static/css/index.css

 /* Style the tab */
 .tab {
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Style the buttons inside the tab */
.tab button {
    background-color: inherit;
    float: left;
    border: none;
    outline: none;
    cursor: pointer;
    padding: 14px 16px;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of buttons on hover */
.tab button:hover {
    background-color: #ddd;
}

/* Create an active/current tablink class */
.tab button.active {
    background-color: #ccc;
}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}

#progress-container {
    width: 100%;
    background-color: #f3f3f3;
}
#progress-bar {
    width: 0%;
    height: 30px;
    background-color: #4caf50;
    text-align: center;
    line-height: 30px;
    color: white;
}