html,
body {
    height: 100%;
    width: 100%;
}

.container {
    height: 100%;
}

.info_box,
.quiz_box {
    width: 75%;
    background: #FFD400;
}

.time_line {
    display: none;
}

.error {
    font-size: 12px;
    color: red
}

.bg {
    /* The image used */
    background: #ffd400;
    background-image: url("shell-bg-desktop-contain.webp");
    /* Full height */
    height: 100%;
    /* Center and scale the image nicely */
    background-position: center;
    background-repeat: no-repeat;
    background-size: contain;
}

.bg2 {
    /* The image used 
    background-image: url("bg-shell.webp");*/
    /* Full height */
    height: 100%;
    /* Center and scale the image nicely */
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}

@media only screen and (max-width: 750px) {
    .info_box,
    .quiz_box {
        width: 90%;
    }
    .time_line {
        display: block;
    }
    .bg {
        /* The image used */
        background: #ffd400;
        background-image: url("shell-bg-mobile-2.webp");
        /* Full height */
        height: 100%;
        /* Center and scale the image nicely */
        background-position: center;
        background-repeat: no-repeat;
        background-size: contain;
    }
    .bg2 {
        /* The image used */
        background: #ba1c16;
       /* background-image: url("bg-shell-mobile.webp");*/
        /* Full height */
        height: 100%;
        /* Center and scale the image nicely */
        background-position: center;
        background-repeat: no-repeat;
        background-size: cover;
    }
}