CSS (Cascading Style Sheets) is a language used to describe the style and layout of a website. CSS can make a website more beautiful, easier to manage and expand. In CSS, there are many different terms and concepts, the most important of which are the differences between CSS.
In CSS, distinctions are used to indicate how different elements should be displayed and rendered. The difference is defined through selectors, one of the most fundamental concepts in CSS. Selectors allow us to select different elements in an HTML document so that they can be styled.
There are three different distinctions in CSS: category distinction, ID distinction and element distinction.
Category distinction is one of the most commonly used distinction types in CSS. Category distinctions use category selectors (starting with a period) to define the style of an element. For example, if you wanted to set the same style for all headings on your website, you could use the following code:
h1 { font-size: 24px; color: #000; }
This code block selects all h1 elements and sets their font size to 24 pixels and the font color Set to black.
ID distinctions are very similar to category distinctions, but they use ID selectors (# symbols). ID distinctions are used to uniquely identify an HTML element, and they can only be used once in a document. For example, if you wanted to style the header of your website, you could use the following code to define the ID distinction:
#header { background-color: #ccc; height: 100px; width: 100%; }
This code block selects an element with the ID "header" and sets its background Color, height and width. Please note that the ID selector is only used on a single element and the ID distinction cannot be reused in the document.
Element difference is the most basic type of difference in CSS. They use element selectors to select tags in HTML. For example, if you want to style all paragraphs, you can use the following code:
p { margin-bottom: 10px; line-height: 1.5; }
This code block selects all p elements and sets their bottom margin and line height.
In addition to the above three different types, CSS also supports other selector types, such as attribute selectors, sub-element selectors, adjacent element selectors, etc.
In actual work, it is very important to use the correct distinction. By choosing the right selector, you can avoid adding extra HTML elements to your website to define styles, making your code cleaner and easier to maintain while improving website performance and accessibility.
In short, the differences in CSS are very important concepts, and understanding them is an essential skill for every front-end developer. By choosing the right selectors and using them to define styles, you can make your website clearer, easier to manage, and more scalable.
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