body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f9;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    width: 300px;
    text-align: center;
}

input {
    padding: 10px;
    width: 60%;
    margin-bottom: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

button {
    padding: 10px 15px;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

button:hover {
    background-color: #218838;
}

.result-box {
    margin-top: 20px;
    text-align: left;
    background: #e9ecef;
    padding: 10px;
    border-radius: 4px;
}

.error-box {
    margin-top: 20px;
    color: red;
    font-weight: bold;
}