.topnav {
    overflow: hidden;
    background-color: #333;
}

.topnav a {
    float: left;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
}

.topnav a:hover {
    background-color: #ddd;
    color: black;
}

.topnav a.active {
    background-color: #555;
    color: white;
}

body {
    box-sizing: border-box;
    background-color: Black;
    padding: 20px;
    font-family: "Arial", serif;
}

/* Center website */
.main-width {
    max-width: 1200px;
    margin: auto;
}

/* Wrapper for multiple containers */
.wrapper {
    display: flex;
    flex-wrap: wrap;        /* allows multiple rows */
    gap: 20px;              /* spacing between containers */
    justify-content: center;
}

div.scroll-container {
    background-color: #333;
    overflow: auto;
    white-space: nowrap;
    padding: 10px;
    justify-content:center;
}

div.scroll-container img {
    padding: 10px;
}

/* Expanding image text */
#imgtext {
    position: absolute;
    bottom: 15px;
    left: 15px;
    color: white;
    font-size: 20px;
}

/* Close button */
#closeBtn {
    position: absolute;
    top: 20px;
    right: 20px;
    background: #fff;
    border: none;
    padding: 10px 15px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
}

/* Style the footer */
footer {
    background-color: #777;
    padding: 10px;
    text-align: center;
    color: white;
}

#ScrollupBtn {
    display: none; /* Hidden by default */
    position: fixed; /* Fixed/sticky position */
    bottom: 20px; /* Place the button at the bottom of the page */
    right: 30px; /* Place the button 30px from the right */
    z-index: 99; /* Make sure it does not overlap */
    border: none; /* Remove borders */
    outline: none; /* Remove outline */
    background-color: red; /* Set a background color */
    color: white; /* Text color */
    cursor: pointer; /* Add a mouse pointer on hover */
    padding: 15px; /* Some padding */
    border-radius: 10px; /* Rounded corners */
    font-size: 18px; /* Increase font size */
}

#ScrollupBtn:hover {
    background-color: #555; /* Add a dark-grey background on hover */
}