CSS Specificity: A Beginner's Guide
CSS Specificity is a concept that determines which CSS styles will be applied to an HTML element. It is a way for the browser to decide which CSS rule should be applied to an element when there are multiple rules that apply to the same element. In this blog post, we will discuss the basics of CSS specificity and how it works.
CSS Specificity is determined by the number of each type of selector used in the CSS rule. The types of selectors are:
- ID selectors (#id)
- Class selectors (.)
- Element selectors (tag name)
- Pseudo-class selectors (:hover, :active, etc)
- Pseudo-element selectors (::before, ::after, etc)
The browser will apply the CSS rule with the highest specificity to an element. For example, if there are two rules that apply to the same element, one with an ID selector and one with a class selector, the rule with the ID selector will be applied because ID selectors have a higher specificity than class selectors.
When multiple selectors are used in a CSS rule, the specificity is calculated by adding up the values of each selector. For example, a CSS rule with one ID selector, two class selectors, and three element selectors would have a specificity of 1, 2, 3.
It's important to note that inline styles will always have the highest specificity, even if they have fewer selectors. So, an inline style will always override a CSS rule with a higher specificity.
CSS Specificity can also be affected by the location of the CSS rules. Styles that are declared later in the CSS will override styles that are declared earlier. This is known as the "cascade" and it's the reason why it's important to keep your CSS organized.
In addition to the CSS Specificity, the "!important" keyword can be used to override any other CSS rule. When a CSS property is marked as "!important", it will always be applied, regardless of the specificity of other rules. However, it's not recommended to use this keyword frequently, as it can make your CSS more difficult to maintain.
In conclusion, CSS Specificity is a way for the browser to decide which CSS rule should be applied to an element when there are multiple rules that apply to the same element. It is determined by the number of each type of selector used in the CSS rule and also by the location of the CSS rules. A good understanding of CSS Specificity will help you to write more organized and maintainable CSS.