.border-style-disappear{

    border-image: linear-gradient (to bottom, grey, #f5f5f5) 1 100%;
    -moz-border-image: -moz-linear-gradient(grey, #f5f5f5) 1 100%; 
    -webkit-border-image: -webkit-gradient(linear, 0 0, 0 100%, from(grey), to(#f5f5f5)) 1 100%; 
    -webkit-border-image: -webkit-linear-gradient(grey, #f5f5f5) 1 100%; 
    -o-border-image: -o-linear-gradient(grey, #f5f5f5) 1 100%;
}