CSS Rules
A CSS rule is a statement or series of
statements that tells the web browser how to render a certain element or
elements on the page. Each statement in a CSS rule starts with a
selector, which is the element to which the rule will
be applied. For example, in the following assignment, h1
is the selector that is being given a font
size 240 percent larger than the default:
h1 { font-size:240%; }
All properties to be changed in rules must appear within the
{
and }
symbols that follow the selector. The part
before the colon (font-size
, in this
example) is the property to be changed, while the part after the colon is
the value applied to it (240%
, in this
case). Providing a value of 240%
to the
font-size
property of the h1
selector ensures that the contents of all
<h1>...</h1>
tags will be
displayed at a font size that is 240 percent larger than the default
size.
Lastly comes a ;
(semicolon) to
end the statement. In this instance, because font-size
is the last property in the rule, the
semicolon is not required (but it would be if another assignment were to
follow).
Using Semicolons
In CSS, semicolons are used to separate multiple CSS statements on the same line. But if there is only one statement in a rule (or in an inline style setting within an HTML tag), you can omit the semicolon, as you can for the final statement in a group.
However, to avoid hard-to-find CSS errors, you may prefer to always use a semicolon after every CSS setting. You can then copy and paste them, and otherwise ...
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