header{                             /*标题栏*/
	font-family:"黑体","Noto Sans CJK SC";
	font-size:20px;            /*文字大小为20px*/
	display:flex;                  /**/
	justify-content:center; /**/
	align-items:center;      /*文字居中*/
	color:white;                  /*文字颜色为白色*/
	background:black;     /*背景颜色为黑色*/
	height:80px;             /*高度为80px*/  
	width:auto;             /*宽度自动调整*/
	border-radius:5px; /*5px的圆角*/
}
#dhl{
	display:flex;
}
#dhl td{
border:0px solid;
}
table{
	margin: 0 auto;
	text-align:center;
	border-collapse: collapse;
	border:2px solid;
}
th,td{
	border:1px solid;
}
footer{
	background:black;
	color:white;
	width:auto;
	height:100px;
	display:flex;
	justify-content:center;
	align-items:center;
	margin-left:auto;
	margin-right:auto;
	font-weight:bolder;
	border-radius:5px;
}