:root {
    --background-color-light: #f0f2f5;
    --container-background-light: white;
    --text-color-light: #333;
    --button-background-light: #008CBA;
    --button-text-light: white;

    --background-color-dark: #121212;
    --container-background-dark: #1e1e1e;
    --text-color-dark: #f0f2f5;
    --button-background-dark: #005f7a;
    --button-text-dark: white;
}

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

body.dark-mode {
    background-color: var(--background-color-dark);
    color: var(--text-color-dark);
}

.container {
    text-align: center;
    background-color: var(--container-background-light);
    padding: 50px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: background-color 0.3s;
}

body.dark-mode .container {
    background-color: var(--container-background-dark);
}

h1 {
    margin-bottom: 40px;
    font-size: 2.5rem;
}

.numbers {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 40px;
}

.number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #4CAF50;
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
}

.generate-btn {
    padding: 15px 40px;
    border: none;
    border-radius: 10px;
    background-color: var(--button-background-light);
    color: var(--button-text-light);
    font-size: 1.2rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

.generate-btn:hover {
    background-color: #007B9A;
}

body.dark-mode .generate-btn {
    background-color: var(--button-background-dark);
    color: var(--button-text-dark);
}

.theme-toggle-btn {
    padding: 10px 20px;
    border: none;
    border-radius: 10px;
    background-color: #ccc;
    color: #333;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s;
    margin-bottom: 20px;
}

.theme-toggle-btn:hover {
    background-color: #bbb;
}

body.dark-mode .theme-toggle-btn {
    background-color: #555;
    color: white;
}