:root {
    --bg-color: #f0f0f0;
    --container-bg-color: white;
    --text-color: #000;
    --box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    --number-bg-color: #ddd;
}

body {
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
}

body.dark-mode {
    --bg-color: #2c2c2c;
    --container-bg-color: #3b3b3b;
    --text-color: #f0f0f0;
    --box-shadow: 0 0 10px rgba(255, 255, 255, 0.1);
    --number-bg-color: #555;
}

#theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    cursor: pointer;
    border: 1px solid var(--text-color);
    background-color: transparent;
    color: var(--text-color);
    border-radius: 5px;
}

.container {
    text-align: center;
    background-color: var(--container-bg-color);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
}

button#generator {
    margin-top: 1rem;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    cursor: pointer;
    border: none;
    background-color: #4CAF50;
    color: white;
    border-radius: 5px;
}

.numbers-container {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
}

.number {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--number-bg-color);
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0 0.5rem;
    font-size: 1.2rem;
    font-weight: bold;
}