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

[data-theme="dark"] {
    --background-color: #333;
    --container-background: #444;
    --text-color: #f0f0f0;
    --number-background: #555;
    --button-background: #5cb85c;
    --button-text: #333;
}

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

#theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background-color: var(--button-background);
    color: var(--button-text);
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
}

.container {
    background-color: var(--container-background);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    text-align: center;
}

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

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

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