Bird
Raised Fist0
CSSmarkup~5 mins

Universal selector in CSS

Choose your learning style10 modes available
LearnWhyDeepRenderTryChallengeProjectRecallPerf

Start learning this pattern below

Jump into concepts and practice - no test required

or
Recommended
Test this pattern10 questions across easy, medium, and hard to know if this pattern is strong
Introduction

The universal selector helps you style all elements on a webpage at once. It saves time when you want a common style everywhere.

You want to set a common font or color for the entire page.
You want to remove default spacing or margins from all elements.
You want to apply a background color to every element.
You want to reset styles before adding your own.
You want to quickly test how a style looks on all elements.
Syntax
CSS
* { property: value; }
The asterisk (*) means 'all elements'.
Put the styles inside curly braces { }.
Examples
This removes all default margin and padding from every element.
CSS
* { margin: 0; padding: 0; }
This sets the font for all elements to Arial or a similar font.
CSS
* { font-family: Arial, sans-serif; }
This changes how width and height are calculated for all elements, making layouts easier.
CSS
* { box-sizing: border-box; }
Sample Program

This example uses the universal selector (*) to remove all default margin and padding, set a font, and add a light background color to every element. Then it adds some spacing and colors to specific elements.

CSS
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <title>Universal Selector Example</title>
  <style>
    * {
      margin: 0;
      padding: 0;
      font-family: Arial, sans-serif;
      background-color: #f0f8ff;
    }
    body {
      padding: 1rem;
    }
    h1 {
      color: #333;
      margin-bottom: 1rem;
    }
    p {
      color: #555;
    }
  </style>
</head>
<body>
  <h1>Welcome!</h1>
  <p>This page uses the universal selector to style all elements.</p>
</body>
</html>
OutputSuccess
Important Notes

The universal selector can slow down your page if overused with complex styles.

It applies to every element, so be careful when combining it with other selectors.

Use it mainly for simple, broad styles like resets or fonts.

Summary

The universal selector (*) targets all elements on the page.

It is useful for setting common styles like margin, padding, and fonts.

Use it wisely to avoid unexpected style changes or performance issues.

Practice

(1/5)
1. What does the CSS universal selector * do?
easy
A. Selects elements with a specific class
B. Selects only div elements
C. Selects all elements on the page
D. Selects elements with a specific ID

Solution

  1. Step 1: Understand the universal selector symbol

    The * symbol in CSS means "all elements" without exception.

  2. Step 2: Apply the selector meaning

    Using * targets every element on the page, regardless of tag, class, or ID.

  3. Final Answer:

    Selects all elements on the page -> Option C

  4. Quick Check:

    Universal selector = all elements [OK]
Hint: Remember * means every element on the page [OK]
Common Mistakes:
  • Thinking * selects only specific tags
  • Confusing * with class or ID selectors
  • Assuming * targets only visible elements
2. Which of the following is the correct syntax to apply a margin of 0 to all elements using the universal selector?
easy
A. # * { margin: 0; }
B. . * { margin: 0; }
C. all { margin: 0; }
D. * { margin: 0; }

Solution

  1. Step 1: Identify the universal selector syntax

    The universal selector is just * without any prefix like dot or hash.

  2. Step 2: Check the CSS rule format

    The correct CSS rule to apply margin 0 to all elements is * { margin: 0; }.

  3. Final Answer:

    * { margin: 0; } -> Option D

  4. Quick Check:

    Universal selector syntax = * { ... } [OK]
Hint: Universal selector is just * without dot or hash [OK]
Common Mistakes:
  • Adding dot or hash before *
  • Using invalid selector names like 'all'
  • Forgetting curly braces
3. Given this CSS code:
* { padding: 10px; }
p { padding: 5px; }

What will be the padding of a paragraph (<p>) element?
medium
A. 10px
B. 5px
C. 15px
D. 0px

Solution

  1. Step 1: Understand selector specificity

    The universal selector * applies padding 10px to all elements, but the p selector is more specific.

  2. Step 2: Apply CSS specificity rules

    Since p selector is more specific than *, the paragraph's padding will be 5px, overriding the universal selector.

  3. Final Answer:

    5px -> Option B

  4. Quick Check:

    More specific selector wins = 5px [OK]
Hint: More specific selector overrides * [OK]
Common Mistakes:
  • Assuming * always overrides other selectors
  • Adding padding values instead of overriding
  • Ignoring CSS specificity rules
4. You wrote this CSS:
* { font-size: 16px }

But the browser ignores it and uses default font sizes. What is the likely error?
medium
A. CSS file not linked properly
B. Universal selector cannot set font size
C. Font size must be in quotes
D. Missing semicolon after 16px

Solution

  1. Step 1: Check CSS syntax

    The CSS rule * { font-size: 16px } is syntactically valid; a trailing semicolon is optional at the end of a rule.

  2. Step 2: Understand common issues

    If valid CSS is ignored by the browser, the stylesheet is likely not linked properly in the HTML with a <link rel="stylesheet" href="..."> tag.

  3. Final Answer:

    CSS file not linked properly -> Option A

  4. Quick Check:

    No styles applied? Check <link> tag [OK]
Hint: If * styles not applying, verify CSS file link [OK]
Common Mistakes:
  • Thinking universal selector can't style fonts
  • Using quotes around numeric values
  • Ignoring CSS file linking issues
5. You want to reset margin and padding for all elements but keep links (<a>) with no margin and 5px padding. Which CSS achieves this?
hard
A. * { margin: 0; padding: 0; } a { padding: 5px; }
B. a { margin: 10px; padding: 5px; } * { margin: 0; padding: 0; }
C. * { margin: 0; padding: 5px; } a { margin: 0; padding: 0; }
D. * { margin: 0; padding: 0; a { padding: 5px; } }

Solution

  1. Step 1: Reset all elements margin and padding

    The universal selector * { margin: 0; padding: 0; } sets margin and padding to zero for all elements.

  2. Step 2: Override padding for links

    The selector a { padding: 5px; } specifically sets padding to 5px for all <a> elements, overriding the universal selector.

  3. Final Answer:

    * { margin: 0; padding: 0; } a { padding: 5px; } -> Option A

  4. Quick Check:

    Specific selector overrides universal [OK]
Hint: Use * first, then override with specific selector [OK]
Common Mistakes:
  • Placing universal selector after specific selector
  • Nesting selectors incorrectly
  • Setting wrong padding values