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CSS

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JavaScript

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Babel includes JSX processing.

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HTML 

              
                <div></div>
!

CSS 

              
                
body {
	margin: 0;
	padding: 0;
	height: 100vh;
	overflow: hidden;
	--sz: 5px; /*** size ***/
	--sp: 10s; /*** speed ***/
	--b1: #3c3532;
	--b2: #1c1b18;
	--b3: #0c0b0a;
	--b4: #0c0b0ae0;
	--c1: #e399ff;
	--ts: 50%/calc(var(--sz) * 17.5) calc(var(--sz) * 29.5);
}

div {
	height: 100vh;
	background:
		/* black shadows */
		radial-gradient(circle at 50% 50%, var(--b4) calc(var(--sz) * 1), #fff0 calc(var(--sz) * 8)) var(--ts),
		radial-gradient(circle at 0% 0%, var(--b4) calc(var(--sz) * 1), #fff0 calc(var(--sz) * 8)) var(--ts),
		radial-gradient(circle at 0% 100%, var(--b4) calc(var(--sz) * 1), #fff0 calc(var(--sz) * 8)) var(--ts),
		radial-gradient(circle at 100% 0%, var(--b4) calc(var(--sz) * 1), #fff0 calc(var(--sz) * 8)) var(--ts),
		radial-gradient(circle at 100% 100%, var(--b4) calc(var(--sz) * 1), #fff0 calc(var(--sz) * 8)) var(--ts),
		/* border bottom */
		conic-gradient(from 90deg at 97.5% 67%, var(--c1) 0 87.5deg, #fff0 88deg 100%) var(--ts), /*repeated*/
		conic-gradient(from 90deg at 97.5% 67%, var(--c1) 0 87.5deg, #fff0 88deg 100%) var(--ts),
		conic-gradient(from 182.5deg at 2.5% 67%, #fff0 0 0deg, var(--c1) 0.5deg 90deg, #fff0 0 100%) var(--ts), /*repeated*/
		conic-gradient(from 182.5deg at 2.5% 67%, #fff0 0 0deg, var(--c1) 0.5deg 90deg, #fff0 0 100%) var(--ts), 
		/* border top */
		conic-gradient(from 270deg at 2.5% 33%, var(--c1) 0 87.5deg, #fff0 88deg 100%) var(--ts), /*repeated*/
		conic-gradient(from 270deg at 2.5% 33%, var(--c1) 0 87.5deg, #fff0 88deg 100%) var(--ts),
		conic-gradient(from 2.5deg at 97.5% 33%, #fff0 0 0deg, var(--c1) 0.5deg 90deg, #fff0 0 100%) var(--ts), /*repeated*/
		conic-gradient(from 2.5deg at 97.5% 33%, #fff0 0 0deg, var(--c1) 0.5deg 90deg, #fff0 0 100%) var(--ts),
		/* bottom */
		conic-gradient(from 116.5deg at 50% 85.5%, var(--b1) 0 127deg, #fff0 0 100%) var(--ts), /*repeated*/
		conic-gradient(from 116.5deg at 50% 85.5%, var(--b1) 0 127deg, #fff0 0 100%) var(--ts), /*repeated*/
		conic-gradient(from 116.5deg at 50% 85.5%, var(--b1) 0 127deg, #fff0 0 100%) var(--ts),
		conic-gradient(from 120deg at 50% 83%, var(--c1) 0 120deg, #fff0 0 100%) var(--ts),
		/* top */
		conic-gradient(from -63.5deg at 50% 14.5%, var(--b1) 0 127deg, #fff0 0 100%) var(--ts), /*repeated*/
		conic-gradient(from -63.5deg at 50% 14.5%, var(--b1) 0 127deg, #fff0 0 100%) var(--ts), /*repeated*/
		conic-gradient(from -63.5deg at 50% 14.5%, var(--b1) 0 127deg, #fff0 0 100%) var(--ts),
		conic-gradient(from -60deg at 50% 17%, var(--c1) 0 120deg, #fff0 0 100%) var(--ts),
		/* central gradient */
		conic-gradient(
			from 0deg at 50% 50%, #fff0 0 2deg, 
			var(--b2) 2.5deg 57.5deg, 
			#fff0 58deg 62.5deg, 
			var(--b1) 63deg 117.5deg, 
			#fff0 118deg 122.5deg, 
			var(--b3) 123deg 177.5deg, 
			#fff0 178deg 182deg, 
			var(--b2) 182.5deg 237.5deg, 
			#fff0 0 242.5deg, 
			var(--b1) 243deg 297.5deg, 
			#fff0 298deg 302.5deg, 
			var(--b3) 303deg 357.5deg,
			#fff0 358deg 360deg
		) var(--ts),
		/* bg */
		var(--c1);
	animation: colors var(--sp) linear 0s infinite;
}

@keyframes colors {
	100% { filter: hue-rotate(360deg); }
}
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JS
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