/* Reset default margins and padding */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: #f4f4f9;
    color: #333;
    line-height: 1.6;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

h1 {
    font-size: 2rem;
    color: #2c3e50;
    margin-bottom: 20px;
    text-align: center;
}

h2 {
    font-size: 1.5rem;
    color: #34495e;
    margin-top: 20px;
    margin-bottom: 10px;
}

p {
    font-size: 1rem;
    margin-bottom: 15px;
}

a {
    color: #007AFF;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.back-to-top {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 10px 15px;
    background-color: #333;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
}

.back-to-top:hover {
    background-color: #555;
}

@media (max-width: 600px) {
    .container {
        margin: 20px;
        padding: 15px;
    }

    h1 {
        font-size: 1.5rem;
    }

    h2 {
        font-size: 1.2rem;
    }

    p {
        font-size: 0.9rem;
    }
}