CSS Getting Started

A CSS file is simply a plain text file saved with the .css extension.

Getting Started with CSS

In this tutorial you’ll learn how easy it is to add style and formatting information to the web pages using CSS. But, before we begin, make sure that you have some working knowledge of HTML.

If you’re just starting out in the world of web development, start learning from here »

Without further ado, let’s get started with the Cascading Style Sheets (CSS).

Including CSS in HTML Documents

CSS can either be attached as a separate document or embedded in the HTML document itself. There are three methods of including CSS in an HTML document:

• Inline styles — Using the style attribute in the HTML start tag.
• Embedded styles — Using the element in the head section of a document.
• External style sheets — Using the element, pointing to an external CSS file.

In this tutorial we will cover all these three methods for inserting CSS one by one.

Note: The inline styles have the highest priority, and the external style sheets have the lowest. It means if you specify styles for an element in both embedded and external style sheets, the conflicting style rules in the embedded style sheet would override the external style sheet.

Inline Styles

Inline styles are used to apply the unique style rules to an element by putting the CSS rules directly into the start tag. It can be attached to an element using the style attribute.

The style attribute includes a series of CSS property and value pairs. Each «property: value» pair is separated by a semicolon ( ; ), just as you would write into an embedded or external style sheets. But it needs to be all in one line i.e. no line break after the semicolon, as shown here:

Example

This is a heading
 
This is a paragraph.
 
This is some text content.

Using the inline styles are generally considered as a bad practice. As style rules are embedded directly inside the HTML tag, it causes the presentation to become mixed with the content of the document; which makes the code hard to maintain and negates the purpose of using CSS.

Note: It’s become impossible to style pseudo-elements and pseudo-classes with inline styles. You should, therefore, avoid the use of style attributes in your code. Using external style sheets is the preferred way to add styles to the HTML documents.

Embedded Style Sheets

Embedded or internal style sheets only affect the document they are embedded in.

Embedded style sheets are defined in the section of an HTML document using the element. You can define any number of elements in an HTML document but they must appear between the and tags. Let’s take a look at an example:

Example

    body < background-color: YellowGreen; >p 
This is a heading
 
This is a paragraph of text.
  

Tip: The type attribute of the and tag (i.e. type=»text/css» ) defines the language of the style sheet. This attribute is purely informative. You can omit this since CSS is the standard and default style sheet language in HTML5.

External Style Sheets

An external style sheet is ideal when the style is applied to many pages of the website.

An external style sheet holds all the style rules in a separate document that you can link from any HTML file on your site. External style sheets are the most flexible because with an external style sheet, you can change the look of an entire website by changing just one file.

You can attach external style sheets in two ways — linking and importing.

Linking External Style Sheets

Before linking, we need to create a style sheet first. Let’s open your favorite code editor and create a new file. Now type the following CSS code inside this file and save it as «style.css».

Example

An external style sheet can be linked to an HTML document using the tag. The tag goes inside the section, as you can see in the following example:

Example

     
This is a heading
 
This is a paragraph of text.
  

Tip: Among all the three methods, using external style sheet is the best method for defining and applying styles to the HTML documents. As you can clearly see with external style sheets, the affected HTML file require minimal changes in the markup.

Importing External Style Sheets

The @import rule is another way of loading an external style sheet. The @import statement instructs the browser to load an external style sheet and use its styles.

You can use it in two ways. The simplest is within the header of your document. Note that, other CSS rules may still be included in the element. Here’s an example:

Example

Similarly, you can use the @import rule to import a style sheet within another style sheet.

Example

@import url("css/layout.css"); @import url("css/color.css"); body

Note: All @import rules must occur at the start of the style sheet. Any style rule defined in the style sheet itself override the conflicting rules in the imported style sheets. However, importing a style sheet within another style sheet is not recommended due to performance issue.

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Yu-Chieh’s Blog (Y.C. Chang)

Ruby on Rails / Rubygems / FullStack / Git / Mac notes.

How to Put Css in Html Body?

• There are two ways to set css file into our html documents.
• first way: using pure javascript to append css file into head part of html.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 

 type="text/javascript">  function loadCSS(filename)  var file = document.createElement("link")  file.setAttribute("rel", "stylesheet")  file.setAttribute("type", "text/css")  file.setAttribute("href", filename)  if (typeof file !== "undefined")  document.getElementsByTagName("head")[0].appendChild(file)  >  //just call a function to load a new CSS:  loadCSS("path_to_css/file.css")  

$('head').append(' rel="stylesheet" type="text/css" href="">'); 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 

    id = "scoped-content">   type = "text/css" scoped>  h1  color: red; >    Hello    World   

Posted by Y.C. Chang (Yu-Chieh Chang) Nov 15 th , 2015 11:49 pm css,, html5,, javascript,, jquery, style,

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Как добавить CSS стили в body веб страницы

В одном из проектов понадобилось добавить новые стили к одной определённой странице, но шаблон позволял менять только содержимое после тега . Чтобы не добавлять ненужные стили на весь сайт, а вставить их только для одной страницы, рассмотрим, какие есть варианты добавления CSS внутри .

1.

Правильно загружать внешние CSS файлы на странице следующим образом:

То есть файлы стилей должны быть загружены внутри тега .

Тем не менее с помощью функции JavaScript можно дополнить код из тела страницы:

Либо вы можете добавить динамические определения, такие как:

2.

Ещё один вариант — просто вставить нужные стили после тега :

   * p  * p 
"Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit. "
 "Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit. " 
"Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit. "
  

Не уверен по поводу валидности получаемого кода, но CSS работает!

3.

Этот вариант также работает:

Но только если не содержит /css в rel (то есть следующий вариант НЕ работает):

4.

Вы можете поместить теги внутри .

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How To Add CSS

When a browser reads a style sheet, it will format the HTML document according to the information in the style sheet.

Three Ways to Insert CSS

There are three ways of inserting a style sheet:

External CSS

With an external style sheet, you can change the look of an entire website by changing just one file!

Each HTML page must include a reference to the external style sheet file inside the element, inside the head section.

Example

External styles are defined within the element, inside the section of an HTML page:

This is a heading

This is a paragraph.

An external style sheet can be written in any text editor, and must be saved with a .css extension.

The external .css file should not contain any HTML tags.

Here is how the «mystyle.css» file looks:

«mystyle.css»

body <
background-color: lightblue;
>

h1 color: navy;
margin-left: 20px;
>

Note: Do not add a space between the property value (20) and the unit (px):
Incorrect (space): margin-left: 20 px;
Correct (no space): margin-left: 20px;

Internal CSS

An internal style sheet may be used if one single HTML page has a unique style.

The internal style is defined inside the element, inside the head section.

Example

Internal styles are defined within the element, inside the section of an HTML page:

This is a heading

This is a paragraph.

Inline CSS

An inline style may be used to apply a unique style for a single element.

To use inline styles, add the style attribute to the relevant element. The style attribute can contain any CSS property.

Example

Inline styles are defined within the «style» attribute of the relevant element:

This is a heading

This is a paragraph.

Tip: An inline style loses many of the advantages of a style sheet (by mixing content with presentation). Use this method sparingly.

Multiple Style Sheets

If some properties have been defined for the same selector (element) in different style sheets, the value from the last read style sheet will be used.

Assume that an external style sheet has the following style for the element:

Then, assume that an internal style sheet also has the following style for the element:

Example

If the internal style is defined after the link to the external style sheet, the elements will be «orange»:

Example

However, if the internal style is defined before the link to the external style sheet, the elements will be «navy»:

Cascading Order

What style will be used when there is more than one style specified for an HTML element?

All the styles in a page will «cascade» into a new «virtual» style sheet by the following rules, where number one has the highest priority:

1. Inline style (inside an HTML element)
2. External and internal style sheets (in the head section)
3. Browser default

So, an inline style has the highest priority, and will override external and internal styles and browser defaults.

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