:root {
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-color: #333333;
    --shadow: 0 10px 20px rgba(0,0,0,0.1);
    --button-bg: #007bff;
    --button-hover: #0056b3;
}

:root.dark-mode {
    --bg-color: #1a1a1a;
    --card-bg: #2d2d2d;
    --text-color: #f0f2f5;
    --shadow: 0 10px 20px rgba(0,0,0,0.5);
    --button-bg: #375a7f;
    --button-hover: #2b4764;
}

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

h1 {
    color: var(--text-color);
    margin-bottom: 2rem;
}

lotto-generator {
    display: block;
    text-align: center;
    padding: 2rem;
    background-color: var(--card-bg);
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: background-color 0.3s, box-shadow 0.3s;
}

.theme-toggle {
    position: fixed;
    top: 1rem;
    right: 1rem;
    padding: 0.5rem 1rem;
    border-radius: 20px;
}

button {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    color: #fff;
    background-color: var(--button-bg);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: var(--button-hover);
}

/* Color styles for numbers */
.number[data-color="yellow"] { background-color: #fbc400; }
.number[data-color="blue"] { background-color: #69c8f2; }
.number[data-color="red"] { background-color: #ff7272; }
.number[data-color="gray"] { background-color: #aaaaaa; }
.number[data-color="green"] { background-color: #b0d840; }