Three ways to achieve background blur in CSS3 (summary)

1. Normal background blur

Code:

<Style>
        html,
        body {
            width: 100%;
            height: 100%;
        }

        * {
            margin: 0;
            padding: 0;
        }

        /*Blurred background*/
        .bg {
            width: 100%;
            height: 100%;
            position: relative;
            background: url("./bg.jpg") no-repeat fixed;
            background-size: cover;
            box-sizing: border-box;
            filter: blur(2px);
            z-index: 1;
        }

        .content {
            position: absolute;
            left: 50%;
            top: 50%;
            transform: translate(-50%, -50%);
            width: 200px;
            height: 200px;
            text-align: center;
            z-index: 2;
        }
    </Style>
</head>

<body>
    <div class="bg">
        <div class="content">Blurred background</div>
    </div>
</body>

The effect is as follows:

Writing like this will make the entire div's descendants blurry and white edges will appear, making the page very unsightly. To solve this problem, we can use pseudo-elements, because the blurriness of pseudo-elements will not be inherited by the descendants of the parent element.

Code:

<Style>
        html,
        body {
            width: 100%;
            height: 100%;
        }

        * {
            margin: 0;
            padding: 0;
        }

        /*Blurred background*/
        .bg {
            width: 100%;
            height: 100%;
            position: relative;
            background: url("./bg.jpg") no-repeat fixed;
            background-size: cover;
            box-sizing: border-box;
            z-index: 1;
        }

        .bg:after {
            content: "";
            width: 100%;
            height: 100%;
            position: absolute;
            left: 0;
            top: 0;
            /* Inherit the background property settings from the parent element */
            background: inherit;
            filter: blur(2px);
            z-index: 2;
        }


        .content {
            position: absolute;
            left: 50%;
            top: 50%;
            transform: translate(-50%, -50%);
            width: 200px;
            height: 200px;
            text-align: center;
            z-index: 3;
        }
    </Style>
</head>

<body>
    <div class="bg">
        <div class="content">Blurred background</div>
    </div>
</body>

The effect is as follows:

2. Partial background blur

After you have mastered the previous effect, the local blur effect will be relatively simple.

Code:

<Style>
        html,
        body {
            width: 100%;
            height: 100%;
        }

        * {
            margin: 0;
            padding: 0;
        }

        /*Blurred background*/
        .bg {
            width: 100%;
            height: 100%;
            position: relative;
            background: url("./bg.jpg") no-repeat fixed;
            background-size: cover;
            box-sizing: border-box;
            z-index: 1;
        }

        .content {
            position: absolute;
            left: 50%;
            top: 50%;
            transform: translate(-50%, -50%);
            width: 200px;
            height: 200px;
            background: inherit;
            z-index: 2;
        }

        .content:after {
            content: "";
            width: 100%;
            height: 100%;
            position: absolute;
            left: 0;
            top: 0;
            background: inherit;
            filter: blur(15px);
            /*To make the blur more obvious, increase the blur*/
            z-index: 3;
        }

        .content>div {
            width: 100%;
            height: 100%;
            text-align: center;
            line-height: 200px;
            position: absolute;
            left: 0;
            top: 0;
            z-index: 4;
        }
    </Style>
</head>

<body>
    <div class="bg">
        <div class="content">
            <div>Partial background blur</div>
        </div>
    </div>
</body>

The effect is shown in the figure below:

3. Partial background clarity

Code:

<Style>
        html,
        body {
            width: 100%;
            height: 100%;
        }

        * {
            margin: 0;
            padding: 0;
        }

        /*Blurred background*/
        .bg {
            width: 100%;
            height: 100%;
            position: relative;
            background: url("./bg.jpg") no-repeat fixed;
            background-size: cover;
            box-sizing: border-box;
            z-index: 1;
        }

        .bg:after {
            content: "";
            width: 100%;
            height: 100%;
            position: absolute;
            left: 0;
            top: 0;
            background: inherit;
            filter: blur(5px);
            z-index: 2;
        }

        .content {
            position: absolute;
            left: 50%;
            top: 50%;
            transform: translate(-50%, -50%);
            width: 200px;
            line-height: 200px;
            text-align: center;
            background: inherit;
            z-index: 3;
            box-shadow: 0 0 10px 6px rgba(0, 0, 0, .5);
        }
    </Style>
</head>

<body>
    <div class="bg">
        <div class="content">
            <div>Partial background is clear</div>
        </div>
    </div>
</body>

The effect is shown in the figure below:

This concludes this article about three ways to achieve background blur with CSS3. For more relevant CSS3 background blur content, please search 123WORDPRESS.COM’s previous articles or continue browsing the related articles below. I hope you will support 123WORDPRESS.COM in the future!

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