Introduction

In this tutorial, we will learn how to modify the design of a WordPress site using custom CSS (Cascading Style Sheets). CSS is a styling language used to control the appearance of HTML elements on a webpage.

By the end of this tutorial, you will be able to:
* Understand the basics of CSS.
* Know how to add custom CSS to your WordPress site.
* Modify the design of your WordPress site using CSS.

Prerequisites: Basic knowledge of WordPress and HTML is helpful but not necessary.

Step-by-Step Guide

Understanding CSS

CSS is used to style the HTML elements of your webpage. It controls how your website appears on different devices. You can use it to set colors, fonts, layouts, and much more.

CSS rules consist of a selector and a declaration block. The selector points to the HTML element you want to style. The declaration block contains one or more declarations separated by semicolons. Each declaration includes a CSS property name and a value, separated by a colon.

selector {
    property: value;
    property: value;
}

Adding Custom CSS to WordPress

To add custom CSS to your WordPress site, follow these steps:
1. In the WordPress Admin Panel, go to Appearance > Customize.
2. In the Customizer, click on the Additional CSS tab.
3. In the Additional CSS section, you can write your custom CSS rules.

Remember to click the Publish button to save your changes.

Code Examples

Example 1: Changing The Background Color

Let's change the background color of our WordPress site to light blue.

body {
    background-color: lightblue;
}

Here, body is the selector which points to the whole body of the website. The property background-color changes the background color of the selected element.

Example 2: Changing The Font Size And Color

Let's change the font size and color of all paragraph (p) elements.

p {
    color: red;
    font-size: 20px;
}

In this example, p is the selector. The color property changes the text color and the font-size property changes the size of the text.

Summary

In this tutorial, we learned the basics of CSS and how to add custom CSS to a WordPress site. We also learned how to change the background color and the font size and color of text.

Next, you can learn about more complex CSS properties and how to use them to further customize your WordPress site. Consider exploring CSS frameworks like Bootstrap or learning about CSS preprocessors like Sass.

Additional resources:
* W3Schools CSS Tutorial
* Mozilla Developer Network (MDN) CSS Guide

Practice Exercises

Exercise 1: Change The Color Of All Headings To Green

Solution:

h1, h2, h3, h4, h5, h6 {
    color: green;
}

Exercise 2: Change The Font Family Of All Text To 'Arial'

Solution:

body {
    font-family: Arial;
}

Exercise 3: Set The Width Of Images To 500 Pixels

Solution:

img {
    width: 500px;
}

Remember, the best way to learn is by doing. So, try to modify the design of your WordPress site using the concepts you've learned in this tutorial. Happy coding!