body{
  font-family: Open Sans
}
.content_box { 
    padding:5px; 
    width:300px; 
    float:left;
    height:250px; 
    border:#00FFFF solid 1px; 
    margin:10px;
    overflow:auto;
    color:#999999;
    font-size:14px;
  }
  
  .content_holder_box{ width:300px;
    float:right;
    height: 250px;
    border:#0099FF solid 1px;
    padding:10px;
    margin:10px;
    color:#999999;
    font-size:14px;
  }
  
  .content_holder_box:hover{ 
    border:#0099FF solid 1px; 
  }
  
  
  .dragelement{ 
    padding:5px; 
    margin:3px; 
    width:270px; 
    border:#99FF66 solid 1px;
    background-color:#E2FFC6;
    cursor:move;
    color:#000;
    font-size:13px;
  }
  
  .dropper{ width:270px;
    height:125px;
    margin:10px;
    
  }
  
  .dropper_hover{ 
    border:#999999 dashed 1px; 
    background:url(../images/darrow.jpg) center no-repeat;
  }
  
  //you can show arrow image to suggest where user has to drop selected UI.