现在，通过使用CSS GRID，这变得更加简单和灵活。你只需要将模糊的背景(imgbg)与文本(h2)重叠即可。

<div class="container">
 <div class="imgbg"></div>
 <h2>
  Lorem ipsum dolor sit amet consectetur, adipisicing elit. Facilis enim
  aut rerum mollitia quas voluptas delectus facere magni cum unde?:)
 </h2>
</div>

还有css:

.container {
        display: grid;
        width: 30em;
      }

.imgbg {
        background: url(bg3.jpg) no-repeat center;
        background-size: cover;
        grid-column: 1/-1;
        grid-row: 1/-1;
        filter: blur(4px);
      }


     .container h2 {
        text-transform: uppercase;
        grid-column: 1/-1;
        grid-row: 1/-1;
        z-index: 2;
      }

在CSS的.content选项卡中将其更改为position:absolute。否则，渲染的页面将不可滚动。

pen

取消了对额外元素的需求，同时使内容适合文档流，而不是像其他解决方案那样固定/绝对。

通过使用

.content { /* this is needed or the background will be offset by a few pixels at the top */ overflow: auto; position: relative; } .content::before { content: ""; position: fixed; left: 0; right: 0; z-index: -1; display: block; background-image: url('https://i.imgur.com/lL6tQfy.png'); background-size:cover; width: 100%; height: 100%; -webkit-filter: blur(5px); -moz-filter: blur(5px); -o-filter: blur(5px); -ms-filter: blur(5px); filter: blur(5px); } <div class="content"> Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. </div>

编辑如果你想删除边缘的白色边框，使用宽度和高度为110%，左侧和顶部为-5%。这将放大你的背景-但不应该有纯色从边缘流出。感谢Chad Fawcett的建议。

.content { /* this is needed or the background will be offset by a few pixels at the top */ overflow: auto; position: relative; } .content::before { content: ""; position: fixed; top: -5%; left: -5%; right: -5%; z-index: -1; display: block; background-image: url('https://i.imgur.com/lL6tQfy.png'); background-size:cover; width: 110%; height: 110%; -webkit-filter: blur(5px); -moz-filter: blur(5px); -o-filter: blur(5px); -ms-filter: blur(5px); filter: blur(5px); } <div class="content"> Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. </div>

如果你想要内容是可滚动的，设置内容的位置为绝对:

content {
   position: absolute;
   ...
}

我不知道这是不是只适合我，但如果不是，这就是解决办法!

此外，由于背景是固定的，这意味着你有一个“视差”效果!所以现在，这个人不仅教你如何制作一个模糊的背景，而且它也是一个视差背景效果!

这个答案是为材料设计水平卡片布局动态高度和图像。

为了防止由于卡片的动态高度而导致图像失真，您可以使用带有模糊的背景占位符图像来调整高度的变化。

解释

The card is contained in a <div> with class wrapper, which is a flexbox. The card is made up of two elements, an image which is also a link, and content. The link <a>, class link, is positioned relative. The link consists of two sub-elements, a placeholder <div> class blur and an <img> class pic which is the clear image. Both are positioned absolute and have width: 100%, but class pic has a higher stack order, i.e., z-index: 2, which places it above the placeholder. The background image for the blurred placeholder is set via inline style in the HTML.

Code

.wrapper { display: flex; width: 100%; border: 1px solid rgba(0, 0, 0, 0.16); box-shadow: 0 1px 1px rgba(0, 0, 0, 0.16), 0 1px 1px rgba(0, 0, 0, 0.23); background-color: #fff; margin: 1rem auto; height: auto; } .wrapper:hover { box-shadow: 0 3px 6px rgba(0, 0, 0, 0.16), 0 3px 6px rgba(0, 0, 0, 0.23); } .link { display: block; width: 200px; height: auto; overflow: hidden; position: relative; border-right: 2px solid #ddd; } .blur { position: absolute; top: 0; left: 0; right: 0; bottom: 0; margin: auto; width: 100%; height: 100%; filter: blur(5px); -webkit-filter: blur(5px); -moz-filter: blur(5px); -o-filter: blur(5px); -ms-filter: blur(5px); } .pic { width: calc(100% - 20px); max-width: 100%; height: auto; margin: auto; position: absolute; top: 0; left: 0; right: 0; bottom: 0; z-index: 2; } .pic:hover { transition: all 0.2s ease-out; transform: scale(1.1); text-decoration: none; border: none; } .content { display: flex; flex-direction: column; width: 100%; max-width: 100%; padding: 20px; overflow-x: hidden; } .text { margin: 0; } <div class="wrapper"> <a href="#" class="link"> <div class="blur" style="background: url('https://i.imgur.com/5SZI6qZ.jpeg') 50% 50% / cover;"></div> <img src="https://i.imgur.com/5SZI6qZ.jpeg" alt="Title" class="pic" /> </a> <div class="content"> <p class="text">Agendum dicendo memores du gi ad. Perciperem occasionem ei ac im ac designabam. Ista rom sibi vul apud tam. Notaverim to extendere expendere concilium ab. Aliae cogor tales fas modus parum sap nullo. Voluntate ingressus infirmari ex mentemque ac manifeste eo. Ac gnum ei utor sive se. Nec curant contra seriem amisit res gaudet adsunt. </p> </div> </div>

正如在其他答案中所述，这可以通过以下方式实现:

作为背景的模糊图像的副本。 可以过滤的伪元素，然后将其定位在内容后面。

你也可以使用backdrop-filter

有一个受支持的属性叫做backdrop-filter，目前是 支持Chrome, Firefox, Edge, Safari和iOS Safari(查看caniuse.com统计数据)。

来自Mozilla devdocs:

backdrop-filter属性提供了一些效果，比如对元素后面的区域进行模糊或颜色移动，然后通过调整元素的透明度/不透明度就可以看到元素。

查看caniuse.com了解使用统计数据。

你会这样使用它。 如果你不想让里面的内容被模糊化，使用实用工具类.u-non- ambiguous

.background-filter::after { -webkit-backdrop-filter: blur(5px); /* Use for Safari 9+, Edge 17+ (not a mistake) and iOS Safari 9.2+ */ backdrop-filter: blur(5px); /* Supported in Chrome 76 */ content: ""; display: block; position: absolute; width: 100%; height: 100%; top: 0; } .background-filter { position: relative; } .background { background-image: url('https://upload.wikimedia.org/wikipedia/en/6/62/Kermit_the_Frog.jpg'); width: 200px; height: 200px; } /* Use for content that should not be blurred */ .u-non-blurred { position: relative; z-index: 1; } <div class="background background-filter"></div> <div class="background background-filter"> <h1 class="u-non-blurred">Kermit D. Frog</h1> </div>