:root {
    --bg-color: #f0f0f0;
    --text-color: #333;
    --container-bg: #fff;
    --btn-bg: #4CAF50;
    --btn-text: white;
}

body.dark-mode {
    --bg-color: #1a1a1a;
    --text-color: #f0f0f0;
    --container-bg: #2d2d2d;
    --btn-bg: #45a049;
    --btn-text: #fff;
}

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;
}

.container {
    text-align: center;
    padding: 30px;
    background-color: var(--container-bg);
    border-radius: 15px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 8px 15px;
    cursor: pointer;
    border: 1px solid var(--text-color);
    border-radius: 20px;
    background: transparent;
    color: var(--text-color);
    font-size: 0.9rem;
}

button#generate {
    padding: 10px 20px;
    font-size: 1.2rem;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    background-color: var(--btn-bg);
    color: var(--btn-text);
    margin-bottom: 20px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.numbers-container {
    display: flex;
    gap: 10px;
}

.number-ball {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 1.5rem;
    font-weight: bold;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}