给大家分享一个用CSS 3.0实现水滴单选框动画，效果如下：
以下是代码实现，欢迎大家复制、粘贴和收藏。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>CSS 3.0实现水滴单选框</title>
<style>
@import url(https://fonts.googleapis.com/css?family=Raleway:400);
@keyframes checkIn {
0% {
top: -1%;
height: 10px;
width: 24px;
margin-left: -12px;
}
7% {
top: -4%;
height: 12.5px;
width: 22px;
margin-left: -11px;
}
17% {
top: -2%;
height: 15px;
width: 12px;
margin-left: -6px;
}
25% {
top: 20%;
height: 15px;
width: 10px;
margin-left: -5px;
}
30% {
top: 102%;
height: 10px;
width: 28px;
margin-left: -14px;
}
45% {
top: 50%;
height: 15px;
width: 6px;
margin-left: -3px;
margin-top: -10px;
}
60% {
top: 50%;
height: 20px;
width: 10px;
margin-left: -5px;
}
70% {
top: 50%;
height: 40px;
width: 40px;
margin-left: -20px;
margin-top: -20px;
}
80% {
top: 50%;
height: 32px;
width: 32px;
margin-left: -16px;
margin-top: -16px;
}
90% {
top: 50%;
height: 24px;
width: 24px;
margin-left: -12px;
margin-top: -12px;
}
100% {
top: 50%;
height: 24px;
width: 24px;
margin-left: -12px;
margin-top: -12px;
}
}
@keyframes checkOut {
0% {
overflow: visible;
top: 50%;
width: 30px;
height: 30px;
margin-top: -17px;
margin-left: -17px;
border: 2px solid #009fd6;
opacity: 1;
}
100% {
width: 46px;
top: 50%;
height: 46px;
margin-top: -25px;
margin-left: -25px;
border: 2px solid #009fd6;
opacity: 0;
}
}
html,
body {
background: #000;
height: 100%;
width: 100%;
padding: 0;
margin: 0;
}
#container {
position: relative;
left: 50%;
top: 50%;
display: inline-block;
transform: translateX(-50%) translateY(-50%);
}
input#circle-input {
display: none;
}
input#circle-input:checked+label#circle-cont {
overflow: hidden;
}
input#circle-input:checked+label#circle-cont #circle {
background: #009fd6;
animation: checkIn 1s forwards linear 0s 1;
}
label#circle-cont {
border-radius: 50%;
width: 30px;
height: 30px;
border: 1px solid #FFF;
display: block;
position: relative;
float: left;
overflow: visible;
}
label#circle-cont #circle {
background: rgba(0, 0, 0, 0);
position: absolute;
left: 50%;
border-radius: 50%;
top: -100%;
animation: checkOut 0.25s forwards linear 0s 1;
}
label#label-name {
color: #FFF;
font-family: "Raleway", sans-serif;
position: relative;
float: left;
font-size: 1.25em;
margin: 4px 12px;
}
</style>
</head>
<body>
<div id="container">
<input type="checkbox" id="circle-input" />
<label for="circle-input" id="circle-cont">
<div id="circle"></div>
</label>
<label for="circle-input" id="label-name">Radio Button</label>
</div>
</body>
</html>