How to insert CSS in webpages
The 3 ways to insert CSS into your web pages
There are three ways of inserting a style sheet:
- External style sheet
- Internal style sheet
- Inline style
External style sheet
With an external style sheet, you can change the look of an entire website by changing just one file!
Each page must include a reference to the external style sheet file inside the <link> element. The <link> element goes inside the head section:
<link rel=”stylesheet” type=”text/css” href=”mystyle.css”>
</head>
<link href="myCSSfile.css" rel="stylesheet" type="text/css"> |
or
<style type=”text/css” media=”all”> @import “myCSSfile.css”; </style>
An external style sheet can be written in any text editor. The file should not contain any html tags. The style sheet file must be saved with a .css extension. An example of a style sheet file called “myStyle.css”, is shown below:
background-color: lightblue;
}h1 {
color: navy;
margin-left: 20px;
}
Internal Style Sheet
By creating a CSS block in the web page itself; typically inserted at the top of the web page in between the <head> and </head> tags:
An internal style sheet may be used if one single page has a unique style.
Internal styles are defined within the <style> element, inside the head section of an HTML page:
Example
<style>
body {
background-color: linen;
}h1 {
color: maroon;
margin-left: 40px;
}
</style>
</head>
Inline Styles
By inserting the CSS code right on the tag itself:
An inline style may be used to apply a unique style for a single element.
An inline style loses many of the advantages of a style sheet (by mixing content with presentation). Use this method sparingly!
To use inline styles, add the style attribute to the relevant tag. The style attribute can contain any CSS property. The example shows how to change the color and the left margin of a <h1> element:
Example
Multiple Style Sheets
If some properties have been defined for the same selector in different style sheets, the value will be inherited from the more specific style sheet.
For example, assume that an external style sheet has the following properties for the <h1> element:
color: navy;
margin-left: 20px;
}
then, assume that an internal style sheet also has the following property for the <h1> element:
color: orange;
}
If the page with the internal style sheet also links to the external style sheet the properties for the <h1> element will be:
margin-left: 20px;
Multiple Styles Will Cascade into One
Styles can be specified:
- in an external CSS file
- inside the <head> section of an HTML page
- inside an HTML element
Cascading order
What style will be used when there is more than one style specified for an HTML element?
Generally speaking we can say that all the styles will “cascade” into a new “virtual” style sheet by the following rules, where number three has the highest priority:
- Browser default
- External and internal style sheets (in the head section)
- Inline style (inside an HTML element)
<style type=”text/css” media=”all”> @import “myCSSfile.css”; </style>
