css设置背景模糊

使用filter属性来设置模糊值

效果：

css设置背景模糊

css样式：

<style type="text/css">
        .cover {
            width: 600px;
            height: 300px;
            position: relative;
            text-align: center;
            line-height: 300px;
            color: #fff;
            margin: 20px auto;
        }
        
        .cover::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 600px;
            height: 300px;
            background: transparent url(Images/picture/5.jpg) center center no-repeat;
            filter: blur(8px);
            z-index: -1;
            background-size: cover;
        }
    </style>

HTML结构：

<body>
    <div class="cover">
        <h2>背景模糊，文字清晰显示</h2>
    </div>
</body>