body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: #f9f9f9;
}

.dfePage {
  display: flex;
  flex-direction: column;
  gap: 30px;
  align-items: center;
}

.container {
    background: #ffffff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    text-align: center;
    width: 80%;
    max-width: 400px;
}

.button-group {
    margin-top: 20px;
}

button {
    padding: 10px 20px;
    margin: 0 10px;
    border: 1px solid #cccccc;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    background-color: #e7e7e7;
    color: #333333;
    transition: background-color 0.3s, color 0.3s;
}

button.ok {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

button.cancel {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

button.ok:hover {
    background-color: #c3e6cb;
    color: #0c3d12;
}

button.cancel:hover {
    background-color: #f5c6cb;
    color: #5a1e23;
}

button:hover {
    opacity: 0.9;
}

button.ok:disabled {
    opacity: 0.6;
    position: relative;
}

button.ok:disabled::after {
    content: "Use uppercase letters separated by a dash.";
    position: absolute;
    bottom: 90%;
    left: 50%;
    transform: translateX(-50%);
    background-color: rgba(0, 0, 0, 0.9);
    color: #fff;
    padding: 6px 10px;
    border-radius: 4px;
    white-space: nowrap;
    font-size: 12px;
    visibility: hidden;
    opacity: 0;
    transition: opacity 0.2s ease-in-out;
}

button.ok:disabled:hover::after {
    visibility: visible;
    opacity: 1;
}

#message strong {
    font-weight: bold;
}

#spinner {
    display: none;
    border: 4px solid #f3f3f3;
    border-top: 4px solid #3498db;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.hidden {
    display: none;
}