```css
* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    line-height: 1.6;
    color: #333;
}

.container {
    width: 80%;
    margin: 0 auto;
    max-width: 1200px;
}

header {
    background-color: #1a3c34;
    color: #fff;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

header h1 {
    margin: 0;
    font-size: 2rem;
    display: inline-block;
}

header nav {
    float: right;
    margin-top: 0.5rem;
}

header nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

header nav ul li {
    display: inline;
    margin-left: 1.5rem;
}

header nav ul li a {
    color: #fff;
    text-decoration: none;
    font-size: 1.1rem;
}

header nav ul li a:hover {
    text-decoration: underline;
}

main {
    padding: 2rem 0;
}

section {
    padding: 3rem 0;
    text-align: center;
}

section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #1a3c34;
}

section p, section ul {
    font-size: 1.2rem;
    color: #555;
    margin: 0.5rem 0;
}

section ul {
    list-style: none;
    padding: 0;
}

section ul li {
    margin: 0.5rem 0;
    font-size: 1.1rem;
}

form {
    max-width: 600px;
    margin: 2rem auto;
    text-align: left;
}

form label {
    display: block;
    margin: 0.5rem 0 0.2rem;
    font-weight: bold;
}

form input, form textarea {
    width: 100%;
    padding: 0.8rem;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

form textarea {
    height: 150px;
    resize: vertical;
}

form button {
    background-color: #1a3c34;
    color: #fff;
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 4px;
    font-size: 1.1rem;
    cursor: pointer;
}

form button:hover {
    background-color: #15524a;
}

footer {
    background-color: #f4f4f4;
    padding: 2rem 0;
    border-top: 1px solid #ddd;
    text-align: center;
}

.footer-info p {
    margin: 0.5rem 0;
    font-size: 1rem;
}

@media (max-width: 768px) {
    header h1 {
        display: block;
        text-align: center;
    }

    header nav {
        float: none;
        text-align: center;
        margin-top: 1rem;
    }

    header nav ul li {
        display: block;
        margin: 0.5rem 0;
    }

    .container {
        width: 90%;
    }

    section h2 {
        font-size: 2rem;
    }

    section p, section ul li {
        font-size: 1rem;
    }
}
```