fix: align HTML lesson task instructions with solution code

Update task instructions to explicitly specify all content that appears
in the solution, so students can complete lessons without guessing:

- semantic-containers: specify "My Website", "Welcome to my site!", "Copyright 2025"
- form-structure: specify label text "Name:" and attribute values
- input-types: specify label texts "Email:" and "Password:"
- input-constraints: specify placeholder text "Enter password"

lessons/20-html-elements.json

@@ -34,7 +34,7 @@
 			"id": "semantic-containers",
 			"title": "Semantic Container Elements",
 			"description": "Modern HTML uses semantic containers that describe their content:<br><br><kbd>&lt;header&gt;</kbd> - Page or section header<br><kbd>&lt;nav&gt;</kbd> - Navigation links<br><kbd>&lt;main&gt;</kbd> - Main content area<br><kbd>&lt;section&gt;</kbd> - Thematic grouping<br><kbd>&lt;article&gt;</kbd> - Self-contained content<br><kbd>&lt;footer&gt;</kbd> - Page or section footer",
-			"task": "Create a basic page structure with <kbd>&lt;header&gt;</kbd>, <kbd>&lt;main&gt;</kbd>, and <kbd>&lt;footer&gt;</kbd> elements. Add a heading in the header.",
+			"task": "Create a basic page structure:<br>1. Add a <kbd>&lt;header&gt;</kbd> with an <kbd>&lt;h1&gt;</kbd> containing the text 'My Website'<br>2. Add a <kbd>&lt;main&gt;</kbd> element with a paragraph saying 'Welcome to my site!'<br>3. Add a <kbd>&lt;footer&gt;</kbd> with a paragraph saying 'Copyright 2025'",
 			"previewHTML": "",
 			"previewBaseCSS": "body { font-family: system-ui; margin: 0; } header { background: #1976d2; color: white; padding: 15px; } main { padding: 20px; min-height: 100px; } footer { background: #424242; color: white; padding: 10px; text-align: center; }",
 			"sandboxCSS": "",

lessons/21-html-forms-basic.json

@@ -10,7 +10,7 @@
 			"id": "form-structure",
 			"title": "Form Structure",
 			"description": "Every form needs a <kbd>&lt;form&gt;</kbd> wrapper. Inside, use <kbd>&lt;label&gt;</kbd> to describe inputs and <kbd>&lt;input&gt;</kbd> for user data entry.<br><br>The <kbd>for</kbd> attribute on labels should match the <kbd>id</kbd> on inputs for accessibility.",
-			"task": "Create a form with a text input for 'Name'. Include a label connected to the input using for/id attributes.",
+			"task": "Create a form with:<br>1. A <kbd>&lt;label&gt;</kbd> with the text 'Name:' and <kbd>for=\"name\"</kbd> attribute<br>2. A text <kbd>&lt;input&gt;</kbd> with <kbd>id=\"name\"</kbd> and <kbd>name=\"name\"</kbd> attributes",
 			"previewHTML": "",
 			"previewBaseCSS": "body { font-family: system-ui; padding: 20px; } form { max-width: 300px; } label { display: block; margin-bottom: 5px; font-weight: 500; } input { width: 100%; padding: 8px; border: 1px solid #ccc; border-radius: 4px; box-sizing: border-box; }",
 			"sandboxCSS": "",
@@ -49,7 +49,7 @@
 			"id": "input-types",
 			"title": "Input Types",
 			"description": "Different input types provide appropriate keyboards and validation:<br><br><kbd>type=\"text\"</kbd> - General text<br><kbd>type=\"email\"</kbd> - Email with @ validation<br><kbd>type=\"password\"</kbd> - Hidden characters<br><kbd>type=\"number\"</kbd> - Numeric keyboard<br><kbd>type=\"tel\"</kbd> - Phone keyboard",
-			"task": "Create a login form with an email input and a password input, each with proper labels.",
+			"task": "Create a login form with two fields:<br>1. An email field: <kbd>&lt;label for=\"email\"&gt;Email:&lt;/label&gt;</kbd> and <kbd>&lt;input type=\"email\" id=\"email\"&gt;</kbd><br>2. A password field: <kbd>&lt;label for=\"password\"&gt;Password:&lt;/label&gt;</kbd> and <kbd>&lt;input type=\"password\" id=\"password\"&gt;</kbd><br><br>Optionally wrap each in a <kbd>&lt;div class=\"form-group\"&gt;</kbd> for spacing.",
 			"previewHTML": "",
 			"previewBaseCSS": "body { font-family: system-ui; padding: 20px; } form { max-width: 300px; } .form-group { margin-bottom: 15px; } label { display: block; margin-bottom: 5px; } input { width: 100%; padding: 8px; border: 1px solid #ccc; border-radius: 4px; box-sizing: border-box; }",
 			"sandboxCSS": "",

lessons/22-html-forms-validation.json

@@ -34,7 +34,7 @@
 			"id": "input-constraints",
 			"title": "Input Constraints",
 			"description": "Control what users can enter:<br><br><kbd>minlength</kbd> / <kbd>maxlength</kbd> - Text length limits<br><kbd>min</kbd> / <kbd>max</kbd> - Number range<br><kbd>pattern</kbd> - Regex pattern matching<br><kbd>placeholder</kbd> - Hint text (not a label!)",
-			"task": "Add validation: password must be 8-20 characters. Add a helpful placeholder.",
+			"task": "Add validation to the password input:<br>1. Add <kbd>minlength=\"8\"</kbd> for minimum length<br>2. Add <kbd>maxlength=\"20\"</kbd> for maximum length<br>3. Add <kbd>placeholder=\"Enter password\"</kbd> as a hint",
 			"previewHTML": "",
 			"previewBaseCSS": "body { font-family: system-ui; padding: 20px; } form { max-width: 350px; } .form-group { margin-bottom: 15px; } label { display: block; margin-bottom: 5px; } input { width: 100%; padding: 8px; border: 1px solid #ccc; border-radius: 4px; box-sizing: border-box; } input:invalid:not(:placeholder-shown) { border-color: #d32f2f; } .hint { font-size: 12px; color: #666; margin-top: 4px; } button { padding: 10px 20px; background: #1976d2; color: white; border: none; border-radius: 4px; cursor: pointer; }",
 			"sandboxCSS": "",