<div class="parent">
  <div class="aspectratio aspectratio__min" data-type="min(50%, 200px)">4:3</div>
</div>

<div class="parent">
  <div class="aspectratio aspectratio__max" data-type="max(50%, 200px)">4:3</div>
</div>

<div class="parent">
  <div class="aspectratio aspectratio__clamp" data-type="clamp(200px, 50%, 400px)">4:3</div>
</div>

@import url("https://fonts.googleapis.com/css2?family=Exo:wght@600&display=swap");

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  width: 100vw;
  min-height: 100vh;
  font-family: "Exo", Arial, sans-serif;
  background-color: #222;
  color: #fff;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  font-size: 1.5rem;
  gap: 10px;
  padding: 10px;
}

.parent {
  font-size: 16px;
  line-height: 1.5;
  border: 1px dotted #f36;
  padding: 4px;
  position: relative;
}

.aspectratio {
  aspect-ratio: 4 / 3;
  background-color: #09f;
  display: flex;
  justify-content: center;
  align-items: center;
}

.aspectratio__min {
  width: min(50%, 200px);
}

.aspectratio__max {
  width: max(50%, 200px);
}

.aspectratio__clamp {
  width: clamp(200px, 50%, 400px);
}

.aspectratio::after {
  content: "width:" attr(data-type);
  position: absolute;
  left: 0;
  right: 0;
  white-space: nowrap;
  bottom: 5px;
  text-align: center;
}