/* ------------------------------------------
 * IT书包
 * 网址：www.itshubao.com
 * 整理：yinq<3331653644@qq.com> 
 -------------------------------------------- */
body {
	display: flex;
	justify-content: center;
	align-items: center;
	background: #CCC;
	min-height: 100vh;
	margin: 0;
}
input[type="radio"] {
	display: none;
}
input[type="radio"]:checked + label {
	border-color: #009688;
}
input[type="radio"]:checked + label:after {
	transform: scale(0.7);
	background: #009688;
}
label {
	display: block;
	box-sizing: border-box;
	width: 120px;
	height: 120px;
	background: #CCC;
	margin: 120px;
	border: 12px solid #7A7A7A;
	border-radius: 50%;
	position: relative;
	cursor: pointer;
	transition: .2s;
}
label:before {
	content: '';
	position: absolute;
	display: block;
	height: 300%;
	width: 300%;
	top: -100%;
	left: -100%;
	z-index: -1;
	border-radius: 50%;
	transition: .3s;
}
label:after {
	content: '';
	display: block;
	height: 100%;
	width: 100%;
	background: #009688;
	border-radius: 50%;
	background-size: contain;
	transform: scale(0);
	transition: .2s;
}
label:active:before {
	background: #bfbfbf;
}