CSS practical tutorial on fixing the footer to the bottom of the page

This article mainly introduces the actual CSS practice of fixing the footer at the bottom of the page. Pay attention to the issue of CSS clearing floats. Friends in need can refer to

Footer position issues

The footer of a web page is where help links and copyright information are usually placed. The footer should naturally be located at the bottom of the page, but according to general practice, if the web page content before the footer is relatively small, or a monitor with a large vertical resolution is used, the footer may not appear to be on the page. The situation at the bottom is as shown below.

Since the footer is basically a common part of all pages of a website, the amount of content on different pages varies, so it is indeed possible that some pages may not have enough content. Such a question. In addition, especially for footers that contain background colors, this problem will seriously affect the appearance.

So, we hope that the footer can be accurately located at the bottom regardless of the content of the web page.
How to fix the footer to the bottom
Is absolute positioning feasible?

Maybe someone has thought of setting the footer to position:fixed and then positioning it at the bottom. Regardless of IE6, which does not support this attribute value, in effect, if the content of the web page itself is sufficient, this way of writing will cause the footer to appear at the bottom of the browser from the beginning, and when scrolling the web page, the footer will appear at the bottom of the browser. will remain in its original position. This effect is obviously not suitable for most websites.

As you can imagine, the effect we need is:

When the web page has a lot of content, you can only see the bottom footer when you scroll to the bottom.
When the content of the web page is small, the footer is still located at the bottom of the entire page, and the rest is left blank.

Conventional, simple implementation method

CSS Sticky Footer provides a reasonable implementation method for fixing the footer at the bottom. However, on the one hand, this is an English site, and on the other hand, the writing method it provides can still be improved, so this article will refer to its content and give a reasonable implementation method.

First you need such an html structure:

p.wrapper is the outer container for all content in the web page except the footer, and the footer p.footer It's on the same level as it. p.footer_placeholder must be placed at the end of all content on the web page, that is, as the last child element of p.wrapper. Its function will be explained later.

Next write the css and explain it in turn.

html, body{height:100%;}

When the content of the web page is insufficient, the actual height of the body and html may be smaller than the visible range of the browser, so write the height of 100% for the body and html. In addition, the following direct child elements will also use the percentage writing method. The percentage writing method must be effective only when the direct parent element has a certain height definition.

.wrapper{   
    min-height:100%;   
    _height:100%;   
    margin-bottom:-120px;   /*假定页脚的高度为120px*/  
}

All web content is in this p.wrapper, and the minimum height is defined (IE6 uses a hack). Since the parent element of this element is the body that defines 100% height, no matter Regardless of the content, the height of the p.wrapper element will occupy the entire visible range of the browser. Then, set equal negative values ​​for the bottom margin according to the height of the footer, so that the footer will appear exactly at the end of the page content.

.footer, .footer_placeholder{height:120px;}    /*假定页脚的高度为120px*/

p.footer_placeholder, as literally, the placeholder element of the footer, it is just an empty p, the definition height is the same as the footer, it exists to give the footer Leave a spot. Without it, something like this might happen ↓

At this point, the footer fixed at the bottom has been implemented. The sum of the css parts is:

html, body{height:100%;}   
.wrapper{   
    min-height:100%;   
    _height:100%;   
    margin-bottom:-120px;   /*假定页脚的高度为120px*/  
}   
.footer, .footer_placeholder{height:120px;}   
  
如果还需要考虑css初始化和清理浮动，可能你还需要添加下面这部分css：   
  
body{margin:0;}   
.footer_placeholder{clear:both;}

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