How do I center a div in a webpage using CSS?
To center a div in a webpage using CSS, you can use the following CSS code:

div {
  width: 50%; /* Set a fixed width for the div */
  margin: 0 auto; /* Center the div horizontally */
}

The width property sets the width of the div, while the margin property with values 0 auto centers the div horizontally. The 0 value sets the top and bottom margins to zero, while the auto value centers the div horizontally.
This div is only centered horizontally. How can I center it vertically as well?