University:
Boston University
Course:
MET CS 201 | Introduction to Programming
Academic year:

2024
Views:

447

Pages:

2
Author:

Deja Hood

CSS Box Models All HTML elements can be considered as boxes. The term "box model" is used when talking about design and layout. The box model is essentially a box that wraps around HTML elements, and it consists of: margins, borders, padding, and the actual content. The box model allows us to place a border around elements and space elements in relation to other elements. The image below illustrates the box model: • Margin - Clears an area around the border. The margin does not have a background color, it is completely transparent • Border - A border that goes around the padding and content. The border is affected by the background color of the box • Padding - Clears an area around the content. The padding is affected by the background color of the box • Content - The content of the box, where text and images appear. Width and Height of an Element NOTE: When you specify the width and height properties of an element, you are just setting the width and height of the content area. To know the full size of the element, you must also add its surrounding padding, border and margin. The total width of the element in the example below is 300px: width:250px; padding:10px; border:5px solid gray; margin:10px; Because: 250px (width) + 20px (left and right padding) + 10px (left and right border) + 20px (left and right margin) = 300px TOTAL ELEMENT WIDTH = width + left padding + right padding + left border + right border + left margin + right margin TOTAL ELEMENT HEIGHT = height + top padding + bottom padding + top border + bottom border + top margin + bottom margin EXAMPLE: < html > < head > < style type="text/css" > div.ex{ width:220px; padding:10px; border:5px solid gray; margin:0px; } < / style > < / head > < / html > NOTE: This may look different in different browsers. Most versions of Internet Explorer, for example, include padding and border in the width. This can be fixed with a DOCTYPE declaration, but this is trivial. The point is that your website will not look identical in all browsers.