html, body {
    height: 100%;
    margin: 0;
}

body {
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
}

header {
    background-color: #4CAF50;
    color: white;
    padding: 10px 0;
    text-align: center;
    width: 100%;
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.video-gallery {
    display: block; 
    margin: 20px;
    width: 100%; 
    max-width: 800px;
}

.video {
    width: 100%; 
    margin: 15px 0; 
    border: 1px solid #ddd;
    padding: 10px;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

iframe {
    width: 100%;
    height: 400px; 
    border: none;
}

footer {
    text-align: center;
    padding: 15px 0;
    background-color: #f1f1f1;
    width: 100%;
}

#backToTop {
    position: fixed;
    bottom: 20px;
    right: 20px;
    display: none; 
    background: #007BFF;
    color: white;
    padding: 10px 15px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}