.tstx_share_btn {
    position: absolute;
    margin: 0 auto;
    width: 215px;
    height: 40px;
    line-height: 40px;
    background-color: #4166b7;
    font-family: HelveticaNeue, Helvetica, Arial, sans-serif;
    font-size: 16px;
    color: #fff;
    text-align: center;
    border-radius: 4px;
    cursor: pointer;
}
.tstx_share_btn.__vk {
    background-color: #5579a2;
}

.tstx_share_i {
    position: absolute;
    top: 10px;
    left: 12px;
    display: block;
    background-image: url(//testix.me/products/common/i/fb-share-icon.png);
    width: 22px;
    height: 20px;
}
.tstx_share_i.__vk {
    background-image: url(//testix.me/products/common/i/vk-share-icon.png);
}

@media (max-width:600px)  {

}

@media (-webkit-min-device-pixel-ratio: 1.5), (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi), (min-resolution: 1.5dppx) {
    .tstx_share_i {
        background-image: url(//testix.me/products/common/i/fb-share-icon@2x.png);
        background-size: 22px 20px;
    }
    .tstx_share_i.__vk {
        background-image: url(//testix.me/products/common/i/vk-share-icon@2x.png);
        background-size: 22px 20px;
    }
}