Positioning can be tricky sometimes!
Decide which element to display in front!
Elements can overlap!
Positioning
The CSS positioning properties allow you to position an element. It can also place an element behind another, and specify what should happen when an element's content is too big.
Elements can be positioned using the top, bottom, left, and right properties. However, these properties will not work unless the position property is set first. They also work differently depending on the positioning method.
There are four different positioning methods.
Static Positioning
HTML elements are positioned static by default. A static positioned element is always positioned according to the normal flow of the page.
Static positioned elements are not affected by the top, bottom, left, and right properties.
Fixed Positioning
An element with fixed position is positioned relative to the browser window.
It will not move even if the window is scrolled:
Example
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<style type="text/css">
p.pos_fixed
{
position:fixed;
top:30px;
right:5px;
}
</style>
</head>
<body>
<p class="pos_fixed">Some more text</p>
<p><b>Note:</b> IE7 and IE8 supports the fixed value only if a
!DOCTYPE is specified.</p>
<p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p><p>Some text</p>
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
Result:
Note: IE7 and IE8 supports the fixed value only if a !DOCTYPE is specified.
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Some text
Note: IE7 and IE8 support the fixed value only if a !DOCTYPE is specified.
Fixed positioned elements are removed from the normal flow. The document and other elements behave like the fixed positioned element does not exist.
Fixed positioned elements can overlap other elements.
Relative Positioning
A relative positioned element is positioned relative to its normal position.
Example
<html>
<head>
<style type="text/css">
h2.pos_left
{
position:relative;
left:-20px;
}
h2.pos_right
{
position:relative;
left:20px;
}
</style>
</head>
<body>
<h2>This is a heading with no position</h2>
<h2 class="pos_left">This heading is moved left according to its normal position</h2>
<h2 class="pos_right">This heading is moved right according to its normal position</h2>
<p>Relative positioning moves an element RELATIVE to its original position.</p>
<p>The style "left:-20px" subtracts 20 pixels from the element's original left position.</p>
<p>The style "left:20px" adds 20 pixels to the element's original left position.</p>
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
Result:
This is a heading with no position
This heading is moved left according to its normal position
This heading is moved right according to its normal position
Relative positioning moves an element RELATIVE to its original position.
The style "left:-20px" subtracts 20 pixels from the element's original left position.
The style "left:20px" adds 20 pixels to the element's original left position.
The content of relatively positioned elements can be moved and overlap other elements, but the reserved space for the element is still preserved in the normal flow.
Example
<html>
<head>
<style type="text/css">
h2.pos_top
{
position:relative;
top:-50px;
}
</style>
</head>
<body>
<h2>This is a heading with no position</h2>
<h2 class="pos_top">This heading is moved upwards according to its normal position</h2>
<p><b>Note:</b> Even if the content of the relatively positioned element is moved, the reserved space for the element is still preserved in the normal flow.</p>
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
Result:
This is a heading with no position
This heading is moved upwards according to its normal position
Note: Even if the content of the relatively positioned element is moved, the reserved space for the element is still preserved in the normal flow.
Relatively positioned elements are often used as container blocks for absolutely positioned elements.
Absolute Positioning
An absolute position element is positioned relative to the first parent element that has a position other than static. If no such element is found, the containing block is <html>:
Example
<html>
<head>
<style type="text/css">
h2
{
position:absolute;
left:100px;
top:150px;
}
</style>
</head>
<body>
<h2>This is a heading with an absolute position</h2>
<p>With absolute positioning, an element can be placed anywhere on a page. The heading below is placed 100px from the left of the page and 150px from the top of the page.</p>
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
With absolute positioning, an element can be placed anywhere on a page. The heading below is placed 100px from the left of the page and 150px from the top of the page.
This is a heading with an absolute position
Absolutely positioned elements are removed from the normal flow. The document and other elements behave like the absolutely positioned element does not exist.
Absolutely positioned elements can overlap other elements.
Overlapping Elements
When elements are positioned outside the normal flow, they can overlap other elements.
The z-index property specifies the stack order of an element (which element should be placed in front of, or behind, the others).
An element can have a positive or negative stack order:
Example
<html>
<head>
<style type="text/css">
img
{
position:absolute;
left:0px;
top:0px;
z-index:-1;
}
</style>
</head>
<body>
<h1>This is a heading</h1>
<img src="Your_image.gif" width="100" height="140" />
<p>Because the image has a z-index of -1, it will be placed behind the text.</p>
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
An element with greater stack order is always in front of an element with a lower stack order.
Note: If two positioned elements overlap, without a z-index specified, the element positioned last in the HTML code will be shown on top.
More Examples
Set the shape of an element
This example demonstrates how to set the shape of an element. The element is clipped into this shape, and displayed.
Example
<html>
<head>
<style type="text/css">
img
{
position:absolute;
clip:rect(0px,60px,200px,0px);
}
</style>
</head>
<body>
<img src="w3css.gif" width="100" height="140" />
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
How to show overflow in an element using scroll
This example demonstrates how to set the overflow property to create a scroll bar when an element's content is too big to fit in a specified area.
Example
<html>
<head>
<style type="text/css">
div.scroll
{
background-color:#00FFFF;
width:100px;
height:100px;
overflow:scroll;
}
div.hidden
{
background-color:#00FF00;
width:100px;
height:100px;
overflow:hidden;
}
</style>
</head>
<body>
<p>The overflow property specifies what to do if the content of an element exceeds the size of the element's box.</p>
<p>overflow:scroll</p>
<div class="scroll">You can use the overflow property when you want to have better control of the layout. The default value is visible.</div>
<p>overflow:hidden</p>
<div class="hidden">You can use the overflow property when you want to have better control of the layout. The default value is visible.</div>
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
Result:
The overflow property specifies what to do if the content of an element exceeds the size of the element's box.
overflow:scroll
You can use the overflow property when you want to have better control of the layout. The default value is visible.
overflow:hidden
This example demonstrates how to set the browser to automatically handle overflow.
Example
<html>
<head>
<style type="text/css">
div
{
background-color:#00FFFF;
width:150px;
height:150px;
overflow:auto;
}
</style>
</head>
<body>
<p>The overflow property decides what to do if the content inside an element exceeds the given width and height properties.</p>
<div>
You can use the overflow property when you want to have better control of the layout. Try to change the overflow property to: visible, hidden, scroll, or inherit and see what happens. The default value is visible.
</div>
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
Result:
The overflow property decides what to do if the content inside an element exceeds the given width and height properties.
You can use the overflow property when you want to have better control of the layout. Try to change the overflow property to: visible, hidden, scroll, or inherit and see what
This example demonstrates how to change the cursor.
Example
<html>
<body>
<p>Mouse over the words to change the cursor.</p>
<span style="cursor:auto">auto</span><br />
<span style="cursor:crosshair">crosshair</span><br />
<span style="cursor:default">default</span><br />
<span style="cursor:e-resize">e-resize</span><br />
<span style="cursor:help">help</span><br />
<span style="cursor:move">move</span><br />
<span style="cursor:n-resize">n-resize</span><br />
<span style="cursor:ne-resize">ne-resize</span><br />
<span style="cursor:nw-resize">nw-resize</span><br />
<span style="cursor:pointer">pointer</span><br />
<span style="cursor:progress">progress</span><br />
<span style="cursor:s-resize">s-resize</span><br />
<span style="cursor:se-resize">se-resize</span><br />
<span style="cursor:sw-resize">sw-resize</span><br />
<span style="cursor:text">text</span><br />
<span style="cursor:w-resize">w-resize</span><br />
<span style="cursor:wait">wait</span><br />
</body>
</html>
Try it yourself in Notepad or Dreamweaver by coping and pasting the code above.
Result:
Mouse over the words to change the cursor.
autocrosshair
default
e-resize
help
move
n-resize
ne-resize
nw-resize
pointer
progress
s-resize
se-resize
sw-resize
text
w-resize
wait
All CSS Positioning Properties
The number in the "CSS" column indicates in which CSS version the property is defined (CSS1 or CSS2).
| Property | Description | Values | CSS |
|---|---|---|---|
| bottom | Sets the bottom margin edge for a positioned box | auto length %inherit | 2 |
| clip | Clips an absolutely positioned element | shapeauto inherit | 2 |
| cursor | Specifies the type of cursor to be displayed | urlauto crosshair default pointer move e-resize ne-resize nw-resize n-resize se-resize sw-resize s-resize w-resize text wait help | 2 |
| left | Sets the left margin edge for a positioned box | auto length %inherit | 2 |
| overflow | Specifies what happens if content overflows an element's box | auto hidden scroll visible inherit | 2 |
| position | Specifies the type of positioning for an element | absolute fixed relative static inherit | 2 |
| right | Sets the right margin edge for a positioned box | auto length %inherit | 2 |
| top | Sets the top margin edge for a positioned box | auto length %inherit | 2 |
| z-index | Sets the stack order of an element | numberauto inherit | 2 |
