:root {
    --bg-color: #f0f0f0;
    --text-color: #333;
    --container-bg: #fff;
    --button-bg: #4a90e2;
    --button-text: #fff;
    --number-bg: #eee;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #f0f0f0;
    --container-bg: #2d2d2d;
    --button-bg: #357abd;
    --button-text: #fff;
    --number-bg: #444;
}

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

.container {
    text-align: center;
    padding: 2rem;
    background-color: var(--container-bg);
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: background-color 0.3s;
}

#theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 8px 16px;
    cursor: pointer;
    border-radius: 20px;
    border: 1px solid var(--text-color);
    background: transparent;
    color: var(--text-color);
    font-weight: bold;
    transition: all 0.3s;
}

#generate {
    padding: 12px 24px;
    font-size: 1.1rem;
    cursor: pointer;
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    border-radius: 6px;
    margin-top: 1rem;
    transition: background-color 0.3s;
}

#generate:hover {
    opacity: 0.9;
}

#numbers {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 30px;
}

.number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--number-bg);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.2rem;
    font-weight: bold;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}