overlay">
                                    <img class="card-img-top" src="../../../images/new-no-main-pic-blue.jpg" alt="test mo page">                    </div>
              <!-- Card content -->
              <div class="card-body blue lighten-5">
                <!-- Title -->
                <h4 class="card-title purple-text">test mo page</h4>
                <!-- Text -->
                <p class="card-text">mhbjh</p>
                <!-- Link -->
                <a href="../../../websites-for-trf/4356/mo.html" class="btn btn-primary btn-sm float-right"><i class="fas fa-angle-double-right"></i></a>
                </div>
              </div>
                            <div class="card col-md-4 mb-2">
              <!-- Card image -->
              <div class="view overlay">
                <img class="card-img-top" src="../../../resources/201/mainpics/thumbs300/Murcia-54.jpg" alt="">                                     </div>
              <!-- Card content -->
              <div class="card-body blue lighten-5">
                <!-- Title -->
                <h4 class="card-title purple-text">another test</h4>
                <!-- Text -->
                <p class="card-text">text entered here is very important, as it helps Google and other search engines. Make sure you fill this with lots of search terms.</p>
                <!-- Link -->
                <a href="../../../websites-for-trf/4376/another-test-mo.html" class="btn btn-primary btn-sm float-right"><i class="fas fa-angle-double-right"></i></a>
                </div>
              </div>
                            <div class="card col-md-4 mb-2">
              <!-- Card image -->
              <div class="view overlay">
                <img class="card-img-top" src="../../../resources/201/mainpics/thumbs300/Greenfield-188.jpg" alt="">                                        </div>
              <!-- Card content -->
              <div class="card-body blue lighten-5">
                <!-- Title -->
                <h4 class="card-title purple-text">yet another test</h4>
                <!-- Text -->
                <p class="card-text">This is the brief description field. Don't be tempted to just put a space instead of text!</p>
                <!-- Link -->
                <a href="../../../websites-for-trf/4377/yet-another-test.html" class="btn btn-primary btn-sm float-right"><i class="fas fa-angle-double-right"></i></a>
                </div>
              </div>
            <!-- Card -->
      </div>      
  </div>
</div>

many thanks Chris