:root {
    --background-color-light: #f0f2f5;
    --container-bg-light: #fff;
    --text-color-light: #333;
    --button-bg-light: #008CBA;
    --button-hover-bg-light: #005f7a;

    --background-color-dark: #121212;
    --container-bg-dark: #1e1e1e;
    --text-color-dark: #f0f2f5;
    --button-bg-dark: #005f7a;
    --button-hover-bg-dark: #008CBA;
}

body {
    font-family: 'Arial', sans-serif;
    background-color: var(--background-color-light);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    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-bg-light);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    transition: background-color 0.3s;
}

body.dark-mode .container {
    background-color: var(--container-bg-dark);
    box-shadow: 0 10px 20px rgba(255, 255, 255, 0.1);
}

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

body.dark-mode h1 {
    color: var(--text-color-dark);
}

.theme-switch-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.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: .4s;
}

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

input:checked + .slider {
    background-color: #2196F3;
}

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

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

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

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

.number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #4CAF50;
    color: white;
    font-size: 24px;
    font-weight: bold;
    display: flex;
    justify-content: center;
    align-items: center;
    animation: reveal 0.5s ease-in-out;
}

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

#generate {
    background-color: var(--button-bg-light);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 18px;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s;
}

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

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

body.dark-mode #generate:hover {
    background-color: var(--button-hover-bg-dark);
}

@media (max-width: 600px) {
    .container {
        padding: 20px;
    }
    .number {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }
    #generate {
        padding: 12px 25px;
        font-size: 16px;
    }
}