body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #121212; /* Dark mode background */
    color: #fff; /* Dark mode text color */
    transition: background-color 0.3s, color 0.3s;
}

.container {
    text-align: center;
}

.center {
    display: block;
    margin: 10px auto;
}

.top-right {
    position: absolute;
    top: 10px;
    right: 10px;
}

.hidden {
    display: none;
}

.dark-mode {
    background-color: #121212;
    color: #fff;
}

.light-mode {
    background-color: #f0f0f0;
    color: #000;
}

button {
    padding: 10px 20px;
    margin: 5px;
    cursor: pointer;
}

input, textarea {
    padding: 10px;
    margin: 5px;
    width: calc(100% - 30px);
    box-sizing: border-box;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 10px;
    padding: 10px;
}

.grid-item {
    background-color: #333;
    padding: 15px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    transition: 0.3s;
}

.grid-item:hover {
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
}

.grid-item-light {
    background-color: #fff;
    color: #000;
}

.grid-item-dark {
    background-color: #333;
    color: #fff;
}