A CSS (cascading style sheet) file allows you to separate your web
sites (X)HTML content from it’s style. As always you use your (X)HTML
file to arrange the content, but all of the presentation (fonts, colors,
background, borders, text formatting, link effects & so on…) are
accomplished within a CSS.
At this point you have some choices of how to use the CSS, either internally or externally.
Internal Stylesheet
First we will explore the internal method. This way you are simply
placing the CSS code within the <head></head> tags of each
(X)HTML file you want to style with the CSS. The format for this is
shown in the example below.
<head>
<title><title>
<style type=”text/css”>
CSS Content Goes Here
</style>
</head>
<body>
With this method each (X)HTML file contains the CSS code needed to
style the page. Meaning that any changes you want to make to one page,
will have to be made to all. This method can be good if you need to
style only one page, or if you want different pages to have varying
styles.
External Stylesheet
Next we will explore the external method. An external CSS file can be
created with any text or HTML editor such as “Notepad” or
“Dreamweaver”. A CSS file contains no (X)HTML, only CSS. You simply save
it with the .css file extension. You can link to the file externally by
placing one of the following links in the head section of every (X)HTML
file you want to style with the CSS file.
<link rel=”stylesheet” type=”text/css” href=“Path To stylesheet.css” />
Or you can also use the @import method as shown below
<style type=”text/css”>@import url(Path To stylesheet.css)</style>
Either of these methods are achieved by placing one or the other in the head section as shown in example below.
<head>
<title><title>
<link rel=”stylesheet” type=”text/css”href=”style.css” />
</head>
<body>
or
<head>
<title><title>
<style type=”text/css”>
@import url(Path To stylesheet.css) </style>
</head>
<body>
By using an external style sheet, all of your (X)HTML files link to
one CSS file in order to style the pages. This means, that if you need
to alter the design of all your pages, you only need to edit one .css
file to make global changes to your entire website.
Here are a few reasons this is better.
- Easier Maintenance
- Reduced File Size
- Reduced Bandwidth
- Improved Flexibility
Are you getting the idea? It’s really cool.
Cascading Order
In the previous paragraphs, I have explained how to link to a css
file either internally or externally. If you understood, than I am doing
a good job. If not don’t fret, there is a long way to go before we are
finished. Assuming you have caught on already, you are probably asking,
well can I do both? The answer is yes. You can have both internal,
external, and now wait a minute a third way? Yes inline styles also.
Inline Styles
I have not mentioned them until now because in a way they defeat the
purpose of using CSS in the first place. Inline styles are defined right
in the (X)HTML file along side the element you want to style. See
example below.
<p style=”color: #ff0000;”>Some red text</p>
Some red text
Inline styles will NOT allow the user to change styles of elements or text formatted this way
So, which is better?
So with all these various ways of inserting CSS into your (X)HTML
files, you may now be asking well which is better, and if I use more
than one method, in what order do these different ways load into my
browser?
All the various methods will cascade into a new “pseudo” stylesheet in the following order:
- Inline Style (inside (X)HTML element)
- Internal Style Sheet (inside the <head> tag)
- External Style Sheet
As far as which way is better, it depends on what you want to do. If
you have only one file to style then placing it within the
<head></head> tags (internal) will work fine. Though if you
are planning on styling multiple files then the external file method is
the way to go.
Choosing between the <link related=> & the @import methods
are completely up to you. I will mention that the @import method may
take a second longer to read the CSS file in Internet Explorer than the
<link related=> option. To combat this see
Flash of unstyled content
Users with Disabilities
The use of external style sheets also can benefit users that suffer
from disabilities. For instance, a user can turn off your stylesheet or
substitute one of there own to increase text size, change colors and so
on. For more information on making your website accessible to all users
please read
Dive into accessibility
Power Users
Swapping stylesheets is beneficial not only for users with
disabilities, but also power users who are particular about how they
read Web documents.
Browser Issues
You will discover as you delve farther into the world of CSS that all
browsers are not created equally, to say the least. CSS can and will
render differently in various browsers causing numerous headaches.
is one of the most popular HTML editors on the web.