* { box-sizing: border-box; }

body {
  background-image: radial-gradient(
      50% 50% at center top,
      rgba(0, 0, 0, 0.66),
      rgb(38, 38, 38)
    ),
    linear-gradient(rgb(255, 255, 255), rgb(38, 38, 38));
  color: hsl(0 0% 100%);
  display: grid;
  font-family: Montserrat, sans-serif;
  font-size: 200%;
  font-weight: 800;
  height: 100vh;
  margin: 0;
  padding: 1.5rem;
  place-items: center;
  text-align: center;
  text-shadow: 0 1px 1px hsl(0 0% 0%);
  max-width: 100%;
}

.parent {
  background: hsl(0 0% 30%);
  border: 5px solid hsl(0 0% 0%);
  container: parent / inline-size;
  display: grid;
  padding: 1.5rem;
  place-items: center;
  width: min(100%, 80ch);
}

.child {
  background-color: #ff7a18;
  border: 5px solid hsl(0 0% 0%);
  padding: 1.5rem;
  position: relative;
  width: 100cqi;
  
  &::before {
    content: "I'm Orange";
    inset: 3px 0;
    position: absolute;
  }
}

@container parent (width > 30ch) {
  .child {
    background: linear-gradient(
      130deg,
      #ff7a18,
      #af002d 41.07%,
      #319197 76.05%
    );
    width: 50cqi;
    
    &::before {
      content: "I'm a rainbow!";
    }
  }
}