some quick search classes

Search:
Class/ID = “.s4-search table”
Default CSS: 
width: 212px;
margin-right: 17px;  
Comments: This is the container for the search box. The class resides in the Search.css file.

Look at the link

http://share-sharepoint2010.bl…..ol-in.html

Some more classes

Search Input:
Class/ID = “.s4-search input”
Default CSS: 
width: 212px;
margin-right: 17px;  
Comments: Note that this class does not change width, border color or height. You could use this to change the background color.

Search Image:
Class/ID = “.s4-search .ms-searchimage”
Default CSS: 
background-color:#fff;
border:1px solid #e3e3e3 !important;
height:16px;
padding:2px 3px 1px;
border-left:none !important;
margin-top:3px;  
Comments: This class controls the border around the go image.