Session 1: Your First Interactive Web Page

What You Will Build Today

A web page with a button that changes color and text when you click it. Simple, but it introduces the three core technologies of web development!

Setup

CodePen (Works in Browser!)

  1. Go to codepen.io
  2. Click Start Coding (no sign-up required!)
  3. You will see 3 panels: HTML, CSS, and JS

Accept Your GitHub Assignment

Click the link above to create your own GitHub repository for this course. You will use it to save your work.

Part 1: HTML - The Structure

HTML is like the skeleton of a web page. It defines what elements exist.

Step 1: Create the Basic Structure

In CodePen’s HTML panel, type this (or paste it):

<h1>Welcome to GameCraft!</h1>
<p>Click the button below:</p>
<button id="magicButton">Click Me!</button>

What Does This Mean?

  • <h1> - A big heading
  • <p> - A paragraph of text
  • <button> - A clickable button!
  • id="magicButton" - A name we’ll use later to control this button

Note: CodePen automatically adds the HTML structure tags (<!DOCTYPE html>, <html>, <head>, <body>) for you, so we only write what goes inside the body!

Test It!

The page updates automatically in CodePen! You should see a plain page with a heading, text, and a button.

Part 2: CSS - The Style

CSS is like clothes and makeup for your web page. It makes things look good!

Step 2: Add Style

In CodePen’s CSS panel, add this:

body {
    font-family: Arial, sans-serif;
    text-align: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 50px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

h1 {
    font-size: 48px;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

p {
    font-size: 20px;
    margin-bottom: 30px;
}

button {
    font-size: 24px;
    padding: 20px 40px;
    background-color: #ff6b6b;
    color: white;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 8px 15px rgba(0,0,0,0.3);
    transition: all 0.3s ease;
}

button:hover {
    background-color: #ee5a52;
    transform: translateY(-3px);
    box-shadow: 0 12px 20px rgba(0,0,0,0.4);
}

What Does This Do?

  • body { ... } - Styles the entire page (gradient background, centered content)
  • h1 { ... } - Makes the heading bigger and adds a shadow
  • button { ... } - Makes the button colorful, rounded, and adds a shadow
  • button:hover - Changes how the button looks when you move your mouse over it
  • transition - Makes changes smooth and animated

Test It!

The page updates automatically! Much better looking!

Part 3: JavaScript - The Interaction

JavaScript is the brain of your web page. It makes things DO stuff!

Step 3: Add Interactivity

In CodePen’s JS panel, add this:

// Step 1: Find the button on the page
const button = document.getElementById('magicButton');

// Step 2: Create a variable to count clicks
let clickCount = 0;

// Step 3: Define what happens when button is clicked
function handleClick() {
    // Increase the count
    clickCount = clickCount + 1;
    
    // Change the button text
    button.textContent = 'Clicked ' + clickCount + ' times!';
    
    // Change the button color randomly
    const randomColor = getRandomColor();
    button.style.backgroundColor = randomColor;
}

// Step 4: Create a function to generate random colors
function getRandomColor() {
    const colors = ['#ff6b6b', '#4ecdc4', '#45b7d1', '#f7b731', '#5f27cd', '#00d2d3'];
    const randomIndex = Math.floor(Math.random() * colors.length);
    return colors[randomIndex];
}

// Step 5: Tell the button to run handleClick when clicked
button.addEventListener('click', handleClick);

Let’s Break This Down

  1. const button = ... - Finds your button by its id and saves it in a variable
  2. let clickCount = 0 - Creates a counter starting at 0
  3. function handleClick() { ... } - A recipe for what to do when clicked
  4. clickCount = clickCount + 1 - Adds 1 to the counter (like tallying scores!)
  5. button.textContent = ... - Changes what the button says
  6. button.style.backgroundColor = ... - Changes the button’s color
  7. addEventListener('click', ...) - Says “when someone clicks, run this function”

Test It!

Click your button! It should:

  • Count your clicks
  • Change colors randomly
  • Update the text

Congratulations — you just made something interactive!

Part 4: Make It Your Own

Challenges:

  1. Easy: Change the starting button text to something fun
  2. Medium: Add more colors to the colors array
  3. Hard: Make the heading also change when you click the button

Hint for #3: You’ll need to get the heading with document.querySelector('h1') and change its text!

CodePen Tip: Click “Fork” at the top to save your own copy (requires a free account)

What You Learned Today

  • HTML - Structure (headings, paragraphs, buttons)
  • CSS - Styling (colors, sizes, effects)
  • JavaScript - Interactivity (variables, functions, events)
  • The Browser - How to run and test web pages
  • Three-part pattern - Structure → Style → Behavior

Next Session Preview

Session 2: We will switch to VS Code, set up GitHub, and build two real games - a Click Speed Challenge with timers and a Gem Catcher with canvas animation. Get ready to level up!

Homework (Optional)

  1. Change the gradient background colors (try different hex codes!)
  2. Add another button that does something different
  3. Share your page! (In CodePen, click “Save” then share the URL)

Common Issues

Problem: “I don’t see anything”
Solution: Make sure you’re on CodePen.io and clicked “Start Coding”

Problem: “The button doesn’t do anything”
Solution: Check that the button’s id="magicButton" matches what’s in the JavaScript

Problem: “My code has red underlines”
Solution: That’s okay! CodePen sometimes shows warnings that don’t affect functionality

Resources

← Back to GameCraft Home | Next: Session 2 - Click Speed and Gem Catcher →

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