.teksti{font-size:2em;
width:480px; 
    height:100px; 
    position:absolute; 
    left:50%;
    top:50%; 
    margin-left:-240px; 
    margin-top:110px;  
    color:#ffffff; 
    text-align:center; 
    font-family: 'Roboto', sans-serif; 
    font-weight: 100;}

   @media only screen 
  and (min-device-width: 320px) 
  and (max-device-width: 480px)
  and (-webkit-min-device-pixel-ratio: 2) {
       .teksti{font-size:4.2em;
        font-weight: 400;}

}