使用此half slider startboostrap template，我尝试在图片中添加zoom effect。
缩放效果不起作用。我认为这是因为CSS以IMG标签为目标。有没有办法使用轮播图像作为CSS背景？
@-webkit-keyframes zoom {
from {
-webkit-transform: scale(1, 1);
}
to {
-webkit-transform: scale(1.5, 1.5);
}
}
@keyframes zoom {
from {
transform: scale(1, 1);
}
to {
transform: scale(1.5, 1.5);
}
}
.carousel-item > img {
-webkit-animation: zoom 20s;
animation: zoom 20s;
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="description" content="">
<meta name="author" content="">
<title>Half Slider - Start Bootstrap Template</title>
<!-- Bootstrap core CSS -->
<link href="vendor/bootstrap/css/bootstrap.min.css" rel="stylesheet">
<!-- Custom styles for this template -->
<link href="css/half-slider.css" rel="stylesheet">
</head>
<body>
<!-- Navigation -->
<nav class="navbar navbar-expand-lg navbar-dark bg-dark fixed-top">
<div class="container">
<a class="navbar-brand" href="#">Start Bootstrap</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarResponsive" aria-controls="navbarResponsive" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarResponsive">
<ul class="navbar-nav ml-auto">
<li class="nav-item active">
<a class="nav-link" href="#">Home
<span class="sr-only">(current)</span>
</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">About</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Services</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Contact</a>
</li>
</ul>
</div>
</div>
</nav>
<header>
<div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">
<ol class="carousel-indicators">
<li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
<li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
<li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
</ol>
<div class="carousel-inner" role="listbox">
<!-- Slide One - Set the background image for this slide in the line below -->
<div class="carousel-item active" style="background-image: url('images/road/road12.jpg')">
<div class="carousel-caption d-none d-md-block">
<h3>First Slide</h3>
<p>This is a description for the first slide.</p>
</div>
</div>
<!-- Slide Two - Set the background image for this slide in the line below -->
<div class="carousel-item" style="background-image: url('images/road/road14.jpg')">
<div class="carousel-caption d-none d-md-block">
<h3>Second Slide</h3>
<p>This is a description for the second slide.</p>
</div>
</div>
<!-- Slide Three - Set the background image for this slide in the line below -->
<div class="carousel-item" style="background-image: url('images/road/road5.jpg')">
<div class="carousel-caption d-none d-md-block">
<h3>Third Slide</h3>
<p>This is a description for the third slide.</p>
</div>
</div>
</div>
<a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
<span class="carousel-control-prev-icon" aria-hidden="true"></span>
<span class="sr-only">Previous</span>
</a>
<a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
<span class="carousel-control-next-icon" aria-hidden="true"></span>
<span class="sr-only">Next</span>
</a>
</div>
</header>
<!-- Page Content -->
<section class="py-5">
<div class="container">
<h1>Half Slider by Start Bootstrap</h1>
<p>The background images for the slider are set directly in the HTML using inline CSS. The rest of the styles for this template are contained within the
<code>half-slider.css</code>file.</p>
</div>
</section>
<!-- Footer -->
<footer class="py-5 bg-dark">
<div class="container">
<p class="m-0 text-center text-white">Copyright © Your Website 2017</p>
</div>
<!-- /.container -->
</footer>
<!-- Bootstrap core JavaScript -->
<script src="vendor/jquery/jquery.min.js"></script>
<script src="vendor/bootstrap/js/bootstrap.bundle.min.js"></script>
</body>
</html>
模板效果很好，但缩放功能根本不起作用。