body{
-webkit-tap-highlight-color:rgba(0,0,0,0);
}
[href]:active,
button:active,
[type=reset]:active,
[type=button]:active,
[type= submit]:active{
background-image:linear-gradient(rgba(0,0,0,.05),rgba(0,0,0,.05));
}
[href] img:active{
outline:999px solid rgba(0,0,0,.05);
outline-offset:-999px;
-webkit-clip-path:polygon(0 0 ,100% 0,100% 100%,0 100%);
clip-path:polygon(0 0 ,100% 0,100% 100%,0 100%);
}
outline-offset 从edge15才开始被支持
