CODEWITHSUNDEEP
htmlcss
Alexandre Khoury
Alexandre Khoury

Reputation: 4022

Not centered horizontally because of position absolute

I made this:

HTML:

<body>
<div id="header" >
</div>
<div id="main" >
</div>
<div id="footer" >
</div>
</body>

CSS:

body
{
    margin:0px;
}
#header
{
    width:100%;
    background-color:black;
    height:60px;
}
#main
{
    width:300px;
    border:1px dotted black;
    margin:0 auto;
}
#footer
{
    width:100%;
    background-color:black;
    height:40px;
    position:absolute;
    bottom:0px;
}

http://jsfiddle.net/VpwQQ/2/

But as you can see, the main div doesn't have a height.

Then I replaced my css by that:

body
{
    margin:0px;
}
#header
{
    width:100%;
    background-color:black;
    height:60px;
}
#main
{
    width:300px;
    border:1px dotted black;
    position:absolute;
    margin:0 auto;
    bottom:60px;
    top:80px;
}
#footer
{
    width:100%;
    background-color:black;
    height:40px;
    position:absolute;
    bottom:0px;
}

http://jsfiddle.net/VpwQQ/1/

But then, the horizontal center doesn't work.

How can I do this design (div centered and that takes all the page in height between the header and footer with a 20 px magin) ?

Upvotes: 0

Views: 145

Answers (4)

Guffa
Guffa

Reputation: 700252

You can't use automatic margins on an absolutely positioned element, as it's not in the document flow any more.

Use width: 100% on the #main div, then put another element inside it that you center using automatic margins.

Demo: http://jsfiddle.net/Guffa/VpwQQ/9/

Note: You may need to use height: 100% on the body and html elements for the bottom sizing to work on the #main element.

Upvotes: 1

unludo
unludo

Reputation: 5010

I added a div inside #main.

Main now has a 100% width.

Inside, put a div of 300px, with no absolute position.

I forked your fiddle: http://jsfiddle.net/8U9P6/

Personnally I prefer the javascript solution and not using the absolute position. But this solution seems to work.

Add and overflow to contain the content in the inside div: http://jsfiddle.net/M2nZc/

Note that the page will not grow as it is absolute position.

Upvotes: 1

bakkerjoeri
bakkerjoeri

Reputation: 223

Once you fill your #main div with content, it will automatically gain height according to the content. You can simply fill it with a few paragraphs of lorem ispum to simulate content. You can now remove the absolute position and positioning CSS.

Centering a div using the "0 auto" shorthand only works when the parent element (which, for the #main div, is the body element) has a defined width. To do this, try giving your body element a width of 100%. Doing this is something that you might want to make a habit of in you CSS.

To have your #main div always be 20px below the #header div, simply add 20px of margin-bottom to your #header div. Do the same below the #main div to space the footer.

Summed up (without the footer at the bottom, for now) your CSS might read something like this:

body {
  width: 100%
  margin: 0px;
}

#header {
  width: 100%;
  height: 60px;
  margin-bottom: 20px; /*here we space the header 20px from the next element*/
  background-color: black;

}

#main {
  width: 300px;
  margin: 0 auto 20px auto; /*we append the margin to include 20px of spacing at the bottom*/
  border:1px dotted black;
}

#footer {
  width:100%;
  height:40px;
  background-color:black;
}

Example: http://jsfiddle.net/WEx3j/

If you want the footer to be 'sticky' (always be at the very bottom of your website), I advise you to employ this method.

I hope this clarified a few things.

Upvotes: 0

Thomas Clayson
Thomas Clayson

Reputation: 29925

I'm not sure what you're trying to do, but I'll give my explaination of what's going to happen with your code:

Your #main div doesn't have a height because it doesn't have a height CSS property, nor does it have any content.

You should add either a height: 100px or just add some content and you will see it gets a height.

The reason why I ask what you want to do is because you're not very clear as to what you want your final product to look like.

You're going to have another problem with the footer. If you use position absolute it sticks to the bottom at the moment. Set the height of the #main div to something ridiculously high and you'll see that when you have to scroll down the page the footer stays where it is. See http://jsfiddle.net/VpwQQ/3/

You should use position: fixed but this will keep it on the bottom of the WINDOW and not the DOCUMENT. So then you get into the problem of having to use Javascript in order to measure the document height and setting positions appropriately. Not sure what you're trying to do, but if you're just trying to lay out a website then use standard relative positioning to push the footer down naturally below the #main div.

Edit:

See http://jsfiddle.net/VpwQQ/4/ if you're just trying to set up a normal website layout.

If you want the footer to "stick" to the bottom of the page all the time then you will need to use position: fixed but I don't think this works across all browsers. See http://jsfiddle.net/VpwQQ/6/

Lastly, to get both footer and header to "stick" see http://jsfiddle.net/VpwQQ/8/

Upvotes: 1

Related Questions