:root {
    --bg: #f0f0f0;
    --text: #333;
    --container-bg: #fff;
    --number-bg: #eee;
    --button-bg: #4CAF50;
    --button-hover-bg: #45a049;
    --footer-text: #888;
    --toggle-bg: #333;
    --toggle-text: #fff;
}

body[data-theme="dark"] {
    --bg: #111827;
    --text: #f3f4f6;
    --container-bg: #1f2937;
    --number-bg: #374151;
    --button-bg: #22c55e;
    --button-hover-bg: #16a34a;
    --footer-text: #9ca3af;
    --toggle-bg: #f3f4f6;
    --toggle-text: #111827;
}

body {
    font-family: sans-serif;
    background-color: var(--bg);
    color: var(--text);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background-color 0.2s, color 0.2s;
}

.container {
    background-color: var(--container-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: background-color 0.2s;
}

h1 {
    color: var(--text);
    margin-bottom: 1.5rem;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.number-display {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.number {
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    background-color: var(--number-bg);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text);
    transition: background-color 0.2s, color 0.2s;
}

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

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

#theme-toggle-btn {
    background-color: var(--toggle-bg);
    color: var(--toggle-text);
    border: none;
    border-radius: 0.5rem;
    padding: 0.5rem 0.8rem;
    cursor: pointer;
    font-size: 0.9rem;
}

footer {
    margin-top: 2rem;
    font-size: 0.8rem;
    color: var(--footer-text);
}