Roamfree official website
Your HTML seems to be correct, except you do not have a doctype in there, which goes at the top of the document:

Doctype for HTML5:

&lt;!doctype html&gt;


Your CSS has one error:

li {
    float: center;
}


center is not a possible value for float - only left and right are.

Otherwise, your code has no errors according to the official W3C validators:


  HTML Validator
  CSS Validator


Your HTML markup is, however, very difficult to read due to your wild indentation.  For example, you have this:

&lt;head&gt;
  &lt;style&gt;

...

&lt;/style&gt;
&lt;/head&gt;


Your ending &lt;/style&gt; tag should have the same level of indentation as the beginning tag, and I was taught to use 4 spaces as the indentation level.  Part of the problem is you are mixing tabs and spaces as your indentation level - only use one.

You also have this:

&lt;div class="main"&gt;
    &lt;h1&gt;About Roamfree&lt;/h1&gt;
    &lt;p title="About Roamfree"&gt;
        Roamfree is a small company that wants to be recognised by the internet and we 
        decided to make a website to hold ALL our future products, apps and games!
        This is a Prototype website (not even alpha) so I need support from     
        the online community so my coding skills will progress further and this company     
        will (eventually) grow!&lt;/p&gt;

    &lt;h1&gt;Relyr&lt;/h1&gt;
    &lt;p title="Description"&gt;Well Relyr is the measuring app that I am currently developing
    and it is optimised for iOS 8 and is targeted at the Iphone 5s (sorry Ipad users) 
    and you press Start then you walk with your Iphone with you and afterwards you press
    Stop then using GPS it approximately calculates how far you walked, this is mainly for
    architects and builders but perfectionists can also use it as well :)&lt;/p&gt;
&lt;/div&gt;


Again, the indentation is wild.

Your indentation on the CSS is very good.  However, as your webpage grows, you may find it easier to have the CSS in a different file than the HTML and link to it like this:

&lt;link rel="stylesheet" type="text/css" href="Styles.css"&gt;


If you have multiple designs for different types of media, such as phones, printers, and regular computers, you can set the media tag like this:

&lt;link rel="stylesheet" type="text/css" href="PrintStyles.css" media="print"&gt;