:root {
    --bg: #f0f0f0;
    --text: #222;
    --number-bg: #fff;
    --number-border: #ccc;
    --number-text: #222;
    --toggle-bg: #555;
    --toggle-text: #fff;
}

body.dark {
    --bg: #1a1a2e;
    --text: #e0e0e0;
    --number-bg: #2d2d44;
    --number-border: #555;
    --number-text: #e0e0e0;
    --toggle-bg: #e0e0e0;
    --toggle-text: #1a1a2e;
}

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

#theme-toggle {
    position: fixed;
    top: 16px;
    right: 16px;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: none;
    background-color: var(--toggle-bg);
    color: var(--toggle-text);
    font-size: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s;
}

.container {
    text-align: center;
}

.numbers-container {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
}

.number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--number-bg);
    border: 2px solid var(--number-border);
    color: var(--number-text);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    margin: 0 5px;
    transition: background-color 0.3s, border-color 0.3s, color 0.3s;
}

#generate-btn {
    padding: 10px 20px;
    font-size: 18px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}