placeholder.css

/* BEGIN OF RESPONSIVE PLACEHOLDER CLASS */

/**
 placeholder-xs class to show placeholder with field name for mobile phones but to hide and show label instead on larger screens.
 Media for bigger devices than phones (tablet, laptops larger than 767px)
*/
@media (min-width: 768px) {
    .placeholder-xs::-webkit-input-placeholder { /* Chrome */
        color: transparent;
    }
    .placeholder-xs:-ms-input-placeholder { /* IE 10+ */
        color: transparent;
    }
    .placeholder-xs::-moz-placeholder { /* Firefox 19+ */
        color: transparent;
    }
    .placeholder-xs:-moz-placeholder { /* Firefox 4 - 18 */
        color: transparent;
    }
}
/* END OF RESPONSIVE PLACEHOLDER CLASS */