HTML STYLE SHEETS AND CSS by acslater

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									                                          LAYERS
Layer – a container with content, whether text, graphic, or both. Layers can be stacked on top of
each other or over parts of each other to create some interesting effects.

** Layers offer a great advantage for laying out a Web site but are only supported by the most
current browsers. Using layers will cause files to download more rapidly. But for browsers that
do no support layers, you can still use layers as a design tool and then Dreamweaver can convert
them into more commonly compliant tables.

Nested Layers – layers that are inside of, or children to, other layers. When you create a nested
layer, the parent layer can pass its attributes down to the child layers. This will be important
when you learn about animations and behaviors.

Z-Index (Stacking Order)
Z-axis is the third dimension that runs from the surface of the monitor out to you (stacking
order). The normal Web-page layer has a z-index of zero and any layers added to the page
increase in increments of 1.

3 Functions Used to Create and Edit Layers
1. Draw Layer Button – Found on the Common Palette. You click the button and draw a
   rectangular layer in the Document Window.
2. Property Inspector – When a layer is selected, the Property inspector shows the properties of
   the layer that may be modified by typing something different.
3. Layers Panel – Can select a layer by clicking its name, can change its ID, can change the z-
   index by dragging a layer up or down in the order.

Using CSS Selector
Layers names are IDs because when a name is applied to a layer, the name is stored in the <div>
tag. The # (pound symbol) is used when selecting an ID. Ex. div#background

Tracing Images
 Beneficial to the design of graphically oriented pages
 Useful in a collaborative environment where a graphic designer builds the look but doesn’t
   create the code
 Allows you to place a background graphic on a page and use this background graphic as a
   guide for placement of elements.
 You would want to add layers so text can become live text instead of graphic text and to have
   links to the page.

Converting Layers to Tables
 Layers may not overlap or the conversion will not work
 Cells in tables cannot be animated or moved
 File size will always be larger with the table format than if using the layers format.

								
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