Chapter
2 - CSS Syntax
The
syntax for CSS is different than that of (X)HTML markup. Though it is not too
confusing, once you take a look at it. It consists of only 3 parts.
selector {
property: value }
The
selector is the (X)HTML element that you want to style. The property is the
actual property title, and the value is the style you apply to that property.
Each
selector can have multiple properties, and each property within that selector
can have independent values. The property and value are seperated with a colon
and contained within curly brackets. Multiple properties are seperated by a
semi colon. Multiple values within a
property
are sperated by commas, and if an individual value contains more than one word
you surround it with quotation marks. As shown below.
body {
background: #eeeeee;
font-family: "Trebuchet
MS", Verdana, Arial, serif;
}
As
you can see in the above code I have seperated the color from the font-family
with a semi-colon, seperated the various fonts with commas and contained the
"Trebuchet MS" within quotations marks. The final result sets the
body color to light grey, and sets the font to ones that
most
users will have installed on there computer.
I
have changed the way I layout my code, but you can arrange it in one line if
you choose. I find that it is more readable if I spread each property to a
seperate line, with a 2 space indention.
Inheritance
When
you nest one element inside another, the nested element will inherit the
properties assigned to the containing element. Unless you modify the inner
elements values independently.
For
example, a font declared in the body will be inherited by all text in the file
no matter the containing element, unless you declare another font for a
specific nested element.
body
{font-family: Verdana, serif;}
Now
all text within the (X)HTML file will be set to Verdana.
If
you wanted to style certain text with another font, like an h1 or a paragraph
then you could do the following.
h1 {font-family: Georgia,
sans-serif;}
p {font-family:
Tahoma, serif;}
Now
all <h1> tags within the file will be set to Georgia and all <p>
tags are set to Tahoma, leaving text within other elements unchanged from the
body declaration of Verdana.
There
are instances where nested elements do not inherit the containing elements
properties.
For
example, if the body margin is set to 20 pixels, the other elements within the
file will not inherit the body margin by default.
body {margin:
20px;}
Combining
Selectors
You
can combine elements within one selector in the following fashion.
h1, h2, h3, h4, h5, h6 {
color: #009900;
font-family: Georgia, sans-serif;
}
As
you can see in the above code, I have grouped all the header elements into one
selector. Each one is seperated by a comma. The final result of the above code
sets all headers to green and to the specified font. If the user does not have
the first font I declared it will go to another sans-serif font the user has
installed on there computer.
Comment
tags
Comments
can be used to explain why you added certain selectors within your css file. So
as to help others who may see your file, or to help you remember what you we're
thinking at a later date. You can add comments that will be ignored by browsers
in the following manner.
/* This is a
comment */
You
will note that it begins with a / (forward slash) and than an * (asterisks)
then the comment, then the closing tag which is just backward from the opening
tag * (asterisks) then the / (forward slash).
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