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

[data-theme="dark"] {
    --primary-color: #79b8ff;
    --background-color: #1a1a1a;
    --text-color: #e1e1e1;
    --white: #2a2a2a;
    --shadow-color: rgba(255, 255, 255, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    text-align: center;
    background-color: var(--white);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 10px 20px var(--shadow-color);
    max-width: 90%;
    position: relative;
}

.theme-switch-wrapper {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.theme-switch {
    display: inline-block;
    height: 34px;
    position: relative;
    width: 60px;
}

.theme-switch input {
    display: none;
}

.slider {
    background-color: #ccc;
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: 0.4s;
}

.slider:before {
    background-color: #fff;
    bottom: 4px;
    content: "";
    height: 26px;
    left: 4px;
    position: absolute;
    transition: 0.4s;
    width: 26px;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}

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: 1.2rem;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    box-shadow: 0 4px 10px rgba(74, 144, 226, 0.4);
}

#generate:hover {
    background-color: #357abd;
    transform: translateY(-2px);
}

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

.number {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50px;
    height: 50px;
    background-color: #e1e8ed;
    color: var(--text-color);
    border-radius: 50%;
    font-size: 1.5rem;
    font-weight: bold;
    box-shadow: 0 2px 5px var(--shadow-color);
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@media (max-width: 600px) {
    .container {
        padding: 1.5rem;
    }

    h1 {
        font-size: 1.8rem;
    }

    #generate {
        font-size: 1rem;
        padding: 0.8rem 1.5rem;
    }

    .number {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }
}