CSS Foundations: Selectors, Cascade, Layout, and Standards

All flashcards

What is CSS?

CSS, or Cascading Style Sheets, is a language for specifying the presentation of markup documents, including their colors, fonts, spacing, and layout.

What are the parts of a basic CSS rule?

A CSS rule consists of a selector and a declaration block enclosed in braces. The block contains one or more declarations.

How do class and ID selectors differ?

A class selector begins with a dot and can match multiple elements. An ID selector begins with a hash and targets an element whose ID is intended to be unique within its document.

How do pseudo-classes differ from pseudo-elements?

Pseudo-classes select elements according to a state or other contextual information and use single-colon notation. Pseudo-elements select a part of an element and conventionally use double-colon notation.

Why use an external stylesheet?

An external stylesheet lets multiple pages share presentation rules, reduces repeated style definitions, makes site-wide changes easier, and may be cached by the browser.

Quiz questions

1. What is the primary purpose of CSS?Answer: To specify the presentation of a markup document.
2. Which part of a CSS rule identifies the elements to which the rule applies?Answer: The selector.
3. In `h1 { color: red; }`, what role does `red` play?Answer: It is the value of the `color` property.
4. Which selector targets elements with the class name `notice`?Answer: .notice
5. What does the selector `div .myClass` target?Answer: Elements with class `myClass` that are descendants of a `div`.