<main>

  <section>
    <!-- Aspect ratio padding trick -->
    <figure class="img-4-3">
      <img data-twic-src="placeholder:auto">
    </figure>
  </section>

</main>

main {
  max-width: 1000px;
  margin: auto;
  padding: 1em;
}

section {
  display: flex;
  justify-content: center;
  margin-bottom: 1em;
}

img {
  display: block;
}

figure {
  margin: 0;
}

.img-4-3 {
  position: relative;
  width: 100%;
  height: 0;
  padding-top: calc(3 / 4 * 100%);
}

.img-4-3 > img {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  object-fit: cover;
}