ASP.NET + CSS - How do I center elements in middle of the web page vertically and horizontally?

My web form is pretty simple. It has to have three lines of text/ASP.NET elements. The Master page has a header and a footer. I need to center th开发者_如何学Goose three lines in the middle of the page vertically and horizontally, especially if the bottom changes. How do I do this with CSS?

---

In your master page you will want a container and center that, then you will want a div for the main content. the raw code would be something like:

<div id="center">
   <div id="main">
      <p>This text is perfectly vertically and horizontally centered.</p>
   </div><!-- end #main -->
</div><!-- end #center -->

<style>
   #center { position: absolute; top: 50%; width: 100%; height: 1px; overflow: visible }
   #main { position: absolute; left: 50%; width: 720px; margin-left: -360px; height: 540px; top: -270px } 
</style>

This is using the same approach as offered by Damien. It tends to be the only way to accomplish with CSS alone. You can probably better solve this with the use of JavaScript/jQuery.

---

Horizontally aligning things is simple. If the element has a fixed with give it the following css:

.element
{
      margin: 0 auto;
}

This tells the element to have 0 top and bottom marin and auto-calculate the margin to the left and right.

There is a way to vertically center elements called dead center. It uses a 50% off-set from the top of the page and a negative margin to bring the content to the center (vertically). Drawback is that your element needs have a fixed size (height and width).

---

This is what worked for me:

<style type="text/css">
  .auto-style1 {text-align:center;}
</style>