代碼如下
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<style>
.point {
width: 50px;
height: 50px;
background-color: #2ea598;
position: relative;
border-radius: 50%;
}
/* 設置動畫前顏色 */
.point-flicker:after {
background-color: #2ea598;
}
/* 設置動畫後顏色 */
.point-flicker:before {
background-color: rgba(0, 168, 253, 0.2);
}
/* 設置動畫 */
.point-flicker:before,
.point-flicker:after {
content: '';
width: 80px;
height: 80px;
position: absolute;
left: 50%;
top: 50%;
margin-left: -40px;
margin-top: -40px;
border-radius: 50%;
/* CSS3 animation 屬性 網址 */
/* https://www.w3school.com.cn/cssref/pr_animation.asp */
animation: warn 1.5s ease-out 0s infinite;
}
/* @keyframes 規則用於創建動畫。在 @keyframes 中規定某項 CSS 樣式，就能創建由當前樣式逐漸改爲新樣式的動畫效果。 */
@keyframes warn {
0% {
transform: scale(0.5);
opacity: 1;
}
30% {
opacity: 1;
}
100% {
transform: scale(1.4);
opacity: 0;
}
}
</style>
<body>
<div class="point point-flicker">
</div>
</body>
<script>
</script>
</html>
效果如圖
![]()
