By Dhanian - CodeWithDhanian

Grab my coding ebooks & resources → http://codewithdhanian.gumroad.com

What is CSS?

CSS stands for Cascading Style Sheets. It is used to style and design websites, making them visually appealing. While HTML gives a webpage structure, CSS adds beauty, color, layout, and responsiveness.

Why Learn CSS?

  • Build beautiful websites
  • Customize layouts
  • Make websites responsive
  • Add animations & transitions
  • Control every visual aspect of a webpage

1. CSS Syntax Overview 

selector {
  property: value;
}

Example:

body {
  background-color: #ffffff;
  color: #000000;
}

2. Types of CSS

Inline CSS 

style="color:blue;">Hello World

Internal CSS 

h1 { color: green; }

External CSS 

rel="stylesheet" href="style.css">

3. CSS Selectors Mastery

Selector Example Meaning
Universal * { } Targets everything
Element p { } Targets

tags
Class .box { } Targets class="box"
ID #header { } Targets id="header"
Group h1, h2, p { } Targets multiple elements
Descendant div p { } Targets

inside

4. Colors in CSS 

color: red;
color: #ff0000;
color: rgb(255, 0, 0);
color: hsl(0, 100%, 50%);

5. Text Styling 

p {
  font-size: 18px;
  font-family: 'Arial', sans-serif;
  font-weight: bold;
  text-align: justify;
  text-decoration: underline;
  text-transform: uppercase;
  line-height: 1.5;
}

6. The CSS Box Model

  • Content
  • Padding
  • Border
  • Margin

Example:

.card {
  padding: 20px;
  border: 2px solid black;
  margin: 15px;
}

7. Units in CSS

  • px (pixels)
  • % (percentage)
  • em (relative to parent)
  • rem (relative to root)
  • vw / vh (viewport width/height)
  • fr (fraction for grid)

8. Display Property 

div {
  display: block;
}
span {
  display: inline;
}
.box {
  display: inline-block;
}
.container {
  display: flex;
}
.grid-container {
  display: grid;
}

9. Flexbox Complete Guide 

.container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

10. CSS Grid Layout 

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 15px;
}

11. Position Property 

.box {
  position: relative;
  top: 10px;
  left: 20px;
}

Types:

  • static
  • relative
  • absolute
  • fixed
  • sticky

12. Media Queries for Responsive Design 

@media (max-width: 768px) {
  body {
    background-color: lightblue;
  }
}

13. Pseudo-Classes & Pseudo-Elements 

a:hover { color: red; }
input:focus { border: 2px solid green; }
p::first-letter { font-size: 200%; }

14. CSS Variables 

:root {
  --primary-color: #3498db;
}

h1 {
  color: var(--primary-color);
}

15. Animations & Transitions

Transitions 

.button {
  background: blue;
  transition: background 0.3s ease;
}
.button:hover {
  background: darkblue;
}

Animations 

@keyframes slide {
  from { transform: translateX(0); }
  to { transform: translateX(100px); }
}

.box {
  animation: slide 2s infinite alternate;
}

16. Shadows in CSS 

.box {
  box-shadow: 2px 2px 10px rgba(0,0,0,0.2);
  text-shadow: 1px 1px 5px black;
}

17. CSS Best Practices

  • Use External CSS
  • Use Semantic HTML + CSS
  • Use CSS Variables
  • Mobile-first design
  • Keep your code DRY (Don’t Repeat Yourself)
  • Use comments for clarity

18. CSS Resources to Learn More

Final Thoughts

CSS is fun and powerful once you understand the core concepts. This 2-minute guide gives you a strong foundation to start building real-world projects.

Ready to go deeper?

Download my ebooks, guides, and coding resources here → http://codewithdhanian.gumroad.com