How to read css-Front-end Q&A-php.cn

CSS (Cascading Style Sheets) is a markup language used to control the style and layout of web pages. It is an indispensable part of web design and can make web pages more beautiful, easy to read, and easy to use. But for beginners, the word CSS is not only difficult to read, but also not easy to understand. This article will introduce you to the reading, usage and precautions of CSS from three aspects.

1. The pronunciation of CSS

CSS is an English word abbreviation, and the pronunciation is "C-S-S". Specifically, the pronunciation of each letter is as follows:

C: pronounced as "see", indicating cascading;

S: pronounced as "ess", indicating style ( Style);

S: still pronounced as "ess", indicating tables (Sheets).

Therefore, the pronunciation of CSS is SEE-ess-ess. Of course, even if there are different pronunciations, as long as you can accurately understand and use CSS.

2. How to use CSS

1. Internal style sheet

The internal style sheet is a way to write CSS styles directly in the HTML document, that is, by Use the tag within the tag to define the style. The advantage of this method is that it is convenient and intuitive, and there is no need to reference CSS styles separately in each HTML document. But the disadvantage is that it increases the size of the HTML document and makes it difficult to maintain and update styles.

2. External style sheet

External style sheet is a way to use a separate CSS file to define styles, that is, use the tag to reference the CSS file into the HTML document. The advantage of this method is that it can separate styles and content, and the styles can be shared in multiple HTML documents for easy maintenance and updates. But the disadvantage is that it requires additional CSS files and HTTP requests, which increases web page loading time.

3. Inline style

Inline style is a way to directly define the style in the HTML tag, that is, use the style attribute within the tag to specify the style. The advantage of this method is that it is direct and effective, does not require additional CSS files or selectors, and is suitable for some temporary style adjustments. But the disadvantage is that it is not easy to maintain and it is not easy to apply to multiple tags.

3. Notes on CSS

1. Priority of selector

The priority of CSS selector refers to when multiple style definitions act on the same element at the same time , which style overrides the other. The priority of the selector is composed of the selector type, category and quantity. It is generally judged in the following order:

(1) The ID selector has the highest priority and has a weight of 100;

(2) The class selector and attribute selector have the same priority, with 10 weights;

(3) The label selector has the lowest priority, with 1 weight.

2. Style inheritance

CSS styles can be inherited, that is, the style of the parent element will affect the child elements. But not all styles are inherited. Usually only text properties, list properties, table layout properties, etc. are inherited. Some box layout properties, positioning properties, background properties, etc. are not inherited.

3. Browser compatibility issues

Different browsers may have different levels of support for CSS styles, resulting in inconsistent display effects between different browsers. In order to avoid this situation, it is recommended to pay attention to compatibility issues when writing CSS styles. You can use the browser manufacturer's prefix or add other hack codes to solve compatibility issues.

In short, CSS is an extremely important part of web design. Being proficient in the usage and precautions of CSS can greatly improve the quality and efficiency of web design.