How to introduce css into html
How to introduce CSS into HTML
As the basis of front-end development, the relationship between HTML and CSS complements each other. HTML is responsible for building the page structure and content, while CSS is responsible for adding color and beautifying the page on this basis. So, how to introduce CSS styles into HTML documents? This article will introduce how to introduce CSS and what to pay attention to.
- Refer external CSS in the HTML header
This is the most common and recommended way to reference CSS. Taking the common page structure as an example, add a link tag in the HTML header tag:
<!DOCTYPE html> <html> <head> <title>标题</title> <link rel="stylesheet" type="text/css" href="style.css"> </head> <body> 页面内容 </body> </html>
Among them, the link tag has three attributes:
- rel: represents the style sheet and The relationship of the current document is an external style sheet, and the value is "stylesheet";
- type: indicates the MIME type of the style sheet file, and the value is "text/css";
- href: indicates The reference path to the style sheet file.
It should be noted here that the path of the href attribute should be based on the current HTML path, not the relative path where the CSS file is located. Assuming that the CSS file is in the same directory as the current HTML, the reference style should be written like this:
<link rel="stylesheet" type="text/css" href="./style.css">
where "." indicates the current directory, and the file name suffix ".css" cannot be omitted.
- Embed internal CSS in the HTML header
In HTML documents, we can embed internal CSS through the style tag. This method inevitably increases the size of the HTML file, but for some simple and small websites, it can save the request and download time of external files and speed up the page response speed. The following is a sample code:
<!DOCTYPE html> <html> <head> <title>标题</title> <style type="text/css"> /* CSS样式内容 */ body {background-color: #F1F1F1;} h1 {color: orange;} </style> </head> <body> 页面内容 </body> </html>
Among them, the content in the style tag has the same format as the external CSS file, except that the style code is written directly inside the style tag. It should be noted that in order to avoid style pollution (CSS styles affecting each other), internal CSS should use meaningful CSS selectors to limit the scope of styles.
- Embedding inline styles in HTML elements
Inline styles refer to embedding CSS style code directly into the style attribute of HTML elements. This method is extremely flexible, but it is not conducive to code reuse and maintenance. The following is sample code:
<!DOCTYPE html> <html> <head> <title>标题</title> </head> <body> <h1 style="color:orange;">页面标题</h1> <p style="font-size:18px;">页面内容</p> </body> </html>
It should be noted that when using inline styles, you should ensure that the style code does not affect the accessibility (Accessibility) and usability (Usability) of the page. For some styles similar to visual effects, you should use external styles or internal styles.
References:
- W3Schools. CSS - External Style Sheets
- W3Schools. CSS - Internal Styles
- W3Schools. CSS - Inline Styles
- Study Notes: Basic Knowledge of HTML and CSS
The above is the detailed content of How to introduce css into html. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

React combines JSX and HTML to improve user experience. 1) JSX embeds HTML to make development more intuitive. 2) The virtual DOM mechanism optimizes performance and reduces DOM operations. 3) Component-based management UI to improve maintainability. 4) State management and event processing enhance interactivity.

React is the preferred tool for building interactive front-end experiences. 1) React simplifies UI development through componentization and virtual DOM. 2) Components are divided into function components and class components. Function components are simpler and class components provide more life cycle methods. 3) The working principle of React relies on virtual DOM and reconciliation algorithm to improve performance. 4) State management uses useState or this.state, and life cycle methods such as componentDidMount are used for specific logic. 5) Basic usage includes creating components and managing state, and advanced usage involves custom hooks and performance optimization. 6) Common errors include improper status updates and performance issues, debugging skills include using ReactDevTools and Excellent

React components can be defined by functions or classes, encapsulating UI logic and accepting input data through props. 1) Define components: Use functions or classes to return React elements. 2) Rendering component: React calls render method or executes function component. 3) Multiplexing components: pass data through props to build a complex UI. The lifecycle approach of components allows logic to be executed at different stages, improving development efficiency and code maintainability.

The advantages of React are its flexibility and efficiency, which are reflected in: 1) Component-based design improves code reusability; 2) Virtual DOM technology optimizes performance, especially when handling large amounts of data updates; 3) The rich ecosystem provides a large number of third-party libraries and tools. By understanding how React works and uses examples, you can master its core concepts and best practices to build an efficient, maintainable user interface.

The React ecosystem includes state management libraries (such as Redux), routing libraries (such as ReactRouter), UI component libraries (such as Material-UI), testing tools (such as Jest), and building tools (such as Webpack). These tools work together to help developers develop and maintain applications efficiently, improve code quality and development efficiency.

React is a JavaScript library for building user interfaces, with its core components and state management. 1) Simplify UI development through componentization and state management. 2) The working principle includes reconciliation and rendering, and optimization can be implemented through React.memo and useMemo. 3) The basic usage is to create and render components, and the advanced usage includes using Hooks and ContextAPI. 4) Common errors such as improper status update, you can use ReactDevTools to debug. 5) Performance optimization includes using React.memo, virtualization lists and CodeSplitting, and keeping code readable and maintainable is best practice.

React is a front-end framework for building user interfaces; a back-end framework is used to build server-side applications. React provides componentized and efficient UI updates, and the backend framework provides a complete backend service solution. When choosing a technology stack, project requirements, team skills, and scalability should be considered.

React's main functions include componentized thinking, state management and virtual DOM. 1) The idea of componentization allows splitting the UI into reusable parts to improve code readability and maintainability. 2) State management manages dynamic data through state and props, and changes trigger UI updates. 3) Virtual DOM optimization performance, update the UI through the calculation of the minimum operation of DOM replica in memory.
