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Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

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Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

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HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

  height 100%
  margin 0
  background-color #0
  transition background-color .5s
  width 100%
  height 100%
  vertical-align top
  fill blue
  // stroke white
  stroke-width 5
  stroke-dasharray 20
  transition fill .5s
  cursor pointer
              function create(type){
  return document.createElementNS("", type)
let w // wiewport width
let h // wiewport height
let diag // diagonal
let time = 0 // time from script beginning
const init =
const svg = create("svg")
let count = 5
function createCircle(cx,cy,r){
  return ` M ${cx} ${cy}
    m ${-r}, 0
    a ${r},${r} 0 1,1 ${r * 2},0
    a ${r},${r} 0 1,1 ${-r * 2},0 `

const path = create('path')
path.setAttribute('fill-rule', 'evenodd')

const radius = 100
const min = .2
function draw() {
  const circles = []
  for(let i = 0; i < count; i++) {
    const ii = i / count + time / count * 2/3
    const ang = ii * Math.PI * 2
    const cos = Math.cos(ang)
    const sin = Math.sin(ang)
    const c = 1/Math.tan(ang / 2)
    const x = cos * radius
    const y = sin * radius
    circles.push([w/2 + x, h / 2 + y + 30 * c, 30 * c])
  if(Math.floor(time * 2/3) % 2)
   circles.push([w/2, h / 2, diag / 2])
  path.setAttribute("d", => createCircle(...c)).join(' '))
  const r = -time * 70
  path.setAttribute('transform', `rotate(${r}, ${w/2}, ${h/2})`)

function loop() {
  time = ( - init) / 1000

function resize() {
  w = window.innerWidth
  h = window.innerHeight
  diag = Math.hypot(w, h)

window.addEventListener('wheel', e => {
  count = Math.max(1, count + Math.sign(e.deltaY))
path.addEventListener('click', (e) => {
  e.stopPropagation() = `hsl(${Math.random()*360},100%,${Math.random()*20+30}%)`
path.dispatchEvent(new Event('click'))
document.body.addEventListener('click', (e) => {
  e.stopPropagation() = `hsl(${Math.random()*360},100%,${Math.random()*20}%)`
window.addEventListener('resize', resize)
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