This site is mobile accessible. Press the "Tap Here" button to use a smaller font-size. Tap Here!

Smartphone icons created by Freepik - Flaticon

1.3 CSS Selectors

CSS selectors are used to "find" (or select) the HTML elements you want to style. We can divide CSS selectors into five categories:

• Simple selectors (select elements based on name, id, class)
• Combinator selectors (select elements based on a specific relationship between them)
• Pseudo-class selectors (select elements based on a certain state)
• Pseudo-elements selectors (select and style a part of an element)
• Attribute selectors (select elements based on an attribute or attribute value)

The CSS element Selector

The element selector selects HTML elements based on the element name.

Example 1: CSS element Selector

Here, all <p> elements on the page will be center-aligned, with a red text color:

p {
  text-align: center;
  color: red;
}

The CSS id Selector

The id selector uses the id attribute of an HTML element to select a specific element. The id of an element is unique within a page, so the id selector is used to select one unique element! To select an element with a specific id, write a hash (#) character, followed by the id of the element.

Example 2: CSS id Selector

The CSS rule below will be applied to the HTML element with id="para1":

#para1 {
  text-align: center;
  color: red;
}

Note: An id name cannot start with a number!

The CSS class Selector

The class selector selects HTML elements with a specific class attribute. To select elements with a specific class, write a period (.) character, followed by the class name.

Example 3: CSS class Selector part 1

In this example all HTML elements with class="center" will be red and center-aligned:

.center {
  text-align: center;
  color: red;
}

You can also specify that only specific HTML elements should be affected by a class.

Example 4: CSS class Selector part 2

In this example only <p> elements with class="center" will be red and center-aligned:

p.center {
  text-align: center;
  color: red;
}

HTML elements can also refer to more than one class.

Example 5: CSS class Selector part 3

In this example the <p> element will be styled according to class="center" and to class="large":

<p class="center large">This paragraph refers to 
two classes.</p>

Note: A class name cannot start with a number!

The CSS Universal Selector

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

Example 6: CSS Universal Selector

The CSS rule below will affect every HTML element on the page:

* {
  text-align: center;
  color: blue;
}

The CSS Grouping Selector

The grouping selector selects all the HTML elements with the same style definitions. Look at the following CSS code (the h1, h2, and p elements have the same style definitions):

h1 {
  text-align: center;
  color: red;
}

h2 {
  text-align: center;
  color: red;
}

p {
  text-align: center;
  color: red;
}

It will be better to group the selectors, to minimize the code. To group selectors, separate each selector with a comma.

Example 7: CSS Grouping Selector

In this example we have grouped the selectors from the code above:

h1, h2, p {
  text-align: center;
  color: red;
}

All CSS Simple Selectors