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

[data-theme='dark'] {
    --bg-color: #1a1a1a;
    --container-bg: #2d2d2d;
    --text-color: #f0f0f0;
    --number-bg: #444;
    --number-text: #fff;
    --btn-bg: #45a049;
    --btn-text: #fff;
}

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

.container {
    background-color: var(--container-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
    text-align: center;
    position: relative;
    transition: background-color 0.3s;
}

.theme-toggle {
    position: absolute;
    top: 10px;
    right: 10px;
    cursor: pointer;
    background: none;
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 0.8rem;
}

.numbers-container {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
    flex-wrap: wrap;
    gap: 10px;
}

.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;
    transition: background-color 0.3s, color 0.3s;
}

#generate-btn {
    margin-top: 2rem;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    border: none;
    border-radius: 5px;
    background-color: var(--btn-bg);
    color: var(--btn-text);
    cursor: pointer;
    transition: background-color 0.3s;
}

#generate-btn:hover {
    opacity: 0.9;
}