.file-upload {
    position: relative;
    overflow: hidden;
}
.file-upload .file-input {
    position: absolute;
    top: 0;
    right: 0;
    left: 0;
    opacity: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
    font-size: 0;
}