body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #333;
    color: #fff;
    padding: 1rem;
    text-align: center;
}

nav ul {
    list-style: none;
    padding: 0;
    display: flex;
    justify-content: center;
    margin: 0;
}

nav li {
    margin: 0 1rem;
    cursor: pointer;
}

nav li:hover {
    text-decoration: underline;
}

#video-gallery {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    padding: 1rem;
}

.video-item {
    margin: 1rem;
    width: 300px;
    text-align: center;
}

video {
    width: 100%;
    height: auto;
}