body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #1a1a1a;
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}
.container {
    text-align: center;
    padding: 2rem;
    border: 2px solid #00ff88;
    border-radius: 15px;
    background: #2a2a2a;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}
button {
    background-color: #00ff88;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
    margin-top: 15px;
}
button:hover {
    background-color: #00cc6e;
}