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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #333;
}

.container {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    max-width: 600px;
    width: 90%;
}

h1 {
    color: #667eea;
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1rem;
    color: #666;
}

.demo-section {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid #eee;
}

button {
    background: #667eea;
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s ease;
}

button:hover {
    background: #764ba2;
}

#message {
    margin-top: 1rem;
    font-weight: bold;
    color: #667eea;
}