var shadowTexts = $('.cursor-shadow'),
    arrayLetters;
$.each(shadowTexts, function () {
    var i = 0;
    if (this.innerHTML !== undefined) {
        arrayLetters = this.innerHTML.split('');
        for (i = 0; i < arrayLetters.length; i++) {
            arrayLetters[i] = '<span>' + arrayLetters[i] + '</span>';
        }
        this.innerHTML = arrayLetters.join('');
        arrayLetters = $(this).find('span');
    }
});

function handleMouseMove(e) {
    $(arrayLetters).each(function () {
        var shadowStepY = ($(this).offset().top - e.y) / 300,
            shadowStepX = ($(this).offset().left - e.x) / 300,
            fullTextShadow = '0px 0px 0px #000',
            i = 1;
        for (i = 1; i < 20; i += 2) {
            fullTextShadow += ', ' + (shadowStepX * i) + 'px ' + (shadowStepY * i) + 'px 1px rgba(10,10,10,' + (3 / i) + ')';
        }
        $(this).css({
            'text-shadow': fullTextShadow
        });
    });
}
document.onmousemove = handleMouseMove;