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Basic CSS

CSS(Cascading Style Sheets):-

 

CSS Introduction:-

  • CSS stands for Cascading Style Sheets
  • CSS describes how HTML elements are to be displayed on screen, paper, or in other media
  • CSS saves a lot of work. It can control the layout of multiple web pages all at once
  • External stylesheets are stored in CSS files
CSS Syntax

CSS selector

The selector points to the HTML element you want to style.

The declaration block contains one or more declarations separated by semicolons.

Each declaration includes a CSS property name and a value, separated by a colon.

Multiple CSS declarations are separated with semicolons, and declaration blocks are surrounded by curly braces.

Example

In this example all <p> elements will be center-aligned, with a red text color:

{
  color: red;
  text-align: center;
}
Try it Yourself »

CSS Selectors:-

CSS selectors are used to "find" (or select) the HTML elements you want to style.

We can divide CSS selectors into five categories:

This page will explain the most basic CSS selectors.

The CSS element Selector

The element selector selects HTML elements based on the element name.

Example

Here, all <p> elements on the page will be center-aligned, with a red text color: 

{
  text-align: center;
  color: red;
}
Try it Yourself »

The CSS id Selector

The id selector uses the id attribute of an HTML element to select a specific element.

The id of an element is unique within a page, so the id selector is used to select one unique element!

To select an element with a specific id, write a hash (#) character, followed by the id of the element.

Example

The CSS rule below will be applied to the HTML element with id="para1": 

#para1 {
  text-align: center;
  color: red;
}
Try it Yourself »

Note: An id name cannot start with a number!



The CSS class Selector

The class selector selects HTML elements with a specific class attribute.

To select elements with a specific class, write a period (.) character, followed by the class name.

Example

In this example all HTML elements with class="center" will be red and center-aligned: 

.center {
  text-align: center;
  color: red;
}
Try it Yourself »

You can also specify that only specific HTML elements should be affected by a class.

Example

In this example only <p> elements with class="center" will be red and center-aligned: 

p.center {
  text-align: center;
  color: red;
}
Try it Yourself »

HTML elements can also refer to more than one class.

Example

In this example the <p> element will be styled according to class="center" and to class="large": 

<p class="center large">This paragraph refers to two classes.</p>
Try it Yourself »

Note: A class name cannot start with a number!

The CSS Universal Selector

The universal selector (*) selects all HTML elements on the page.

Example

The CSS rule below will affect every HTML element on the page: 

{
  text-align: center;
  color: blue;
}
Try it Yourself »

The CSS Grouping Selector

The grouping selector selects all the HTML elements with the same style definitions.

Look at the following CSS code (the h1, h2, and p elements have the same style definitions):

h1 {
  text-align: center;
  color: red;
}

h2 {
  text-align: center;
  color: red;
}

{
  text-align: center;
  color: red;
}

It will be better to group the selectors, to minimize the code.

To group selectors, separate each selector with a comma.

Example

In this example we have grouped the selectors from the code above: 

h1, h2, p {
  text-align: center;
  color: red;
}
Try it Yourself »

All CSS Simple Selectors

SelectorExampleExample description
#id#firstnameSelects the element with id="firstname"
.class.introSelects all elements with class="intro"
element.classp.introSelects only <p> elements with class="intro"
**Selects all elements
elementpSelects all <p> elements
element,element,..div, pSelects all <div> elements and all <p> elements
Three Ways to Insert CSS:-

There are three ways of inserting a style sheet:

  • External CSS
  • Internal CSS
  • Inline CSS

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 <link> element, inside the head section.

Example

External styles are defined within the <link> element, inside the <head> section of an HTML page:

<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="mystyle.css">
</head>
<body>

<h1>This is a heading</h1>
<p>This is a paragraph.</p>

</body>
</html>
Try it Yourself »

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 and the unit (such as margin-left: 20 px;). The correct way is: 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 <style> element, inside the head section.

Example

Internal styles are defined within the <style> element, inside the <head> section of an HTML page:

<!DOCTYPE html>
<html>
<head>
<style>
body {
  background-color: linen;
}

h1 {
  color: maroon;
  margin-left: 40px;
}
</style>
</head>
<body>

<h1>This is a heading</h1>
<p>This is a paragraph.</p>

</body>
</html>
Try it Yourself »

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:

<!DOCTYPE html>
<html>
<body>

<h1 style="color:blue;text-align:center;">This is a heading</h1>
<p style="color:red;">This is a paragraph.</p>

</body>
</html>
Try it Yourself »

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 <h1> element:

h1 {
  color: navy;
}

Then, assume that an internal style sheet also has the following style for the <h1> element:

h1 {
  color: orange;   
}

Example

If the internal style is defined after the link to the external style sheet, the <h1> elements will be "orange":

<head>
<link rel="stylesheet" type="text/css" href="mystyle.css">
<style>
h1 {
  color: orange;
}
</style>
</head>
Try it Yourself »

Example

However, if the internal style is defined before the link to the external style sheet, the <h1> elements will be "navy": 

<head>
<style>
h1 {
  color: orange;
}
</style>
<link rel="stylesheet" type="text/css" href="mystyle.css">
</head>
Try it Yourself »

HTML and CSS Comments 

Comments are used to explain the code, and may help when you edit the source code at a later date.

Comments are ignored by browsers.

A CSS comment is placed inside the <style> element, and starts with /* and ends with */:

Example

/* This is a single-line comment */
{
  color: red;
}
Try it Yourself »

You can add comments wherever you want in the code:

Example

{
  color: red;  /* Set text color to red */
}
Try it Yourself »

Comments can also span multiple lines: 

Example

/* This is
a multi-line
comment */


{
  color: red;
}
Try it Yourself »

CSS Comments:-

Comments are used to explain the code, and may help when you edit the source code at a later date.

Comments are ignored by browsers.

A CSS comment is placed inside the <style> element, and starts with /* and ends with */:

Example

/* This is a single-line comment */
{
  color: red;
}
Try it Yourself »

You can add comments wherever you want in the code:

Example

{
  color: red;  /* Set text color to red */
}
Try it Yourself »

Comments can also span multiple lines: 

Example

/* This is
a multi-line
comment */


{
  color: red;
}
Try it Yourself »
CSS Color Names:-


In CSS, a color can be specified by using a predefined color name:

Tomato
Orange
DodgerBlue
MediumSeaGreen
Gray
SlateBlue
Violet
LightGray























CSS Background Color

You can set the background color for HTML elements:

Hello World



Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat.

Example

<h1 style="background-color:DodgerBlue;">Hello World</h1>
<p style="background-color:Tomato;">Lorem ipsum...</p>

Try it Yourself »
CSS Text Color

You can set the color of text:

Hello World

Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat.

Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex ea commodo consequat.

Example

<h1 style="color:Tomato;">Hello World</h1>
<p style="color:DodgerBlue;">Lorem ipsum...</p>
<p style="color:MediumSeaGreen;">Ut wisi enim...</p>
Try it Yourself »

CSS Border Color


Hello World

Hello World

Hello World

Example

<h1 style="border:2px solid Tomato;">Hello World</h1>
<h1 style="border:2px solid DodgerBlue;">Hello World</h1>
<h1 style="border:2px solid Violet;">Hello World</h1>
Try it Yourself »

CSS Color Values

In CSS, colors can also be specified using RGB values, HEX values, HSL values, RGBA values, and HSLA values:

Same as color name "Tomato":

rgb(255, 99, 71)
#ff6347
hsl(9, 100%, 64%)

Same as color name "Tomato", but 50% transparent:

rgba(255, 99, 71, 0.5)
hsla(9, 100%, 64%, 0.5)

<h1 style="background-color:rgb(255, 99, 71);">...</h1>
<h1 style="background-color:#ff6347;">...</h1>
<h1 style="background-color:hsl(9, 100%, 64%);">...</h1>

<h1 style="background-color:rgba(255, 99, 71, 0.5);">...</h1>
<h1 style="background-color:hsla(9, 100%, 64%, 0.5);">...</h1>
Try it Yourself »

Learn more about Color Values

You will learn more about RGB, HEX and HSL in the next chapters.


An RGB color value represents RED, GREEN, and BLUE light sources.










Example

Example

RGBA Value












Example




HEX Value




















Example



















Example















3 Digit HEX Value










Example













HSL Value



















Example



















Saturation:-






Example



















Lightness




Example


















Shades of Gray




Example















HSLA Value



















Example















CSS background:-









CSS background-color



Example












Other Elements



Example










Opacity / Transparency


















Example









Transparency using RGBA
























Example






CSS background-image:-





Example








Example













Example






CSS background-repeat:-





Example








Example








CSS background-repeat: no-repeat



Example








CSS background-position



Example






CSS background-attachment:-




Example









Example
















CSS Border Style













Example



















CSS Border Width:-





Example

















CSS Border Color:-








Example














Specific Side Colors




Example






HEX Values



Example





RGB Values



Example





HSL Values



Example

















The CSS margin properties are used to create space around elements, outside of any defined borders.






Margin - Individual Sides










Example







Margin - Shorthand Property











Example










Example









Example









Example






The auto Value





Example






The inherit Value



Example







CSS Padding:-





Padding - Individual Sides










Example













CSS Setting height and width




CSS height and width Values






CSS height and width Examples







Example
















The CSS Box Model

In CSS, the term "box model" is used when talking about design and layout.

The CSS box model is essentially a box that wraps around every HTML element. It consists of: margins, borders, padding, and the actual content. The image below illustrates the box model:

Explanation of the different parts:

  • Content - The content of the box, where text and images appear
  • Padding - Clears an area around the content. The padding is transparent
  • Border - A border that goes around the padding and content
  • Margin - Clears an area outside the border. The margin is transparent

The box model allows us to add a border around elements, and to define space between elements. 

   Example

    Demonstration of the box model:

div {
  width: 300px;
  border: 15px solid green;
  padding: 50px;
  margin: 20px;
}
   Try it Yourself »



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