What are pseudo-classes and pseudo-elements? Detailed explanation of the difference between pseudo-classes and pseudo-elements

Use the :nth-child(n+3) pseudo-class selector to select the style of child elements whose position is greater than or equal to 3. The specific code example is as follows: HTML code: <divid="container"><divclass="item"&gt ;First child element</div><divclass="item"&

Reasons for pseudo-element failure: 1. Selector issues; 2. Style conflicts; 3. Inheritance issues; 4. Syntax errors; 5. Browser compatibility issues, etc. Detailed introduction: 1. Selector problem, the selector of the pseudo element may be incorrect, resulting in the target element not being selected; 2. Style conflict, if there is a style conflict in CSS, the pseudo element may become invalid; 3. Inheritance problem, Pseudo elements may not inherit certain style attributes; 4. Syntax errors. If there are syntax errors in CSS, the pseudo elements may fail; 5. Browser compatibility issues, etc.

Implementing multiple application scenarios of the CSS::placeholder pseudo-element selector requires specific code examples. In web development, CSS is a commonly used style sheet language used to control the layout and style of web pages. The ::placeholder pseudo-element selector is a new selector in CSS3, which is used to modify the placeholder style of input boxes (including text input boxes, password input boxes, etc.). Below we will introduce various application scenarios and provide corresponding code examples. Modify the color of the input box placeholder:

In the previous article "Css Pseudo-Selector Learning - Pseudo-Element Selector Analysis", we learned about pseudo-element selectors, and today we take a closer look at pseudo-class selectors. I hope it will be helpful to everyone!

Hover is not a pseudo-element, it is a pseudo-class. Pseudo-classes are used to select a specific state or behavior of an element, while pseudo-elements are used to add styles to specific parts of an element. Because :hover is used to select a specific state of an element rather than adding styles to a specific part of the element, you can use the :hover pseudo-class to style the mouseover state of an element, and you can use the :hover pseudo-class to add hover effects to links. The link's color, background color, etc. can change when the mouse hovers over it.

CSS styles using the :active pseudo-class selector to achieve mouse click effects CSS is a cascading style sheet language used to describe the performance and style of web pages. :active is a pseudo-class selector in CSS, used to select the state of an element when the mouse is clicked. By using the :active pseudo-class selector, we can add specific styles to the clicked element to achieve the mouse click effect. The following is a simple sample code that demonstrates how to use the :active pseudo-class selector to achieve a mouse click effect.

Pseudo elements can be used to create decorative effects, achieve specific layout effects, create interactive effects, modify specific element states and create some special effects. Detailed introduction: 1. Create decorative effects. By setting the content attributes and styles of the :before or :after pseudo-element, you can insert icons, shapes or other decorative elements before or after the element, so that you can add more elements to the web page. Visual appeal and personalization; 2. Achieve specific layout effects, which can be created through :before and :after pseudo-elements, etc.

Understand the basic concepts and application scenarios of CSS pseudo-classes and pseudo-elements. CSS (CascadingStyleSheets) is a markup language used to describe the style of web pages. It can control the appearance and layout of elements in web pages. In CSS, pseudo-classes and pseudo-elements are very useful features that can further expand the application scope and flexibility of CSS. 1. Pseudo-classes Pseudo-classes are keywords used to select specific state elements. Common pseudo-classes include: hover, active, focus, etc. Here are some common