请问这种背景黑框固定的效果如何实现的？是css还是js_html/css

Home

Web Front-end

HTML Tutorial

请问这种背景黑框固定的效果如何实现的？是css还是js_html/css_WEB-ITnose

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

Jun 24, 2016 am 11:22 AM

http://mindhacks.com/

需用电脑访问，手机看不到效果，请问这种背景黑框固定的效果如何实现的？不管右侧浏览器滚动条如何滚动，黑色背景边框都不变，我研究了半天没想明白，是css还是js？请大神指导！

回复讨论(解决方案)

通过CSS实现的，手机看不到效果的原因是响应式页面

原理如下：
设置body的背景色为#1a1a1a 深灰，这样左右的黑框就有了
然后通过伪类选择器:before & :after实现上下的黑框，定位设置为fixed相对浏览器窗口定位，设置一定的高度，这样上下的黑框也有了

你试试下面简化的样式就明白了

<!doctype html><html><head><meta charset="utf-8"><title>无标题文档</title><style>body:before {		background: inherit;		content: "";		display: block;		height: 21px;		left: 0;		top:0;		position: fixed;		width: 100%;		z-index: 99;}body:after {		background: inherit;		content: "";		display: block;		height: 21px;		left: 0;		bottom:0;		position: fixed;		width: 100%;		z-index: 99;}body {		background:#1a1a1a;}#div1 {	margin:21px;	background:#fff;	max-width:1320px;}</style></head><body><div id="div1">    <div>我是内容我是内容</div>    <div>我是内容我是内容</div>    <div>我是内容我是内容</div>    <div>我是内容我是内容</div>    <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>    <div>我是内容我是内容</div>    <div>我是内容我是内容</div>    <div>我是内容我是内容</div>    <div>我是内容我是内容</div>    <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>    <div>我是内容我是内容</div>    <div>我是内容我是内容</div>    <div>我是内容我是内容</div>    <div>我是内容我是内容</div></div></body></html>

非常感谢呀，以前没用过before和after，多谢，请问这两个是不是都是CSS的标签，需要浏览器支持？

<!doctype html><html lang="en"><head>	<meta charset="UTF-8" />	<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />	<title> 页面名称 </title><style type="text/css">body {	border: 20px solid rgb(25,25,25);	padding: 0px;	margin: 0px;}body:before {	content: "";	background-color: rgb(25,25,25);	position: fixed;	left: 0;	top: 0;	width: 100%;	height: 20px;}body:after {	content: "";	background-color: rgb(25,25,25);	position: fixed;	left: 0;	bottom: 0;	width: 100%;	height: 20px;}#div {	width: 100%;	height: 2000px;}</style></head><body><div id="div"></div></body></html>

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

HTML as a Markup Language: Its Function and PurposeApr 22, 2025 am 12:02 AM

The function of HTML is to define the structure and content of a web page, and its purpose is to provide a standardized way to display information. 1) HTML organizes various parts of the web page through tags and attributes, such as titles and paragraphs. 2) It supports the separation of content and performance and improves maintenance efficiency. 3) HTML is extensible, allowing custom tags to enhance SEO.

The Future of HTML, CSS, and JavaScript: Web Development TrendsApr 19, 2025 am 12:02 AM

The future trends of HTML are semantics and web components, the future trends of CSS are CSS-in-JS and CSSHoudini, and the future trends of JavaScript are WebAssembly and Serverless. 1. HTML semantics improve accessibility and SEO effects, and Web components improve development efficiency, but attention should be paid to browser compatibility. 2. CSS-in-JS enhances style management flexibility but may increase file size. CSSHoudini allows direct operation of CSS rendering. 3.WebAssembly optimizes browser application performance but has a steep learning curve, and Serverless simplifies development but requires optimization of cold start problems.

HTML: The Structure, CSS: The Style, JavaScript: The BehaviorApr 18, 2025 am 12:09 AM

The roles of HTML, CSS and JavaScript in web development are: 1. HTML defines the web page structure, 2. CSS controls the web page style, and 3. JavaScript adds dynamic behavior. Together, they build the framework, aesthetics and interactivity of modern websites.

The Future of HTML: Evolution and Trends in Web DesignApr 17, 2025 am 12:12 AM

The future of HTML is full of infinite possibilities. 1) New features and standards will include more semantic tags and the popularity of WebComponents. 2) The web design trend will continue to develop towards responsive and accessible design. 3) Performance optimization will improve the user experience through responsive image loading and lazy loading technologies.

HTML vs. CSS vs. JavaScript: A Comparative OverviewApr 16, 2025 am 12:04 AM

The roles of HTML, CSS and JavaScript in web development are: HTML is responsible for content structure, CSS is responsible for style, and JavaScript is responsible for dynamic behavior. 1. HTML defines the web page structure and content through tags to ensure semantics. 2. CSS controls the web page style through selectors and attributes to make it beautiful and easy to read. 3. JavaScript controls web page behavior through scripts to achieve dynamic and interactive functions.

HTML: Is It a Programming Language or Something Else?Apr 15, 2025 am 12:13 AM

HTMLisnotaprogramminglanguage;itisamarkuplanguage.1)HTMLstructuresandformatswebcontentusingtags.2)ItworkswithCSSforstylingandJavaScriptforinteractivity,enhancingwebdevelopment.

HTML: Building the Structure of Web PagesApr 14, 2025 am 12:14 AM

HTML is the cornerstone of building web page structure. 1. HTML defines the content structure and semantics, and uses, etc. tags. 2. Provide semantic markers, such as, etc., to improve SEO effect. 3. To realize user interaction through tags, pay attention to form verification. 4. Use advanced elements such as, combined with JavaScript to achieve dynamic effects. 5. Common errors include unclosed labels and unquoted attribute values, and verification tools are required. 6. Optimization strategies include reducing HTTP requests, compressing HTML, using semantic tags, etc.

From Text to Websites: The Power of HTMLApr 13, 2025 am 12:07 AM

HTML is a language used to build web pages, defining web page structure and content through tags and attributes. 1) HTML organizes document structure through tags, such as,. 2) The browser parses HTML to build the DOM and renders the web page. 3) New features of HTML5, such as, enhance multimedia functions. 4) Common errors include unclosed labels and unquoted attribute values. 5) Optimization suggestions include using semantic tags and reducing file size.

See all articles