genuary day 15 + day 28
for (let i = 0; i < 100; i++) {
let d = document.createElement('div');
d.className = 'btn';
let s = Math.abs((Math.random() * 20 - 10) + (Math.random() * 20 - 10) + 40);
d.style.cssText = `--size:${s}px;width:${s}px;height:${s}px;left:${Math.random()*90}vw;top:${Math.random()*90}vh;animation-delay:${-Math.random()*20}s,${-Math.random()*10}s;animation-duration:${15+Math.random()*10}s,${8+Math.random()*4}s`;
document.body.appendChild(d);
}