30+ Top CSS Interview Questions & Answers You Should Know In 2024

Coursesity Team -

Are you gearing up for a CSS interview? If so, mastering the fundamentals is only half the battle. If you want to impress employers, you will still have to learn how to tackle complex problems like responsive design, layouts, and advanced selectors. In this guide, you will find more than 30 questions and answers related to CSS that will assist you in making a great impression during an interview. Ready to ace it? Let’s get started!

1. What is CSS?

CSS (Cascading Style Sheet) is a style sheet language that defines how elements and content on a webpage are displayed. It is used alongside HTML to design and style websites. In addition to HTML, CSS is also supported by other markup languages such as plain XML, SVG, and XUL.

2. What are the different variations of CSS?

Here are the different CSS variations:

  • CSS1
  • CSS2
  • CSS2.1
  • CSS3
  • CSS4

3. What are the advantages of CSS?

Some of the advantages of using CSS include:

  • Site-wide consistency
  • Page reformatting
  • Separation of content from presentation
  • Accessibility improvements
  • Reduced bandwidth usage

4. What are the limitations of CSS?

Some limitations of CSS are:

  • Difficulty in targeting specific text elements.
  • Lack of column declaration.
  • Pseudo-classes not controlled by dynamic behavior.
  • Inability to ascend by selectors.
  • Limited vertical control.
  • No expressions support.

5. Why are background and color separate properties if they should always be set together?

The reasons are:

  • Color is an inherited property, while the background is not, which could lead to confusion.
  • Keeping them separate enhances the legibility of style sheets. Combining background properties with color would increase complexity.

6. What are CSS frameworks?

CSS frameworks are pre-planned libraries that simplify web page styling and ensure compliance with standards. Some frequently used CSS frameworks are:

  • Bootstrap
  • Ulkit
  • Foundation
  • Semantic UI
  • Gumby

7. What is the Box model in CSS? What CSS properties are a part of it?

The box model in CSS is used to determine the height and width of an element, considering the following properties:

  • Content: Where text or images are placed.
  • Padding: Space surrounding the content.
  • Border: Surrounds the padding.
  • Margin: Surrounds the border.

8. How to include CSS in a webpage?

CSS can be included in a webpage in several ways:

  • External Style Sheet: Linked to your HTML document using the <link> tag.
  • Embedded CSS: Included within your HTML page using the <style> tag.
  • Inline Styles: Applied directly to HTML elements using the style attribute.
  • Importing Stylesheets: Adding CSS using the @import rule.

9. Name the four types of @media properties.

The four types of @media properties are:

  • All: Default property, used for all media types.
  • Screen: Used for computer and mobile screens.
  • Print: Used for printers.
  • Speech: Used for screen readers.

10. What are the advantages of Embedded Style Sheets?

Advantages include:

  • The ability to create classes for use on multiple tag types.
  • The use of grouping methods and selectors to apply styles in complex situations.
  • No additional download required for importing the information.

11. What exactly is the difference between inline, inline-block, and block elements?

  • Inline Elements: Do not begin on a new line and appear on the same line as other content and tags. Examples include <a>, <span>, and <img>.
  • Inline-Block Elements: Behave like inline elements but can have width and height set.
  • Block Elements: Always start on a new line, taking up the full width available. Examples include <div> and <p>.

12. Explain the CSS position property.

  • Absolute: Place an element exactly where you want it, relative to its nearest positioned ancestor.
  • Relative: Positions the element relative to its normal position, allowing for z-index and absolute positioning of child elements.
  • Fixed: Positions the element relative to the browser window, so it remains in the same position when scrolling.
  • Static: The default positioning, where elements are placed according to the normal document flow.
  • Sticky: The element toggles between relative and fixed positioning, depending on the scroll position.

13. What is a CSS selector?

A CSS selector means the relation in a string to point out to which element the rule applies to. The selector connects the Web page with the style sheet.CSS selectors come in various forms:

  • CSS Id Selector
  • CSS Universal Selector
  • CSS Element Selector
  • CSS Group Selector

14. What does the :root pseudo-class refer to in CSS?

The :root pseudo-class refers to the highest-level parent element in the document tree, or DOM. It is defined in Selectors Level 3.

15. Explain the difference between CSS Grid and Flexbox.

  • CSS Grid: It is a two-dimensional layout system for controlling both columns and rows; its configuration can be very complex.
  • CSS Flexbox: A one-dimensional layout scheme that helps to organize elements in both a row or column meticulously.

16. List some CSS-style components.

The components of CSS styles include:

  • Value
  • Property
  • Selector

17. How do logical tags differ from physical tags?

  • Logical Tags: Do not affect visual appearances but convey meaning or structure (e.g., <em>, <strong>).
  • Physical Tags: Affect the appearance of the text (e.g., <b>, <i>).

18. How to restore the default property value with CSS?

To restore the default property value in CSS, use the initial keyword, which resets the CSS values to their defaults instead of the browser’s default styles.

19. What is Tweening?

Tweening can be defined as creating frames in between two images such that they appear to blend for a smooth transition. In CSS3, we can perform Tweening using the transform module.

20. What is RWD?

RWD basically stands for Responsive Web Design. Explained in simpler words, it is described as an approach that makes sure that the appearance of any webpage is presented well on any screen size of any device like mobiles, tabs, desktops, laptops, etc.

21. What is the use of CSS Opacity?

CSS Opacity: Opacity defines an amount of the element's transparency With changing the opacity, either you can make an element transparent, or not; you can further use it in an overlay, hover effect, or a background image implementation.

22. What is the difference between class selectors and ID selectors?

  • Class Selectors: Class selectors are denoted by a period. On a page, it is possible to apply class selectors to multiple elements.
  • ID Selectors: Represented by a hash (#), ID selectors are unique and should be applied to only one element per page. Example: #idname.

23. What is the difference between inline, embedded, and external style sheets?

  • Inline Style Sheets: These would apply styles literally within an HTML element by using the style attribute.
  • Embedded Style Sheets: These are written in the <style> tag included in the <head> section of the HTML document.
  • External Style Sheets: Attached to the HTML document with the <link> tag, they make styles for many pages.

24. What are the benefits of CSS sprites?

CSS Sprites One image file for multiple images will reduce HTTP requests; thus improving load times. By using background positioning, specific portions of the sprite can be displayed as needed.

25. What is the float property of CSS?

The float property allows elements to float to the left or right of their container, with surrounding text and inline elements wrapping around them. It’s often used for creating layouts with sidebars or image text wrapping.

26. Explain the difference between visibility: hidden and display: none.

  • visibility: hidden: The element is invisible, but still occupies space in the layout.
  • display: none: It completely removes the element from the flow of the document without taking any space for that element.

27. What is the difference between CSS2 and CSS3?

  • CSS2: Laid the basic platform for selectors, positioning of elements, and media types.
  • CSS3: Improved version of CSS2 with inclusion of new modules on Flexbox, Grid, Animations, Transitions, and even improved Media Queries.

28. What is VH/VW in CSS?

VH and VW are also CSS units that refer to the Viewport Height and Viewport Width correspondingly. Both are relative units in CSS and correspond to a percentage of the viewport height and width. 1 VH would be the keyword to set the 1% height for the viewport, and so is 1 VW.

29. What is the difference between a class and an ID?

  • Class: helps in styling several elements with one class name. It’s defined with a . in CSS.
  • ID: Used to style a single, unique element. It’s defined with a # in CSS.

30. What is a CSS Preprocessor?

CSS Preprocessor is a scripting language that enriches the capacity of CSS and ultimately compiles the code into regular CSS syntax. For example, the functionalities of Pre-Processors are SASS, LESS, and STYLUS.

31. What are Pseudo-classes?

Pseudo-classes are words that are used in a selector and describe a special state of the element selected. For instance, :hover applies a style when a mouse is hovering over an element.

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