body{        width:100%;        background-color:#AAAAAA;           text-align: center;        }a{   text-decoration:none;/*【清除链接的下划线】*/ } p{     text-align:left;     text-indent:2em; } hr{ 	width:75%; 	color:#AAAAAA; } nav{     height:135px;     background-color:#FFFFFF;     width:1200px;     display: inline-block;     /*background-image:url(image/santa-clarita-fire-1200.jpg);*/ } 	nav ul li{ 		float:left; 		display:inline; 		margin-right:10px; 		 	} 	nav ul li a{ 		color:#0000FF; 	} .maincontent{     width:1200px;     background-color:#EEEEFF;     display: inline-block; }.left-content{ 	float:left; 	width:200px;  	} 	.left-content p{ 		text-indent:0; 	} .mid-content{ 	float:left;     width:790px;     /* background-color: #FF0000; */     margin-top:10px;     margin-bottom:10px;     /*box-shadow:0 10px 20px 0 rgba(0,0,40,0.6);*/ 	} 	.mid-content header{  	} 	.video-article{ 		margin-bottom:10px; 		background-color:#FFFFFF;   		border-style:solid; 		border-width:2px; 		border-color:#00AA00; 		} 	.edu-article{ 		padding:10px; 		/* background-color:#EEcc66; */ 		background-color:#cccc88;   		border-style:solid; 		border-width:2px; 		border-color:#00AA00; 	} 	.edu-article header{	 		height:30px; 		background-color:#FFFFFF; 		background-image: linear-gradient(180deg, #FFFF00, #44AA44 ,#FFFF00); 		text-align:left; 		box-shadow: 0px 0px 15px 0px #AAAAFF inset; 		 	} 	/* .edu-article header h4{ 		margin:5px; 		display:inline-block; 	} */ 	.edu-article header span{ 	 	/* float:right;  */	font-size:14px; 	color:#0000FF; 	text-decoration:underline; 	text-align:right; 	} 	/* .edu-article header h4{	 		 		margin:12px; 		 	} */ 	.step{	 		margin-bottom:20px; 		padding:10px; 		background-color:#AAAA88; 		/* border: 2px solid #888844; */ 		/* border-radius:3px; */ 		/* box-shadow: 0px 0px 5px 0px #AAAACC inset;  */ 	} 	.step h3{ 		text-align:left; 		padding-left:40px; 	}  .right-content{ 	float:left; 	width:200px; }  .sidebar{ 	overflow:hidden;     margin:10px;     border-style:solid;     border-width:2px;     border-color:#00AA00;     background-color:#FFFFFF; }  	.sidebar ul{ 		margin:0px; 		padding:0px; 		list-style: none; 	} 	.sidebar ul li{ 		width:100%; 		background-color:#EEEEEE; 		text-align:center; 	}  	.sidebar ul li a{ 		text-decoration:none; 		background-color:#FFFFFF; 		width:100%; 		margin:0px; 		padding:0px; 		overflow: hidden; 		text-overflow: ellipsis; 		white-space: nowrap; 	} .list ul{     margin:0px;     padding:40px 0;     list-style: none; }  	.list ul li{ 		width:100%; 		background-color:#EEEEEE; 		text-align:left; 	}  .article{ 	width:740px; 	margin:20px; } 	.article header{ 		 /*background:url(image/gradient.jpg); 		background-repeat:repeat-x; 		background-size:100% 200%; 		background-color:#eeeeff; 		box-shadow:0 10px 20px 0 rgba(0,0,116,0.6); 		padding:1px;*/ 		margin-bottom:20px; 		 	} 	.annotation{ 		text-align:left; 		color:#FF0000; 		text-indent:2em;		 	}  .software ol{ 	 	margin-left:200px; 		color:#0000FF; 	text-align:left; }	  	.software a{ 		color:#0000FF; 		text-decoration:underline; 	}  .related{ 	text-align:left; 	width:600; } .footer{ 	padding-top:10px;     width:1200px; 	height:35px; 	display: inline-block;     text-align:center;     background-color:#FFFFFF; } .imagearea ul li img{width:auto;height:100px;background-color:#000080;border-radius:5px;} .imagearea{positon:relative;} .imagearea ul li{display:inline;} .imagearea ul li img:hover{position:absolute;width:auto;height:auto;background-color:#FF0000;border-radius:5px;padding:4px;}