body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #f4f4f4;
    transition: background 0.5s ease-in-out, color 0.5s ease-in-out;
}

.container {
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0px 4px 10px rgba(0, 0, 0, 0.2);
    text-align: center;
    transition: background 0.5s ease-in-out, color 0.5s ease-in-out;
}

.form-group {
    margin-bottom: 15px;
    text-align: left;
}

input {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
    border: 1px solid #ccc;
    border-radius: 5px;
    transition: background 0.3s, color 0.3s;
}

.error {
    color: red;
    font-size: 12px;
}

button {
    padding: 10px 15px;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.3s;
}

button:hover {
    background: #218838;
}

/* Dark Mode */
.dark-mode {
    background: #222;
    color: white;
}

.dark-mode .container {
    background: #333;
}

.dark-mode input {
    background: #555;
    color: white;
}

.dark-mode button {
    background: #007bff;
}

.dark-mode button:hover {
    background: #0056b3;
}

/* Smooth Transition for Dark Mode */
body, .container, input, button {
    transition: background 0.5s ease, color 0.5s ease;
}