snowfall-animation.css

@-webkit-keyframes snowfall {
            	0% {
              		top: -40px;
            	}
                25% {
                	top: 250px;
                    left: 100px;
                }
                50% {
                	top: 500px;
                    left: -100px;
                }
            	100% {
              		top: 1000px;
                    left: 0px;
            	}
        	}