​

​

Array.from(document.querySelectorAll('.grid div'),el => {

const randomNumber = (min, max) => Math.floor(Math.random() * (max - min + 1) + min);

const randomByte = () => randomNumber(0, 255)

const randomPercent = () => (randomNumber(5, 50) * 0.01).toFixed(2)

const randomCssRgba = () => `rgba(${[randomByte(), randomByte(), randomByte(), randomPercent()].join(',')})`

let c = randomCssRgba();

el.style.color=el.style.background = c;

  el.addEventListener("mouseover", function( event ) {   

    // highlight the mouseover target

    event.target.style.color = "red";

​

    // reset the color after a short delay

    setTimeout(function() {

      event.target.style.color = c;

    }, 5000);

  }, false);}

          );

​

​