app/assets/javascripts/navigation_arrows.js
$(document).ready(function() {
var timer;
$(document).mousemove(function() {
if (timer) {
clearTimeout(timer);
timer = 0;
}
$(".left-arrow").fadeIn(1000);
$(".right-arrow").fadeIn(1000);
timer = setTimeout(function() {
$(".left-arrow").fadeOut(1000);
$(".right-arrow").fadeOut(1000);
}, 500)
});
});