<linearGradient id="grad" x1="0" x2="0" y1="0" y2="1">y2 заменить значение с 1 на 100%:<linearGradient id="grad" x1="0" x2="0" y1="0" y2="100%">gradientUnits со значением userSpaceOnUse:<linearGradient id="grad" x1="0" x2="0" y1="0" y2="100%" gradientUnits="userSpaceOnUse">gradientUnits.
background-color: #000000;
background-image: url(http://30r.biz/images/st/gol/jk/25%D1%8525/JapKros-Lico-25x25.png);
background-repeat: no-repeat;
background-position: center;