:root {
    /*    --prm-color: #0381ff;*/
    --prm-color: #75F5B7;
    --prm-gray: #b1b1b1;
}
/*  unnecessary */
/*body {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: space-evenly;
    flex-direction: column;
}

section {
    width: 100%;
}*/
/*  unnecessary finished*/

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

.step-button {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: none;
    background-color: var(--prm-gray);
    transition: 0.4s;
}

    .step-button[aria-expanded="true"] {
        width: 60px;
        height: 60px;
        background-color: var(--prm-color);
        color: #fff;
    }

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

.step-item {
    z-index: 10;
    text-align: center;
}

#progress {
    -webkit-appearance: none;
    position: absolute;
    width: 95%;
    z-index: 5;
    height: 10px;
    margin-left: 18px;
    margin-bottom: 18px;
}

    /* to customize progress bar */
    #progress::-webkit-progress-value {
        background-color: var(--prm-color);
        transition: 0.5s ease;
    }

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

/*a {
    background-color: #ffff0047;
}
*/