function focused() {

    let allDivElements = document.querySelectorAll('div div');

    allDivElements = Array.from(allDivElements);

    allDivElements.forEach(el => {

        el.addEventListener('mouseover', (e) => {

            e.currentTarget.classList = 'focused';

        });

        el.addEventListener('mouseleave', (e) => {

            e.currentTarget.classList.remove('focused');

        });

    });

}