:root {
    --bg-color-dark: #1a1a1a;
    --bg-color-light: #f0f2f5;
    --container-bg-dark: #2a2a2a;
    --container-bg-light: #ffffff;
    --text-color-dark: #fff;
    --text-color-light: #333;
    --h1-shadow-dark: rgba(255, 255, 255, 0.3);
    --h1-shadow-light: rgba(0, 0, 0, 0.2);
    --container-shadow-dark: 0 10px 30px rgba(0, 0, 0, 0.5), 0 0 100px rgba(255, 255, 255, 0.1);
    --container-shadow-light: 0 10px 30px rgba(0, 0, 0, 0.1), 0 0 50px rgba(0, 0, 0, 0.05);
    --number-shadow-dark: inset 0 0 10px rgba(0,0,0,0.5);
    --number-shadow-light: inset 0 0 10px rgba(200,200,200,0.3);
    --number-hover-shadow-dark: inset 0 0 10px rgba(0,0,0,0.5), 0 0 20px rgba(255,255,255,0.3);
    --number-hover-shadow-light: inset 0 0 10px rgba(200,200,200,0.3), 0 0 20px rgba(0,0,0,0.1);

    /* Initial theme (dark mode) */
    --bg-primary: var(--bg-color-dark);
    --container-bg: var(--container-bg-dark);
    --text-primary: var(--text-color-dark);
    --h1-text-shadow: var(--h1-shadow-dark);
    --container-box-shadow: var(--container-shadow-dark);
    --number-box-shadow: var(--number-shadow-dark);
    --number-hover-box-shadow: var(--number-hover-shadow-dark);
    --body-bg-image: radial-gradient(circle, #333, #1a1a1a 70%);
}

.light-mode {
    --bg-primary: var(--bg-color-light);
    --container-bg: var(--container-bg-light);
    --text-primary: var(--text-color-light);
    --h1-text-shadow: var(--h1-shadow-light);
    --container-box-shadow: var(--container-shadow-light);
    --number-box-shadow: var(--number-shadow-light);
    --number-hover-box-shadow: var(--number-hover-box-shadow);
    --body-bg-image: radial-gradient(circle, #d0d5db, #f0f2f5 70%);
}

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

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

h1 {
    font-size: 3em;
    margin-bottom: 20px;
    text-shadow: 0 0 10px var(--h1-text-shadow);
    transition: text-shadow 0.3s ease;
}

.numbers-container {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.number {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.8em;
    font-weight: bold;
    color: #fff; /* Lotto numbers always white text for contrast */
    box-shadow: var(--number-box-shadow);
    text-shadow: 0 0 5px rgba(0,0,0,0.5);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.number:hover {
    transform: scale(1.1);
    box-shadow: var(--number-hover-box-shadow);
}

#generate-button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1.2em;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

#generate-button:hover {
    background-color: #45a049;
    transform: translateY(-2px);
}

#generate-button:active {
    transform: translateY(1px);
}

/* Theme Toggle Button Styles */
.theme-toggle-button {
    background-color: #6c757d;
    color: white;
    border: none;
    padding: 8px 15px;
    font-size: 0.9em;
    border-radius: 5px;
    cursor: pointer;
    margin-bottom: 20px;
    transition: background-color 0.3s ease, transform 0.2s ease;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.theme-toggle-button:hover {
    background-color: #5a6268;
    transform: translateY(-1px);
}

@media (max-width: 600px) {
    .container {
        padding: 20px;
    }

    h1 {
        font-size: 2em;
    }

    .number {
        width: 50px;
        height: 50px;
        font-size: 1.5em;
    }
}