looking up

let c, clouds, nClouds;
function setup() {
  clouds = [];
  nClouds = int(random(5, 20));
  c = min(min(windowWidth, windowHeight) * 0.9, 800);
  cnv = createCanvas(c, c);
  angleMode(DEGREES);
  r1 = random(250, 300);
  g1 = random(250, 300);
  b1 = random(250, 300);
  noStroke();
  for (let i = 0; i < nClouds; i++) {
    clouds.push(new Cloud());
  }
}
function draw() {
  translate(width / 2, height / 2);
  for (let i = c * 2; i > 0; i--) {
    fill(r1 - i / 3, g1 - i / 3, b1 - i / 3);
    circle(0, 0, i);
  }
  for (let i = 0; i < clouds.length; i++) {
    push();
    translate(clouds[i].x, clouds[i].y);
    clouds[i].display();
    clouds[i].move();
    pop();
  }
}

class Cloud {
  constructor() {
    this.x = random(-c, c);
    this.y = random(-c / 2, c / 2);
    this.pos = [];
    this.cSize = [];
    for (let i = 0; i < 500; i++) {
      let x = random(-c / 3, c / 3);
      let y = randomGaussian(5, 10);
      this.pos[i] = createVector(x, y);
      this.cSize[i] = random(0, (c / 3 - abs(x)) / 2);
    }
    this.delta = random(0.01, 1);
  }
  display() {
    for (let i = 0; i < this.pos.length; i++) {
      fill(r1 / 3, g1 / 3, b1 / 3, 3 + 2 * abs(sin(this.y)));
      circle(this.pos[i].x, this.pos[i].y, this.cSize[i]);
    }
  }
  move() {
    if (this.x > -c * 2) {
      this.x -= this.delta;
    } else {
      this.x = c * 2;
    }
  }
}

function mousePressed() {
  setup();
  draw();
}