CSS：图像预览 - 悬停时的圆形到矩形

Question

这是一个公认的简单问题，在这里可能已经问过，但我在这里遇到了困难。

我想要的是具有圆形预览的图像，该图像在悬停时扩展为矩形（它也可以缩放）。我所拥有的非常接近，但中心有点“泡泡”，我不喜欢空 div 方法......

.card{
   color: #ff2772;
   border-radius: 15px;
   margin: 3px 1px;
   background-color: #2d3034;
   box-sizing: border-box;
   width: 300px;
   min-height: 400px;
   display: inline-block;
   transition: .25s;
   cursor:pointer;
   text-align: center;
   border: 1px solid #ff2772;
}

.button {
   background-color: #ff2772;
   color: #fff;
   padding: 10px 30px;
   border-radius: 10px;
}

#seasonOne .test {
   background: url('http://placehold.it/250x200') 50% 50% no-repeat; 
   width: 200px;
   height: 200px;
   border-radius: 100%;
   display: block;
   margin: 0 auto;
   transition: .3s;
   transform: scale(.9);
}

#seasonOne:hover .test {
   transform: scale(1);
   width: 250px;
   height: 200px;
   border-radius: 0;
}

<div id="seasonOne" class="card seasonOne">
   <h3>Season 1 (2009) - The Pilot</h3>
   <div class="test">
   </div>
   <p class="animated smallText fadeInRight">Ut cursus purus in lacinia tincidunt. Quisque lorem odio, posuere ut aliquam vel, fringilla at enim. Duis ligula lacus, viverra et sapien rhoncus, commodo euismod ipsum.</p>
   <a href="#area" class="button">Read More</a>
</div>

就像我说的，我所拥有的非常接近。它只是没有正确居中，这让我发疯。我也不喜欢在 CSS 而不是 HTML 中设置图像（虽然这是一个小问题）关于更好的解决方法有什么想法吗？

编辑：好的澄清一下：

1.) 0.9 到 1 的比例是有意的

2.) 矩形比例 (250x200px) 很重要。它不应该是一个完美的正方形。

3.) 当我说中心“晃动”时，我的意思是它偏离了。它很微妙，但它会围绕几个像素移动。遗憾的是，我认为问题并没有出现在我的 sn-p 中，这意味着它是来自我的 CSS 中的其他地方：/ 这是我网站上的（抱歉，可爱的艺术）

我想一个更好的问题是如何在没有空 div 并保证居中的情况下实现这种效果？

编辑 2： 问题出在 Firefox 中。您可以在此 Codepen 中看到艺术“振动” http://codepen.io/StuffieStephie/pen/zrZwEQ

Answer 1

你得到 bobbbling 事件的原因

您在悬停时设置了一个过渡属性，其中包括将元素缩放到更大的尺寸。因此，背景图像随着 div 的缩放而缩放。此外，您正在做的是设置一个不相关的增加宽度，因为转换比例也在做同样的事情

改变

#seasonOne:hover .test {
   transform: scale(1);
   width: 250px;
   height: 200px;
   border-radius: 0;
}

到

#seasonOne:hover .test {
        border-radius: 0;
}

这是一个sn-p

.card{
	color: #ff2772;
	border-radius: 15px;
	margin: 3px 1px;
	background-color: #2d3034;
	box-sizing: border-box;
	width: 300px;
	min-height: 400px;
	display: inline-block;
	transition: .25s;
	cursor:pointer;
  text-align: center;
			border: 1px solid #ff2772;
}

.button {
background-color: #ff2772;
  color: #fff;
  padding: 10px 30px;
  border-radius: 10px;
}

#seasonOne .test {
background: url('http://placehold.it/250x200') 50% 50% no-repeat; /* 50% 50% centers image in div */
width: 200px;
height: 200px;
border-radius: 100%;
display: block;
margin: 0 auto;
transition-property:border;
transition: .3s;
transform: scale(.9);
}

#seasonOne:hover .test {
   border-radius: 0;
}

<div id="seasonOne" class="card seasonOne">
	<h3>Season 1 (2009) - The Pilot</h3>
	<div class="test">
	</div>
	<p class="animated smallText fadeInRight">Ut cursus purus in lacinia tincidunt. Quisque lorem odio, posuere ut aliquam vel, fringilla at enim. Duis ligula lacus, viverra et sapien rhoncus, commodo euismod ipsum.</p>
<a href="#area" class="button">Read More</a>
</div>

编辑：看这里的 codepen 是一个 sn-p

.season img {
	float: left;
	max-width: 500px;
	width: 100%;
	animation-delay:0.1s; 
}

.season p.oneP {
animation-delay:0.5s; 
}
  
.season p.twoP {
animation-delay:0.75s; 
}
.season p.threeP {
animation-delay:1s; 
}
.season h2 {
	border-radius: 10px 10px 0 0;
background-color: #eee;
padding: 3px;
margin-top: 0;
overflow-x: hidden;
}
.season .smallText {
	animation-delay:0.2s; 
	overflow: hidden;
}
.season h6, .season .arts, .season h3 {
	text-align: center !important;
	animation-delay: 1.8s;
}
.next, .prev {
float: right;
 box-sizing: border-box;
	width: 49%;
	animation-delay: 3s;
	border: 3px solid #EEE;
	border-radius: 15px;
}
.prev {
	float: left;
}
	.prev img.preview, .next img.preview {
		float: left;
	}
.previews {
	display: -webkit-flex; /* Safari */
    -webkit-justify-content: space-around; /* Safari 6.1+ */
    display: flex;
    justify-content: space-around;
     flex-wrap: wrap;
}
.card{
	color: #ff2772;
	border-radius: 15px;
	margin: 3px 1px;
	background-color: #2d3034;
	box-sizing: border-box;
	width: 300px;
	min-height: 400px;
	display: inline-block;
	transition: .25s;
	cursor:pointer;
			border: 1px solid #ff2772;
			text-align: center;
}
.floatRight {
	float: right;
	margin-right: 10px;
	
}
#page-content .card h6 {
	padding: 10px 2px;
	background: none;
	border-radius: 10px 10px 0 0;
	transition: .3s;
	
	border-bottom: 1px solid #fff;
}


#page-content .card .smallText {
transition: .3s;
	background: none;
	border-bottom: 1px solid #fff;
	border-top: 1px solid #fff;
}

#page-content .card:hover .smallText, #page-content .card:hover h6{
	background-color: #ff2772;
	color: #2d3034;
}
.card:hover{
	background: #fff;
}

/*
.card img {
	width: 200px;
	text-align: center;
	border-radius: 100%;
	background: #fff;
	margin: 0 auto;
	display: block;
		transform: scale(.9);
    transition: all .2s ease-in-out;
	
}
/*.card .test {
	transform: scale(.9);
	width: 200px;
	height: 200px;
	overflow-x: hidden;
	display: block;
	margin: 0 auto;

}
*/




#seasonOne .test {
	padding:0;
		background-color: #fff;
	background: #fff url('http://i296.photobucket.com/albums/mm174/StuffieStephie/S1ChibiPreview2_zpsswyamase.png') 50% 50% no-repeat;
width: 200px;
height: 200px;
	border-radius: 50%;
	display: block;
		margin: 0 auto;
	-webkit-transition: 0.5s;
	        -moz-transition: 0.5s;
	        transition: 0.5s;
	-webkit-transform: scale(.9);
	    -ms-transform: scale(.9);
	    -moz-transform: scale(.9);
	        transform: scale(.9);
	font-size: 0;
	-webkit-transform-origin: 50% 50%;
	-moz-transform-origin: 50% 50%;
	    -ms-transform-origin: 50% 50%;
	        transform-origin: 50% 50%;

}

#seasonOne:hover .test {
	border-radius: 0;
}



hr {
	margin: 0;
	padding: 0;
}
img.preview {
	transform: scale(.9);
	width: 200px;
	display: inline;
	float: none;
		border-radius: 10px;
    transition: all .2s ease-in-out;
    box-shadow: 0 1px 1px rgba(0,0,0,0.3);
    border-radius: 10px;
    line-height: 0;
    font-size: 0;
}
.art img.preview:nth-child(1) {
		animation-delay: 2s;
}
.art img.preview:nth-child(2) {
		animation-delay: 2.25s;
}

.logo{
	clear:left;
	padding-bottom: 10px;
}
img.preview:hover {
	transform: scale(1);
	box-shadow: 0 15px 15px rgba(0,0,0,0.3);
	border-radius: 0;
}
.season img.no-float {
		float: none;
}
@media screen and (max-width: 1200px) {
		.season h6 {
		clear: both;
	}
}
@media screen and (max-width: 800px) {	
	.prev img.preview, .next img.preview {
		float: left;
	}

	.season p {
		clear: both;
	}
			.prev p, .next p {
		clear: none;
	}
	.season img{
		float: none;
margin: 0 auto;
text-align: center;
	}
}
@media screen and (max-width: 750px) {	
	.card {
		width: 49%;
		box-sizing: border-box;
	}
	}
@media screen and (max-width: 600px) {

.prev, .next{
	width: 100%;
	float: none;
	margin: 5px auto;
}
	.prev img.preview, .next img.preview {
	}
}
@media screen and (max-width: 399px) {
	.card{
	width: 100%;
	}
}

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<section><h1>Help Me!</h1>
<p>The art shakes horribly when you hover over it in Firefox Why!?</p>
<div id="area" class="holder"></div>
<div class="previews">
<div id="seasonOne" class="card seasonOne">
	<h6 class="center">Season 1 (2009) - The Pilot</h6>
	<div class="test"></div>
	<p class="animated smallText fadeInRight oneP">Ut cursus purus in lacinia tincidunt. Quisque lorem odio, posuere ut aliquam vel, fringilla at enim. Duis ligula lacus, viverra et sapien rhoncus, commodo euismod ipsum.</p>
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