是它的左边界在中线还是右边界在中线啊
width: 200px;
height: 200px;
background-color: cyan;
position: absolute;
left: 50%;
}
是它的左边界在中线还是右边界在中线啊
width: 200px;
height: 200px;
background-color: cyan;
position: absolute;
left: 50%;
}