In CSS, "initial value" refers to the default value a property takes when no styles are applied or inherited. 1. It is defined by the CSS specification for each property. 2. Examples include margin: 0, padding: 0, and color: #000. 3. Not all properties are inherited, so non-inherited properties without specified values revert to their initial values. 4. Developers often use resets or normalize.css to ensure consistency across browsers. 5. The initial keyword can manually reset a property to its default state, though it may have unintended effects. 6. Knowing initial values helps debug layouts and maintain consistent styling across projects.
When a CSS property hasn't been explicitly set, it takes on an initial value defined by the CSS specification. Each property has its own default state, and understanding these defaults can help avoid confusion when styling elements.

What does "initial value" mean in CSS?
The initial value of a CSS property is the default value that a property takes if no other styles are applied or inherited from parent elements. This value is defined in the CSS specification for each individual property. For example, the margin
property has an initial value of 0
, while color
starts with a value that depends on the user agent (typically black).
It's important to note that not all properties are inherited. If a child element doesn’t have a specified value and the property isn’t inherited, it will fall back to the initial value rather than taking it from a parent.

Common CSS properties and their initial values
Here are some frequently used properties and what they start as:
-
margin
:0
-
padding
:0
-
color
: usually black (#000
) -
font-size
:medium
-
display
:inline
-
position
:static
-
width
:auto
-
height
:auto
These defaults vary between browsers slightly, which is why many developers use resets or normalize.css to create a consistent baseline across different environments.

How to check or reset to initial values
If you're troubleshooting unexpected layout behavior, it might be due to the browser’s default styling. You can inspect elements using developer tools to see what styles are being applied.
To manually reset a property to its original default, you can use the initial
keyword like this:
margin: initial;
This will reset that specific property to whatever the browser considers the starting point.
Keep in mind: Using
initial
can sometimes reset more than intended, especially if you’re not aware of how a particular property behaves by default.
Why initial values matter in real-world styling
Knowing the default states helps when debugging layouts or trying to understand why certain elements appear differently without any custom CSS. For instance, headings (h1
, h2
, etc.) have built-in margins and font sizes in most browsers. If you don’t override them, your design might look inconsistent across sites.
Also, setting properties explicitly—even if they match the initial value—can improve code readability and prevent issues when other stylesheets or frameworks come into play.
Understanding the basics of initial values gives you better control over your layout and styling decisions. It may seem minor, but it’s one of those things that makes CSS easier to manage long-term.
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