Initial, inherit, unset, and revert in CSS are four often overlooked but very useful keywords used to control style inheritance and reset. 1. initial will restore the attribute to the initial value defined by the specification, such as color will turn black; 2. inherit the element inherits the attribute value of the parent element, such as the child element's text color follows the parent; 3. unset is manifested as inherit or initial according to whether the attribute can be inherited, which is suitable for quickly clearing styles; 4. revert falls back the style to the browser or user default settings, which is often used to prevent style pollution. They are very useful in component development and style debugging.

CSS has four often overlooked but very useful keywords: initial , inherit , unset , and revert . They are used to control how styles are passed and applied between different elements, and understanding them can help you better manage CSS style inheritance and default value issues.

1. initial : restore to the default initial value of the property

initial keyword resets a CSS property to the initial value in its specification definition , rather than the value in the browser's default stylesheet.

For example:

 p {
  color: initial;
}

The above code will restore the color of the paragraph text to the browser default settings (usually black), and it will be useless even if you set the global font color elsewhere.

It should be noted that not all attributes are as intuitive . For example, display: initial will become inline on most elements, which may cause layout confusion.

Common uses: Clear all custom styles of a specific attribute and return to its original state.

2. inherit : inherit style from parent element

As the name implies, inherit will allow the current element to inherit the corresponding attribute value of its parent element.

For example:

 .child {
  color: inherit;
}

If the parent element text color of .child is red, then the text of .child will also turn red.

This is useful in some component designs, especially when you want the child components to "automatically" adapt to the parent style, such as the text color inside the button.

Not all attributes can be inherited (such as margin or padding ), but text-related attributes such as color and font-size are OK.

3. unset : Different processing is done according to whether the attribute can be inherited

unset is a "smart" keyword:

• If the property itself is inheritable (such as color ), it is equivalent to inherit
• If the attribute is not inherited (such as border ), it is equivalent to initial

Examples of usage scenarios:

 button {
  all: unset;
}

This quickly removes all default styles of the button while retaining some naturally inherited text styles.

Suitable for building "clean" UI components, such as custom buttons or input boxes.

4. revert : Restore to the settings of the user agent or user stylesheet

revert is more special, it means: "Restore to what it looks like if no style is set".

In simple terms, it is to undo your CSS modifications and let the browser decide how to display them .

for example:

 a {
  color: revert;
}

The link will be restored to the browser's default blue color (or user-defined style).

This term is often used in frameworks or libraries to prevent style contamination, especially when developing component libraries.

In general, these four keywords have their own uses and are often used in conjunction with them to achieve more flexible style control. For example, when writing component styles, use all: unset to quickly reset them, and then manually add the required styles; or use revert to fall back during debugging to see the native effect.

Basically that's it. If you use it too much, you will find that they are really convenient when resolving style conflicts and inheritance issues.

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