:root {
    --prm-color: #28a745;
    --prm-gray: #b1b1b1;
}

/*  unnecessary finished*/

/* CSS */
.steps {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    position: relative;
}

.step-button {
    width: 35px;
    height: 35px;
    border-radius: 50%;
    border: none;
    background-color: var(--prm-gray);
    transition: .4s;
}

    .step-button[aria-expanded="true"] {
        width: 35px;
        height: 35px;
        background-color: var(--prm-color);
        color: #fff;
    }

.done {
    background-color: var(--prm-color);
    color: #fff;
}

.step-item {
    z-index: 10;
    text-align: center;
    width: 120px;
}
.step-title{
    height:48px;
}
#progress {
    -webkit-appearance: none;
    position: absolute;
    width: 90%;
    z-index: 5;
    height: 10px;
    margin-left: 55px;
    margin-bottom: -50px;
}

    /* to customize progress bar */
    #progress::-webkit-progress-value {
        background-color: var(--prm-color);
        transition: .5s ease;
    }

    #progress::-webkit-progress-bar {
        background-color: var(--prm-gray);
    }