p{
            width: 50px;
            height: 40px;
            line-height: 40px; # 设置盒子宽高
        }
        p:nth-child(1){
            border-top-style: solid; # 设置上边框的样式
            border-top-width: 1px;
            border-top-color: red;
        }
        p:nth-child(2){
            border-right-style:solid; # 右边框的样式
            border-right-width:33px;
            border-right-color:aquamarine;
        }
        p:nth-child(3){
            border-bottom-style:solid; # 下
            border-bottom-width:22px;
            border-bottom-color:blue;
        }
        p:nth-child(4){ # 四条边的样式
            border-color:aliceblue saddlebrown darkblue gainsboro; # 颜色
            border-width:1px 1px 4px 2px; # 宽度
            border-style:solid dashed dotted double; 
                        # ↑实线 ↑虚线 ↑点线     ↑双线
        }
        
        p:nth-child(1){
            border:double 3px gainsboro; # 复合设置
        }
        p:nth-child(2){
            border:solid 2px cadetblue;
        }
        p:nth-child(3){
            border-right:dashed 3px cadetblue; # 设置右边框样式
            border-left:double 2px darkblue;
        }
        p:nth-child(4){
            border-right:dotted 5px firebrick;
            
        }
        p:nth-child(5){
            border-left:double 1px lavender;
        }