How Can I Override Browser Default Styles (User Agent Stylesheets)?

Understanding User Agent Stylesheets

When creating web pages, we define CSS rules to control the appearance and layout of our content. However, browsers often apply their own default stylesheets, known as user agent stylesheets.

What is a User Agent Stylesheet?

A user agent stylesheet is a set of default CSS rules pre-defined by the browser. These rules aim to provide a consistent base style for all web pages, ensuring a minimum level of functionality and readability. The styles specified in the user agent stylesheet are applied automatically, even if you haven't defined your own styles.

Overriding User Agent Styles

In your example, you noticed that Chrome applies its user agent stylesheet, which includes a font-size property that conflicts with your design. To override these default styles, you can use two approaches:

1. CSS Reset

CSS resets are stylesheets that eliminate the default styles of browsers. By including a CSS reset at the beginning of your stylesheet, you can remove all browser-defined styles and start with a clean slate. Some popular CSS resets include Meyerweb CSS reset and normalize.css.

2. Specificity

CSS specificity is a system used to determine which style rules should be applied when multiple rules target the same element. By increasing the specificity of your style rules, you can override the default user agent styles.

To increase specificity, you can use:

• Element tags: For example, div or table.
• Class names: For example, .table-custom.
• ID selectors: For example, #main-table.

The more specific a selector is, the higher its specificity and the more likely it is to override default styles.

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