Why Does Body Element Background Styling Affect the Entire Viewport?

How Background Styling of the Body Element Influences the Entire Viewport

When styling the background of the body element, developers may encounter an unexpected effect where the styling extends beyond the body element and covers the entire viewport. This behavior stems from the role of the body element as the root element in CSS.

According to the specifications outlined in W3C's CSS Standard, the background styling applied to the root element (in this case, the body element) affects the entire canvas of the webpage. This canvas encompasses the available display area in the browser's viewport, extending beyond the boundaries of the body element.

In the example provided:

body {
  width: 700px;
  height:200px;
  border: 5px dotted red;
  background-color: blue;
}

The width and height properties are applied specifically to the body element, as expected. However, the background color spans the entire screen because the body element is the root element, and its background styling influences the entire canvas, as dictated by the CSS specifications.

Essentially, the background of the body element becomes the background of the entire webpage area in the browser, rather than only styling the body element itself. This illustrates the unique behavior associated with styling the background of the root element in CSS.

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