:root {
    --primary-color: #4a90e2;
    --background-color: #f0f4f8;
    --text-color: #333;
    --white: #fff;
    --shadow-color: rgba(0, 0, 0, 0.1);

    --dark-background: #2c3e50;
    --dark-text: #ecf0f1;
    --dark-container: #34495e;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background-color 0.3s ease;
    background-image: linear-gradient(to top, rgba(255, 255, 255, 0.2), rgba(255, 255, 255, 0));
}

body.dark-mode {
    --background-color: var(--dark-background);
    --text-color: var(--dark-text);
    --shadow-color: rgba(255, 255, 255, 0.1);
}

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

body.dark-mode #generate {
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
}

.theme-switcher-container {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

#theme-toggle {
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#theme-toggle:hover {
    background-color: #357abd;
}

.container {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px var(--shadow-color);
    text-align: center;
    transition: transform 0.3s ease, background-color 0.3s ease;
}

.container:hover {
    transform: translateY(-5px);
}

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

#generate {
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 1rem 2rem;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.4);
}

#generate:hover {
    background-color: #357abd;
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.6);
}

.numbers-container {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.number {
    width: 50px;
    height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--white);
    border-radius: 50%;
    box-shadow: 0 2px 5px var(--shadow-color);
    transition: transform 0.3s, box-shadow 0.3s;
}

.number:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 10px var(--shadow-color);
}