CSS

Preview

1. What is the difference between an ID selector and a class selector in CSS?
2. How do you apply styles to an element that is only a child of another specific element?
3. What is the CSS box model, and how does it affect the layout of a webpage?
4. Can you explain the concept of specificity in CSS and how it affects the precedence of styles applied to elements?
5. How do you use CSS to create responsive designs that adapt to different screen sizes on various devices?

Explain

CSS (Cascading Style Sheets) is a style sheet language used to define the look and formatting of a website. CSS is responsible for setting the size, color, font, and style of website elements such as text, images, and video.

Here’s an example of how CSS works to change the look of an HTML element:

In HTML, you might have a paragraph element that looks like this:

If you want to make the text “Hello, World!” appear in bold, you can use CSS. Here’s how:

p {
font-weight: bold;
}

This CSS code targets the paragraph element (indicated by the “p” selector) and sets the font-weight property to bold. This means that all text within the paragraph element will now appear in a bold font.

Overall, CSS allows designers and developers to create visually engaging and aesthetically pleasing websites that are easy to navigate and use.

Keypoint

1. CSS stands for Cascading Style Sheets.
2. CSS allows developers to control the appearance of HTML elements on a web page.
3. CSS can be used to define colors, fonts, layout, and other visual aspects of a web page.
4. CSS consists of a set of rules, each consisting of a selector and declarations.
5. Selector targets specific HTML elements while declarations specify the visual properties of the targeted elements.
6. CSS properties can be inherited from parent elements to their child elements.
7. CSS can be applied to multiple web pages with the use of external style sheets.
8. CSS also has advanced features like animations, media queries, and responsive design that allow developers to create dynamic and interactive web pages.

Review

1. What is the difference between padding and margin in CSS?
   Answer: Padding is the space between the content and the border of an element, while margin is the space outside the border of an element.

2. How can you center an element horizontally and vertically using CSS?
   Answer: You can use the “display” property with the “flex” value for the parent element, along with “justify-content” and “align-items” properties set to “center”.

3. What is the difference between “px”, “em” and “rem” units in CSS?
   Answer: “px” is a fixed unit of measurement, while “em” and “rem” are relative units. “em” is relative to the font-size of the parent element, while “rem” is relative to the font-size of the root element.

4. How can you make an element responsive using CSS?
   Answer: You can use media queries to apply different styles to an element based on the screen size of the device. You can also use percentage or relative units for sizing and positioning.

5. How can you create a simple animation in CSS?
   Answer: You can use the “@keyframes” rule to define the animation and the “animation” property to apply it to an element. For example, “@keyframes slidein { from { transform: translateX(-100%); } to { transform: translateX(0); } }” and “animation: slidein 1s ease-in-out;”.