body {
    background-image: url('../../assets/img/bg_main.gif');
}

.center_div {
    margin: 0 auto;
    width: 80% /* value of your choice which suits your alignment */
}

.container {
    position: relative;
    margin-top: 30px;
}

.form {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
}

.table-head-bg-success thead th, .table-striped-bg-success tbody tr:nth-of-type(odd) {
    background: #0d6310 !important;
}

.btn-success {
    background: #0d6310 !important;
}

    .btn-success:hover, .btn-success:focus, .btn-success:disabled {
        background: #0d6310 !important;
    }