.my-back2-2:before { 
                        position: fixed;
                        width: 100%;
                        height: 100%;
                        top: 0px;
                        left: 0px;
                        z-index: 0; 
                    }
                    .my-back2-2:before { 
                        transition: all .7s ease;
                        content: '';
                        background: url("images/uvod/005-color-wide-skoly2.jpg") center top no-repeat;
                        background-attachment: fixed;
                        z-index: -1;                        
                    }
                                @media only screen and (max-width: 640px) {
                                        .my-back2-2:before { 
                                            background: url("images/uvod/005-color-wide-skoly2.jpg") center -60px no-repeat;
                                        }
                                    }