Bootstrap card not collapsing with other cards and merging with cards

Question

I'm using bootstrap to create a grid of cards, but all the cards are merging together when resizing the screen. This mainly happened when i tried to layout the icons to appear at the top left of the card and the bottom middle whilst adding a a href tag to the image.

<div class="col-sm-6 col-md mt-3">
  <div class="card" style="position: relative;">
      <a href="#" style="position: absolute; top: 0; left: 0; z-index: 2; width: 100%; height: 100%; pointer-events: none;">
          <img src="https://images.igdb.com/igdb/image/upload/t_cover_big/co7lbb.png" alt="" style="pointer-events: auto;">
      </a>
      <div class="icon-placeholder" style="position: absolute; top: 0; left: 0; z-index: 3;">
          <!-- Heart icon on top left -->
          <i id="heart" class="fas fa-heart heart-icon top-left-icon"></i>
          <!-- Other icons on bottom -->
          <div class="bottom-icons" style="position: absolute; bottom: -300px; left:100px;">
              <i class="fas fa-comment comment-icon p-2"></i>
              <i class="fas fa-share share-icon p-2"></i>
              <!-- ... add more icons as needed -->
          </div>
      </div>
  </div>

---- CSS stylesheet ----

  display: flex;
  justify-content: space-evenly;
  margin-top: auto; /* Push the bottom icons to the bottom */
} 


.icon-placeholder {
  position: absolute;
  top: 0;
  left: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 100%;
  height: 100%;
  padding: 10px;
  box-sizing: border-box;
}

.card img {
  border-radius: 20px;
  max-height: 320px;
  max-width: 320px;
  object-fit: cover;
  display: block;
}

    .card {
  position: relative;
  border-radius: 20px;
  background-color: #ffffff00;
  max-width: 264px;
  max-height: 352px;
  transition: transform .2s; /* Add transition property for smooth animation */
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
}