Add a gradient sky layer to a map | Mapbox GL JS

Add a customizable, gradient sky layer.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Add a gradient sky layer to a map</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
<link href="https://api.mapbox.com/mapbox-gl-js/v2.1.1/mapbox-gl.css" rel="stylesheet">
<script src="https://api.mapbox.com/mapbox-gl-js/v2.1.1/mapbox-gl.js"></script>
<style>
body { margin: 0; padding: 0; }
#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<div id="map"></div>
 
<script>
	// TO MAKE THE MAP APPEAR YOU MUST
	// ADD YOUR ACCESS TOKEN FROM
	// https://account.mapbox.com
	mapboxgl.accessToken = '<your access token here>';
var map = new mapboxgl.Map({
container: 'map',
zoom: 14.77,
center: [127.60597, 35.67283],
pitch: 83,
style: 'mapbox://styles/mapbox-map-design/ckhqrf2tz0dt119ny6azh975y'
});
 
map.on('load', function () {
map.addSource('mapbox-dem', {
'type': 'raster-dem',
'url': 'mapbox://mapbox.mapbox-terrain-dem-v1',
'tileSize': 512,
'maxzoom': 14
});
map.setTerrain({ 'source': 'mapbox-dem', 'exaggeration': 1.5 });
 
map.addLayer({
'id': 'sky',
'type': 'sky',
'paint': {
// set up the sky layer to use a color gradient
'sky-type': 'gradient',
// the sky will be lightest in the center and get darker moving radially outward
// this simulates the look of the sun just below the horizon
'sky-gradient': [
'interpolate',
['linear'],
['sky-radial-progress'],
0.8,
'rgba(135, 206, 235, 1.0)',
1,
'rgba(0,0,0,0.1)'
],
'sky-gradient-center': [0, 0],
'sky-gradient-radius': 90,
'sky-opacity': [
'interpolate',
['exponential', 0.1],
['zoom'],
5,
0,
22,
1
]
}
});
});
</script>
 
</body>
</html>