button:active{transform:translate(0px,1px)}
a:link {color:rgb(27, 0, 100);}     /* 未访问链接*/
a:visited {color:#b000c0;}  /* 已访问链接 */
a:hover {color:#ffb3e8;}  /* 鼠标移动到链接上 */
a:active {color:#d80090;}  /* 鼠标点击时 */
/*no under line*/
a:link {text-decoration:none;}
a:visited {text-decoration:none;}
a:hover {text-decoration:none;}
a:active {text-decoration:none;}
/*提示消息*/
.tooltip {
    position: relative;
    display: inline-block;
    border-bottom: 1px dotted black;
}
.tooltip .tooltiptext {
    visibility: hidden;
    width: 400px;
    background-color: rgba(0, 0, 0,.5);
    color: #fff;
    text-align: center;
    border-radius: 6px;
    padding: 5px 0;
/*消息定位 */
    position: absolute;
    z-index: 1;
    top: 100%;
    left: 50%;
    margin-left: -60px;
}
.tooltip:hover .tooltiptext {
    visibility: visible;
}