Bootstrap CSS class .row-cols-md-1

    <div class="container">
        <div class="row row-cols-md-1">
        <div class="col">Column 1</div>
        <div class="col">Column 2</div>
        <div class="col">Column 3</div>
        <div class="col">Column 4</div>
        <div class="col">Column 5</div>
        <div class="col">Column 6</div>
        </div>
    </div>