:root {
    --prm-color: #0381ff;
    --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: .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: .5s ease;
}

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

}