* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f4f4f4;
}

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

nav a {
    color: white;
    text-decoration: none;
    margin: 0 15px;
    padding: 5px 10px;
    border-radius: 3px;
    transition: background 0.3s;
}

nav a:hover {
    background: #555;
}

main {
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 20px;
}

section {
    background: white;
    margin: 2rem 0;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

button {
    background: #007cba;
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    margin: 10px 0;
}

button:hover {
    background: #005a87;
}

#message {
    margin-top: 15px;
    padding: 10px;
    background: #e8f5e8;
    border-radius: 4px;
    display: none;
}