php and css tag cloud effect

function createTagCloud($tags)
{
    //I pass through an array of tags
    $i=0;
    foreach($tags as $tag)
    {
        $id = $tag['id']; //the tag id, passed through
        $name = $tag['tag']; //the tag name, also passed through in the array

        //using the mysql count command to sum up the tutorials tagged with that id
        $sql = "SELECT COUNT(*) AS totalnum FROM tutorials WHERE tags LIKE '%".$id."%' AND published = 1";

        //create the resultset and return it
        $res = mysql_query($sql);
        $res = mysql_fetch_assoc($res);

        //check there are results ;)
        if($res)
        {
            //build an output array, with the tag-name and the number of results
            $output[$i]['tag'] = $name;
            $output[$i]['num'] = $res['totalnum'];
        }

        $i++;
    }

    /*this is just calling another function that does a similar SQL statement, but returns how many pieces of content I have*/
    $total_tuts = $this->getNumberOfTutorials();

    //ugh, XHTML in PHP?  Slap my hands - this isn't best practice, but I was obviously feeling lazy
    $html = '';  
      
    //iterate through each item in the $output array (created above)  
    foreach($output as $tag)  
    {  
        //get the number-of-tag-occurances as a percentage of the overall number  
        $ratio = (100 / $total_tuts) * $tag['num'];  
          
        //round the number to the nearest 10  
        $ratio =  round($ratio,-1);  
          
        /*append that classname onto the list-item, so if the result was 20%, it comes out as cloud-20*/  
        $html.= ''.$tag['tag'].'';           
    }  
      
    //close the UL  
    $html.= '';

    return $html;
}

2，css代码部分 /*删除默认的列表样式，使之成为一个普通的清单列表*/

.home-item ul.tagcloud
{
    list-style-type:none;
    margin:0px;
    padding:0px;
}

/*设置li的样式*/
.home-item ul.tagcloud li
{
    display:inline !important;
    margin-right:15px;
    line-height:2em;
}

.home-item ul.tagcloud li a
{
    display:inline;
}

/*标签云的效果*/
.home-item ul.tagcloud li.cloud-10 a
{
    font-size:110%;
}

.home-item ul.tagcloud li.cloud-20 a
{
    font-size:120%;
}

.home-item ul.tagcloud li.cloud-30 a
{
    font-size:130%;
}

/*************************************
you get the idea, i'm skipping a few
*************************************/

.home-item ul.tagcloud li.cloud-90 a
{
    font-size:190%;
}

.home-item ul.tagcloud li.cloud-100 a
{
    font-size:200%;
}