Book HomeCascading Style Sheets: The Definitive GuideSearch this book Friday 25th of April 2014 11:05:22 AM

10.5. Adapting to the Environment

CSS2 offers the ability to both alter the background does not extend into the margins, and the border is justinside the margin. The CSS specification strongly implies that thebackground extends to the outside edge of the border, since it talksabout the borders being drawn "on top of the background of theelement," but not all browsers seem to agree. This is importantbecause some borders are "intermittent" -- forexample, dotted and dashed styles -- and the element'sbackground should appear in the spaces between the visible portionsof the border.

browser's environment and integrate its look more closely to that of the user's operating system.

10.5.1. Cursors

To achieve the former, we have the cursor property, which lets you declare what shape the browser's cursor will take as it passes over a given element. Want to make a humorous point about download times? Change the cursor to the wait cursor (an hourglass or watch) when the cursor passes over hyperlinks. You can even hook this property up to "cursor files" (which are not defined by the specification), so you could theoretically class your anchors based on where they go and load different icons for each type of link. For example, off-site links could cause the cursor to change into a globe, while links intended to provide help could trigger a question-mark cursor.

10.5.2. Colors

In order to let web pages more closely match the user's desktop environment, there are a whole list of new color keywords like button-highlight, three-d-shadow, and gray-text. These are all intended to use the colors of the user's operating system. In all, there are 27 of these new color keywords. I won't list them all out here, but they're listed in Table 10-1, found at the end of this chapter.

10.5.3. Outlines

While you're moving your cursor around, you might want to show where the focus is set. For example, it might be nice to define a button so that it gets a red box around it when the cursor moves over it. Well, there a number of outline properties, including outline, outline-color, outline-style, and outline-width. To use the example of a red box, you might declare:

IMG.button:hover {outline: solid red 1px;}

This should have the effect described. The outline styles could also be used to set a visible outline for regions in a client-side image map.



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margin + 0 padding = 85px . Thus the top inner edge of the floated element should be at pixel position 85; even though this is higher than the top inner edge of the float's parent element, the math works out such that the specification isn't violated. A similar line of reasoning explains how the left inner edge of the floated element can be placed to the left of the left inner edge of its parent.