CSS Introduction

CSS: The Art of Styling Web Pages

Cascading Style Sheets (CSS) is a powerful language that allows you to control the appearance of your web pages. It’s used to change the font, size, color, and other visual properties of text, images, and other elements on a webpage. By using CSS, you can create consistent and visually appealing web pages that meet your design specifications.

The Basics of CSS

CSS is a language that’s written in a series of selectors and declarations. A selector identifies the element that you want to style, and a declaration specifies the style properties that you want to apply to that element.

For example, the following CSS code would change the font of all headings on a webpage to Arial:

h1, h2, h3 {
  font-family: Arial;
}

CSS Selectors

There are many different types of CSS selectors that you can use to target different elements on a webpage. Here are a few of the most common:

• Element selectors target elements based on their name. For example, the p selector targets all paragraph elements on a webpage.
• Class selectors target elements based on a class name that has been assigned to them. For example, the .btn selector targets all elements that have been assigned the btn class.
• ID selectors target elements based on a unique ID that has been assigned to them. For example, the #header selector targets the element that has been assigned the header ID.

CSS Declarations

CSS declarations specify the style properties that you want to apply to an element. Each declaration consists of a property name and a value. Here are a few of the most common CSS properties:

• color specifies the color of an element’s text.
• font-family specifies the font that is used for an element’s text.
• font-size specifies the size of an element’s text.
• background-color specifies the color of an element’s background.
• width specifies the width of an element.
• height specifies the height of an element.

CSS Units

CSS values can be specified using a variety of units, including:

• Pixels (px) are the most commonly used unit for specifying the size of elements.
• Percentage (%) are used to specify the size of elements relative to their parent element.
• Ems (em) are used to specify the size of elements relative to the font size of the parent element.
• Rems (rem) are used to specify the size of elements relative to the root font size of the webpage.

CSS Inheritance

CSS properties can be inherited from parent elements to child elements. This means that you can set a property on a parent element, and all of its child elements will inherit that property. For example, if you set the font-family property on a <div> element, all of the <p> elements inside that <div> element will inherit the same font family.

CSS Specificity

CSS specificity is a system that determines which CSS rules should be applied to an element when multiple rules are defined. The more specific a rule is, the higher its specificity. The following factors affect the specificity of a CSS rule:

• Inline styles have the highest specificity.
• ID selectors have higher specificity than class selectors.
• Class selectors have higher specificity than element selectors.
• Multiple selectors have higher specificity than single selectors.

Conclusion

CSS is a powerful language that can be used to create beautiful and consistent web pages. By understanding the basics of CSS, you can start to create your own custom styles for your web pages.