/*定义一个动画*/
@keyframes box-ani{
	from{
		transform: rotateX( -10deg) rotateY(0deg);
		}
	to{
		transform: rotateX( -10deg) rotateY(360deg);
		}
	}
body {
	/*背景为黑色*/
		background-color: white;
		}

			/* #box相当于id="box" */
#box {
				/* 设置边框 */
		border: 2px solid black;
		height: 250px;
		width: 200px;
				/* 固定定位，以浏览器为标准进行定位 */
		position: fixed;
		left: calc(50% - 100px);
		top: calc(50% - 125px);
				/* 把盒子变成一个3D的盒子 */
		transform-style: preserve-3d;
		transform: rotateX(-10deg);
		/*使用定义好的动画*/
		animation-name: box-ani;
		animation-duration: 20s;
		animation-iteration-count: infinite;
		animation-timing-function: linear;
		animation-play-state: paused;		
	}

			/* id="box"下面的所有img标签 */
#box>img {
				width: 100%;
				height: 100%;
				/* 绝对定位，以父级为标准进行定位 */
				position: absolute;
				left: 0px;
				top: 0px;
				box-shadow: 0px 0px 20px 10px white;
				}
			/* 第一张图片 */
			#box>img:nth-child(1){
				transform: rotateY(30deg) translateZ(600px);
			}
			/* 第二张图片 */
			#box>img:nth-child(2){
				transform: rotateY(60deg) translateZ(600px);
			}
			#box>img:nth-child(3){
				transform: rotateY(90deg) translateZ(600px);
			}
			#box>img:nth-child(4){
				transform: rotateY(120deg) translateZ(600px);
			}
			#box>img:nth-child(5){
				transform: rotateY(150deg) translateZ(600px);
			}
			#box>img:nth-child(6){
				transform: rotateY(180deg) translateZ(600px);
			}
			#box>img:nth-child(7){
				transform: rotateY(210deg) translateZ(600px);
			}
			#box>img:nth-child(8){
				transform: rotateY(240deg) translateZ(600px);
			}
			#box>img:nth-child(9){
				transform: rotateY(270deg) translateZ(600px);
			}
			#box>img:nth-child(10){
				transform: rotateY(300deg) translateZ(600px);
			}
			#box>img:nth-child(11){
				transform: rotateY(330deg) translateZ(600px);
			}
			#box>img:nth-child(12){
				transform: rotateY(360deg) translateZ(600px);
	}