.attention{
	position:relative;
	display:inline-block;
	font-size:0;
}
.attention:after{
	content:"";
	position:absolute;
	width:100%;
	height:100%;
	left:0;
	top:0;
	box-sizing:border-box;
	border:3px solid red;
	border-radius:4px;
	transform-origin:center;
	animation:att 0.6s linear 0s infinite normal;
}
@keyframes att {
	0%   {transform:scale(1)   ;opacity:0.9}
	100% {transform:scale(1.1,1.3) ;opacity:0}
}