:root {
    --bg-color: #f0f2f5;
    --container-bg: #fff;
    --text-color: #333;
    --number-bg: #4CAF50;
    --btn-bg: #007bff;
    --btn-hover: #0056b3;
}

[data-theme="dark"] {
    --bg-color: #18191a;
    --container-bg: #242526;
    --text-color: #e4e6eb;
    --number-bg: #2e7d32;
    --btn-bg: #3a3b3c;
    --btn-hover: #4e4f50;
}

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

.container {
    text-align: center;
    background-color: var(--container-bg);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    transition: background-color 0.3s;
}

.theme-toggle {
    text-align: right;
    margin-bottom: 20px;
}

#theme-toggle-btn {
    background-color: transparent;
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 5px 10px;
    font-size: 14px;
    border-radius: 5px;
    cursor: pointer;
}

h1 {
    color: var(--text-color);
    margin-bottom: 30px;
}

.numbers {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 30px;
}

.number {
    width: 60px;
    height: 60px;
    background-color: var(--number-bg);
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    font-weight: bold;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

button#generate {
    background-color: var(--btn-bg);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 18px;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

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