<div style="--size: circle"></div>
<div style="--size: ellipse"></div>
<div style="--size: circle at left center closest-side"></div>
<div style="--size: circle at left center closest-corner"></div>
<div style="--size: ellipse at left center closest-side"></div>
<div style="--size: ellipse at left center closest-corner"></div>
<div style="--size: circle 0"></div>
<div style="--size: ellipse 0px 50px"></div>
<div style="--size: ellipse 50% 0"></div>
<div style="--size: 0"></div>
<div style="--size: 0 1px"></div>
<div style="--size: 1px 100px"></div>
<div style="--size: 1px 100%"></div>
<div style="--size: 100% 1px"></div>
<div style="--size: 0 100%"></div>
<div style="--size: 100% 0"></div>
<div style="--size: .5px 50%"></div>
<div style="--size: 50% .5px"></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;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  padding: 10px 10px 30px;
  gap: 30px 10px;
  font-family: "Exo", Arial, sans-serif;
  background-color: #222;
  color: #fff;
  place-content: center;
}

:root {
  --cyanHSL: hsl(180 100% 50%);
  --pinkHSL: hsl(328 100% 54%);
}

div {
  border-radius: 5px;
  border: 1px solid #efefef;
  min-height: 40vh;
  position: relative;
  background-image: radial-gradient(
    var(--size),
    var(--cyanHSL),
    var(--pinkHSL)
  );
}

div::after {
  content: attr(style);
  position: absolute;
  top: calc(100% + 5px);
  white-space: nowrap;
  left: 50%;
  transform: translate(-50%, 0);
  font-size: 12px;
}

External CSS

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External JavaScript

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