body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #111827;
    color: #f3f4f6;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background: #1f2937;
    padding: 2rem;
    border-radius: 12px;
    width: min(500px, 90vw);
    text-align: center;
    box-shadow: 0 10px 30px rgba(0,0,0,0.4);
}

h1 {
    margin-top: 0;
}

button {
    background: #2563eb;
    color: white;
    border: none;
    padding: 0.8rem 1.4rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
}

button:hover {
    background: #1d4ed8;
}

pre {
    margin-top: 1rem;
    background: #0f172a;
    padding: 1rem;
    border-radius: 8px;
    text-align: left;
    overflow-x: auto;
}