varia-library-website/library/static/js/script.js

// Cloud section ===================== old school code divider =================
function rn(from, to) {
  return ~~(Math.random() * (to - from + 1)) + from;
}

function rs() {
  return arguments[rn(1, arguments.length) - 1];
}

function boxShadows(max) {
  let ret = [];
  for (let i = 0; i < max; ++i) {
    ret.push(`
      ${ rn(1, 110) }vw ${ rn(1, 110) }vh ${ rn(20, 30) }vmin ${ rn(10, 60) }vmin
      ${ rs('#F52D75', '#CCBD4F', '#32497F', '#EB4377') }
    `)
  }
  return ret.join(',');
}

const cloud = document.querySelector('#cloud');

function update() {
  if (window.screen.availWidth > 400 && window.screen.availHeight > 400 ) {
    cloud.style.boxShadow = boxShadows(30);
  }
  else {
    document.body.style.backgroundImage = "linear-gradient(to bottom right, white, #F52D75)";
  }
}

window.addEventListener('load', update);