空HR
border:solid 1px red;
height:0px; border-top:dotted 1px red;
height:0px; border-top:dashed 1px red;
height:1px;
height:0px;
height:0px; border:solid 10px red;
height:0px; border-top:solid 10px red;
height:20px;
height:20px; border:solid 1px red;
height:1px; border-top:solid 1px red; border-bottom:solid 3px blue;