{
	"$schema": "../schemas/code-crispies-module-schema.json",
	"id": "box-model",
	"title": "CSS Box Model",
	"description": "Master the fundamental principles of space management in web design through the CSS box model. This module explores how content, padding, borders, and margins combine to create layout structures that are both visually appealing and structurally sound.",
	"difficulty": "beginner",
	"lessons": [
		{
			"id": "box-model-1",
			"title": "Padding",
			"description": "Every element in CSS is a box with four layers: content, padding, border, and margin. <strong>Padding</strong> creates breathing room between your content and the box's edge.<br><br>Without padding, text presses against borders awkwardly. Padding makes content readable and visually balanced.<br><br><pre>.card {\n  padding: 1rem;\n}</pre>",
			"task": "This profile card looks cramped. Add <kbd>padding: 1rem</kbd> to <kbd>.card</kbd> so the text has room to breathe.",
			"previewHTML": "<article class=\"card\"><h3>Sarah Chen</h3><p>Frontend Developer</p></article>",
			"previewBaseCSS": "body { font-family: system-ui, sans-serif; padding: 1rem; background: #f5f5f5; } .card { background: white; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); } .card h3 { margin: 0 0 4px; } .card p { margin: 0; color: #666; }",
			"sandboxCSS": "",
			"codePrefix": ".card {\n  ",
			"initialCode": "",
			"codeSuffix": "\n}",
			"solution": "padding: 1rem;",
			"previewContainer": "preview-area",
			"validations": [
				{
					"type": "property_value",
					"value": { "property": "padding", "expected": "1rem" },
					"message": "Set <kbd>padding: 1rem</kbd>"
				}
			]
		},
		{
			"id": "box-model-2",
			"title": "Borders",
			"description": "Borders create visual boundaries around elements. The <kbd>border</kbd> shorthand takes three values: width, style, and color.<br><br>Common styles: <kbd>solid</kbd>, <kbd>dashed</kbd>, <kbd>dotted</kbd>, <kbd>none</kbd>",
			"task": "Add a subtle left accent to the card with <kbd>border-left: 4px solid steelblue</kbd>.",
			"previewHTML": "<article class=\"card\"><h3>Sarah Chen</h3><p>Frontend Developer</p></article>",
			"previewBaseCSS": "body { font-family: system-ui, sans-serif; padding: 1rem; background: #f5f5f5; } .card { background: white; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); padding: 1rem; } .card h3 { margin: 0 0 4px; } .card p { margin: 0; color: #666; }",
			"sandboxCSS": "",
			"codePrefix": ".card {\n  ",
			"initialCode": "",
			"codeSuffix": "\n}",
			"solution": "border-left: 4px solid steelblue;",
			"previewContainer": "preview-area",
			"validations": [
				{
					"type": "regex",
					"value": "border-left:\\s*4px\\s+solid\\s+steelblue",
					"message": "Set <kbd>border-left: 4px solid steelblue</kbd>",
					"options": { "caseSensitive": false }
				}
			]
		},
		{
			"id": "box-model-3",
			"title": "Margins",
			"description": "Margins create space <em>outside</em> the element, separating it from neighbors. While padding pushes content inward, margins push other elements away.",
			"task": "Add space between these two profile cards with <kbd>margin-bottom: 1rem</kbd> on <kbd>.card</kbd>.",
			"previewHTML": "<article class=\"card\"><h3>Sarah Chen</h3><p>Frontend Developer</p></article><article class=\"card\"><h3>Alex Rivera</h3><p>UX Designer</p></article>",
			"previewBaseCSS": "body { font-family: system-ui, sans-serif; padding: 1rem; background: #f5f5f5; } .card { background: white; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); padding: 1rem; border-left: 4px solid steelblue; } .card h3 { margin: 0 0 4px; } .card p { margin: 0; color: #666; }",
			"sandboxCSS": "",
			"codePrefix": ".card {\n  ",
			"initialCode": "",
			"codeSuffix": "\n}",
			"solution": "margin-bottom: 1rem;",
			"previewContainer": "preview-area",
			"validations": [
				{
					"type": "property_value",
					"value": { "property": "margin-bottom", "expected": "1rem" },
					"message": "Set <kbd>margin-bottom: 1rem</kbd>"
				}
			]
		},
		{
			"id": "box-model-4",
			"title": "Box Sizing",
			"description": "By default, <kbd>width</kbd> only sets the content width. Padding and borders add to the total. This causes layout headaches.<br><br><kbd>box-sizing: border-box</kbd> includes padding and border in the width, making sizing predictable. Most developers apply this to all elements.",
			"task": "Both cards have <kbd>width: 200px</kbd>. The left uses default sizing (content-box), making it wider than expected. Fix the right card with <kbd>box-sizing: border-box</kbd>.",
			"previewHTML": "<div class=\"demo\"><article class=\"card\">Content-box</article><article class=\"card fix\">Border-box</article></div>",
			"previewBaseCSS": "body { font-family: system-ui, sans-serif; padding: 1rem; background: #f5f5f5; } .demo { display: flex; gap: 1rem; } .card { width: 200px; padding: 1rem; border: 4px solid steelblue; background: white; border-radius: 8px; }",
			"sandboxCSS": "",
			"codePrefix": ".fix {\n  ",
			"initialCode": "",
			"codeSuffix": "\n}",
			"solution": "box-sizing: border-box;",
			"previewContainer": "preview-area",
			"validations": [
				{
					"type": "property_value",
					"value": { "property": "box-sizing", "expected": "border-box" },
					"message": "Set <kbd>box-sizing: border-box</kbd>"
				}
			]
		},
		{
			"id": "box-model-5",
			"title": "Padding Shorthand",
			"description": "Padding accepts 1-4 values:<br>• 1 value: all sides<br>• 2 values: vertical | horizontal<br>• 4 values: top | right | bottom | left",
			"task": "This button needs more horizontal space than vertical. Set <kbd>padding: 8px 1rem</kbd> (8px top/bottom, 1rem left/right).",
			"previewHTML": "<button class=\"btn\">Follow</button>",
			"previewBaseCSS": "body { font-family: system-ui, sans-serif; padding: 1rem; } .btn { background: steelblue; color: white; border: none; border-radius: 4px; cursor: pointer; font-size: 1rem; }",
			"sandboxCSS": "",
			"codePrefix": ".btn {\n  ",
			"initialCode": "",
			"codeSuffix": "\n}",
			"solution": "padding: 8px 1rem;",
			"previewContainer": "preview-area",
			"validations": [
				{
					"type": "regex",
					"value": "padding:\\s*8px\\s+1rem",
					"message": "Set <kbd>padding: 8px 1rem</kbd>",
					"options": { "caseSensitive": false }
				}
			]
		},
		{
			"id": "box-model-6",
			"title": "Margin Shorthand",
			"description": "Margin uses the same shorthand pattern as padding. A common pattern is centering block elements horizontally with <kbd>margin: 0 auto</kbd>.",
			"task": "Center this card horizontally. Set <kbd>margin: 0 auto</kbd> to auto-calculate equal left/right margins.",
			"previewHTML": "<article class=\"card\"><h3>Sarah Chen</h3><p>Frontend Developer</p></article>",
			"previewBaseCSS": "body { font-family: system-ui, sans-serif; padding: 1rem; background: #f5f5f5; } .card { width: 250px; background: white; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); padding: 1rem; border-left: 4px solid steelblue; } .card h3 { margin: 0 0 4px; } .card p { margin: 0; color: #666; }",
			"sandboxCSS": "",
			"codePrefix": ".card {\n  ",
			"initialCode": "",
			"codeSuffix": "\n}",
			"solution": "margin: 0 auto;",
			"previewContainer": "preview-area",
			"validations": [
				{
					"type": "regex",
					"value": "margin:\\s*0\\s+auto",
					"message": "Set <kbd>margin: 0 auto</kbd>",
					"options": { "caseSensitive": false }
				}
			]
		},
		{
			"id": "box-model-7",
			"title": "Border Radius",
			"description": "While not part of the classic box model, <kbd>border-radius</kbd> rounds the corners of an element's border box. Use <kbd>50%</kbd> on a square element to create a circle.",
			"task": "Make the avatar image circular with <kbd>border-radius: 50%</kbd>.",
			"previewHTML": "<article class=\"card\"><img class=\"avatar\" src=\"data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'%3E%3Ccircle cx='50' cy='35' r='25' fill='%23666'/%3E%3Ccircle cx='50' cy='90' r='40' fill='%23666'/%3E%3C/svg%3E\" alt=\"Avatar\"><h3>Sarah Chen</h3><p>Frontend Developer</p></article>",
			"previewBaseCSS": "body { font-family: system-ui, sans-serif; padding: 1rem; background: #f5f5f5; } .card { background: white; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); padding: 1rem; text-align: center; } .avatar { width: 80px; height: 80px; background: #ddd; margin-bottom: 8px; } .card h3 { margin: 0 0 4px; } .card p { margin: 0; color: #666; }",
			"sandboxCSS": "",
			"codePrefix": ".avatar {\n  ",
			"initialCode": "",
			"codeSuffix": "\n}",
			"solution": "border-radius: 50%;",
			"previewContainer": "preview-area",
			"validations": [
				{
					"type": "property_value",
					"value": { "property": "border-radius", "expected": "50%" },
					"message": "Set <kbd>border-radius: 50%</kbd>"
				}
			]
		},
		{
			"id": "box-model-8",
			"title": "Complete Card",
			"description": "Let's combine everything. This notification card needs styling to look polished.",
			"task": "Style the notification: add <kbd>padding: 1rem</kbd>, <kbd>border-left: 4px solid coral</kbd>, and <kbd>border-radius: 4px</kbd>.",
			"previewHTML": "<div class=\"alert\"><strong>New message</strong><p>You have 3 unread notifications</p></div>",
			"previewBaseCSS": "body { font-family: system-ui, sans-serif; padding: 1rem; } .alert { background: seashell; } .alert strong { color: coral; } .alert p { margin: 4px 0 0; color: #666; }",
			"sandboxCSS": "",
			"codePrefix": ".alert {\n  ",
			"initialCode": "",
			"codeSuffix": "\n}",
			"solution": "padding: 1rem;\n  border-left: 4px solid coral;\n  border-radius: 4px;",
			"previewContainer": "preview-area",
			"validations": [
				{
					"type": "property_value",
					"value": { "property": "padding", "expected": "1rem" },
					"message": "Set <kbd>padding: 1rem</kbd>"
				},
				{
					"type": "regex",
					"value": "border-left:\\s*4px\\s+solid\\s+coral",
					"message": "Set <kbd>border-left: 4px solid coral</kbd>",
					"options": { "caseSensitive": false }
				},
				{
					"type": "property_value",
					"value": { "property": "border-radius", "expected": "4px" },
					"message": "Set <kbd>border-radius: 4px</kbd>"
				}
			]
		}
	]
}