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

button {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 10px;
    font-size: 16px;
    cursor: pointer;
    border-radius: 50%;
    background-color: #333;
    color: white;
    border: none;
}

header {
    background-color: #333;
    padding: 10px;
    text-align: center;
    color: white;
}

nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    background-color: #555;
    padding: 10px;
}

nav a {
    color: white;
    text-decoration: none;
    padding: 10px 20px;
    margin: 5px;
    display: inline-block;
    border: 1px solid #fff;
    border-radius: 5px;
    transition: background-color 0.3s;
}

nav a:hover {
    background-color: #777;
}

.gallery {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
}

.gallery img {
    width: 100%;
    max-width: 800px;
    height: auto;
    margin-bottom: 20px;
    box-sizing: border-box;
}

footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 20px 10px;
    width: 100%;
    position: relative;
}

footer a {
    color: white;
}