*{
    margin: 0;
    padding: 0;
}
.triangle_border_up{
    width:0;
    height:0;
    border-width:0 6px 6px;
    border-style:solid;
    border-color:transparent transparent #393939;/*透明 透明  灰*/
    position:relative;
}
i,ul,li{
    font-style: normal;
    list-style:none ;
}
a{
    text-decoration:none;
}