how to Customize Google Search box it is not showing search results?

Hello Everyone this is my first post i have joined this community hoping that my question can be solved i was having a blogger blog but few months ago i regitered it to custom url but now the google search box is not working my visitors are complaining i tried to customize buy the search box is appearing but the results are not appearing can any one give me the html and css code for seach box which match my site theme please.