实现流程:
div => 内容缩小,边框加粗 => 内容缩小为0 =>把下边框去掉,剩下上,左,右边框 => 设置左右边框为透明
.className::after{
content:'';
border-top: 9px solid white;
border-left: 12px solid transparent;
border-right: 12px solid transparent;
}
实现流程:
div => 内容缩小,边框加粗 => 内容缩小为0 =>把下边框去掉,剩下上,左,右边框 => 设置左右边框为透明
.className::after{
content:'';
border-top: 9px solid white;
border-left: 12px solid transparent;
border-right: 12px solid transparent;
}