边框在CSS上的排列不正确
body{
margin: 0;
padding: 0;
background-color: #073146;
}
.box{
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%,-50%);
width: 350px;
height: 180px;
background-color: #001e2d;
box-sizing: borde...