:root {
    --bg-color: #f0f2f5;
    --container-bg: #ffffff;
    --text-color: #333333;
    --btn-bg: #007bff;
    --btn-text: #ffffff;
    --number-bg: #f0f0f0;
    --number-text: #333333;
    --shadow: rgba(0, 0, 0, 0.1);
}

body.dark-mode {
    --bg-color: #18191a;
    --container-bg: #242526;
    --text-color: #e4e6eb;
    --btn-bg: #3a3b3c;
    --btn-text: #e4e6eb;
    --number-bg: #3a3b3c;
    --number-text: #e4e6eb;
    --shadow: rgba(0, 0, 0, 0.5);
}

body {
    font-family: 'Arial', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
}

.container {
    text-align: center;
    padding: 2rem;
    background-color: var(--container-bg);
    border-radius: 10px;
    box-shadow: 0 4px 8px var(--shadow);
    transition: background-color 0.3s, box-shadow 0.3s;
}

#theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 0.5rem 1rem;
    cursor: pointer;
    border: 1px solid var(--text-color);
    border-radius: 5px;
    background-color: var(--container-bg);
    color: var(--text-color);
}

#generate-btn {
    margin-top: 1rem;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    background-color: var(--btn-bg);
    color: var(--btn-text);
}

.numbers-container {
    display: flex;
    justify-content: center;
    margin-top: 1.5rem;
}

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