:root {
    --bg-color: #f0f0f0;
    --container-bg: white;
    --text-color: #333;
    --button-bg: #007bff;
    --button-hover-bg: #0056b3;
    --number-bg: #4CAF50;
    --number-text: white;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

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);
    margin: 0;
    transition: background-color 0.3s, color 0.3s;
}

body.dark-mode {
    --bg-color: #333;
    --container-bg: #444;
    --text-color: #f0f0f0;
    --button-bg: #555;
    --button-hover-bg: #777;
    --number-bg: #888;
    --shadow-color: rgba(255, 255, 255, 0.1);
}

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

.numbers-container {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
}

.number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--number-bg);
    color: var(--number-text);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
}

#generate-btn {
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    background-color: var(--button-bg);
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#generate-btn:hover {
    background-color: var(--button-hover-bg);
}

#theme-toggle-btn {
    margin-top: 1rem;
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    background-color: var(--button-bg);
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#theme-toggle-btn:hover {
    background-color: var(--button-hover-bg);
}