The CSS Box Model is a fundamental concept that defines how elements are structured and rendered on a webpage. It describes the space that each HTML element occupies, consisting of four layers. Here’s a breakdown:
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Content: This is the actual content inside the element, such as text, images, or other media.
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Padding: Padding is the space between the content and the element’s border. It creates an area inside the element around the content, but it does not have a background (unless specified).
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Border: This is a line that surrounds the padding and the content. It can be styled (e.g., thickness, color, solid or dashed lines). Borders can be removed entirely, or customized as needed.
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Margin: Margin is the space outside the border, creating a gap between this element and others around it. Margins are transparent and can collapse (e.g., if two elements have margins next to each other).
.box {
width: 200px;
height: 100px;
padding: 10px;
border: 5px solid black;
margin: 20px;
}In this case, the content has a width of 200px and a height of 100px. There’s padding of 10px around the content, a border that is 5px thick, and a margin of 20px outside the border.
The overall width and height of the element include not just the content, but also the padding, border, and margin. The total size would be calculated as:
- Total Width:
width + padding-left + padding-right + border-left + border-right + margin-left + margin-right - Total Height:
height + padding-top + padding-bottom + border-top + border-bottom + margin-top + margin-bottom
Understanding the box model is essential when working on layouts and positioning elements on a webpage.