#loading {
	margin:auto;
	height:100px;
	width:100px;
	border-radius:50px;
	margin-top:150px;
	color:white;
	text-align:center;
	line-height:100px;
	box-shadow:-25px -25px 1px rgba(40,200,255,0.6),-35px 0px 1px rgba(255,120,100,0.6),-25px 25px 1px rgba(255,80,150,0.6),0px 35px 1px rgba(150,80,139,0.6),25px 25px 1px rgba(156,110,245,0.6),25px -25px 1px rgba(93,124,228,0.6),0px -35px 1px rgba(112,130,255,0.6),35px 0px 1px rgba(141,109,200,0.6);
	transition:all 1s;
	animation:loading 1s ease-in-out infinite;
	animation-direction:alternate;
	-webkit-animation:loading 1s ease-in-out infinite;
	-webkit-animation-direction:alternate;
}
@keyframes loading {
	0% {
	box-shadow:-25px -25px 1px rgba(40,200,255,0.6),-35px 0px 1px rgba(255,120,100,0.6),-25px 25px 1px rgba(255,80,150,0.6),0px 35px 1px rgba(150,80,139,0.6),25px 25px 1px rgba(156,110,245,0.6),25px -25px 1px rgba(93,124,228,0.6),0px -35px 1px rgba(112,130,255,0.6),35px 0px 1px rgba(141,109,200,0.6);
	transform:rotate(0deg);
}
50% {
	box-shadow:-5px -5px 1px rgba(40,200,255,0.6),-7px 0px 1px rgba(255,120,100,0.6),-5px 5px 1px rgba(255,80,150,0.6),0px 7px 1px rgba(150,80,139,0.6),5px 5px 1px rgba(156,110,245,0.6),5px -5px 1px rgba(93,124,228,0.6),0px -7px 1px rgba(112,130,255,0.6),7px 0px 1px rgba(141,109,200,0.6);
	transform:rotate(360deg);
}
100% {
	box-shadow:-100px -100px 1px rgba(40,200,255,0.6),-140px 0px 1px rgba(255,120,100,0.6),-100px 100px 1px rgba(255,80,150,0.6),0px 140px 1px rgba(150,80,139,0.6),100px 100px 1px rgba(156,110,245,0.6),100px -100px 1px rgba(93,124,228,0.6),0px -140px 1px rgba(112,130,255,0.6),140px 0px 1px rgba(141,109,200,0.6);
	background-color:darkgray;
	transform:rotate(360deg);
}
@-webkit-keyframes loading {
	0% {
	box-shadow:-25px -25px 1px rgba(40,200,255,0.6),-35px 0px 1px rgba(255,120,100,0.6),-25px 25px 1px rgba(255,80,150,0.6),0px 35px 1px rgba(150,80,139,0.6),25px 25px 1px rgba(156,110,245,0.6),25px -25px 1px rgba(93,124,228,0.6),0px -35px 1px rgba(112,130,255,0.6),35px 0px 1px rgba(141,109,200,0.6);
	transform:rotate(0deg);
}
50% {
	box-shadow:-5px -5px 1px rgba(40,200,255,0.6),-7px 0px 1px rgba(255,120,100,0.6),-5px 5px 1px rgba(255,80,150,0.6),0px 7px 1px rgba(150,80,139,0.6),5px 5px 1px rgba(156,110,245,0.6),5px -5px 1px rgba(93,124,228,0.6),0px -7px 1px rgba(112,130,255,0.6),7px 0px 1px rgba(141,109,200,0.6);
	transform:rotate(360deg);
}
100% {
	box-shadow:-100px -100px 1px rgba(40,200,255,0.6),-140px 0px 1px rgba(255,120,100,0.6),-100px 100px 1px rgba(255,80,150,0.6),0px 140px 1px rgba(150,80,139,0.6),100px 100px 1px rgba(156,110,245,0.6),100px -100px 1px rgba(93,124,228,0.6),0px -140px 1px rgba(112,130,255,0.6),140px 0px 1px rgba(141,109,200,0.6);
	background-color:darkgray;
	transform:rotate(360deg);
}
}​

HTML

<div id="loading">
    加载中
</div>