body {
    font-family: Arial, sans-serif;
    background: #0f172a;
    color: white;
    text-align: center;
    padding: 40px;
}

h2 {
    margin-bottom: 20px;
}

.container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    max-width: 800px;
    margin: auto;
}

button {
    padding: 12px;
    border: none;
    border-radius: 10px;
    background: #1e293b;
    color: white;
    cursor: pointer;
    transition: 0.3s;
    font-size: 14px;
}

button:hover {
    background: #38bdf8;
    color: black;
}

#error {
    margin-top: 20px;
    color: #f87171;
    font-weight: bold;
}