<div id="bgElem">
</div>

#bgElem {
  display: flex;
  flex-wrap: wrap;
}
.card {
  width: 2.5em;
  text-align: center;
  border: 1px solid #CCC;
  margin: .5em;
  background-color: #FAFEEE;
  border-radius: 5px;
  box-shadow: 0 5px 5px #eee;
}

const element = document.createElement('div');
element.classList.add('card');
const p = document.createElement('p');
p.innerText = 'QnA';
element.appendChild(p);
const hr = document.createElement('hr');
element.appendChild(hr);

const backgroundSection = document.getElementById('bgElem');
for (let i = 0; i < 45; i++) {
  backgroundSection.appendChild(element.cloneNode(true));
}