gistfile1.txt

function fadehover(el){
  el.onmouseover = function(){
    el.Q = []
    fx(el, 500, function(amt, el){
      el.style.background = "none";
      el.style.backgroundColor = "rgba(0,0,0,"+amt+")"
    })
  };
  el.onmouseout = function(){
    el.Q = []
    fx(el, 300, function(amt, el){
      el.style.background = "none";
      el.style.backgroundColor = "rgba(0,0,0,"+(1-amt)+")"
    })
  }
}

function fx(element, duration, callback){
  var amount,
    begin = +new Date, 
    loop;
  if(element.R)
    return element.Q=(element.Q||[]).concat([arguments]); 
  element.R = 1;
  (loop = function(){ //set the main looper
    if(
    callback(
      (1-Math.cos(
        (amount = (new Date-begin)/duration)
      *Math.PI))/2,
      element
    ) != 9 //9 terminates execution
    && amount<1 && element.R) setTimeout(loop, 10); else{
      !(amount%1)||callback(1,element);
      element.R = 0;
      element.Q && element.Q.length &&
        fx.apply(this, element.Q.shift());
    }
  })()
}

  if(document.querySelectorAll){
    var els = document.querySelectorAll(".menu ul li a")
    for(var i = 0; i < els.length; i++){
      fadehover(els[i]);
    }
  }