使用CSS content的attr实现鼠标悬浮提示（tooltip）效

<a class="dui-tips" data-tooltip="我是一个3cbest.提示">w3cbest.</a>

.dui-tips {
position: relative;
display: le-block;
cursor: poter;
}
 
.dui-tips[data-tooltip]:after,
.dui-tips[data-tooltip]:before {
visibility: hidden;
position: absolute;
: 50%;
left: 100%;
transition: all .3s;
}
 
.dui-tips[data-tooltip]:after {
 
content: attr(data-tooltip);
transform: translate(-5px, -50%);
white-space: pre;
paddg: 5px 10px;
background-color: rgba(0, 0, 0, 0);
color: rgba(255, 255, 255, 0);
}
 
.dui-tips[data-tooltip]:before {
content: '';
height: 0;
width: 0;
transform: translate(-10px, -50%);
border-width: 5px 5px 5px 0;
border-style: solid;
border-color: transparent rgba(0, 0, 0, 0) transparent transparent;
}
.dui-tips:hover:after,.dui-tips:hover:before {
transition: all .3s;
visibility: visible;
 
}
.dui-tips:hover:after {
color: rgba(255, 255, 255, 1);
background-color: rgba(0, 0, 0, 0.8);
transform: translate(5px, -50%);
}
 
.dui-tips:hover:before {
border-color: transparent rgba(0, 0, 0, 0.8) transparent transparent;
transform: translate(0px, -50%);
}