body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.login-container {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
    text-align: center;
}

h2 {
    color: #075e54; /* WhatsApp Green */
    margin-bottom: 1.5rem;
}

input[type="text"] {
    width: 100%;
    padding: 12px;
    margin: 10px 0;
    box-sizing: border-box;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 16px;
}

button {
    width: 100%;
    padding: 12px;
    background-color: #25d366;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    font-weight: bold;
    margin-top: 10px;
}

button:hover {
    background-color: #128c7e;
}

button.secondary {
    background-color: #ccc;
    color: #333;
}

button.secondary:hover {
    background-color: #bbb;
}

.message {
    margin-top: 15px;
    font-size: 14px;
}

.message.error {
    color: red;
}

.message.success {
    color: green;
}