JavaScript를 사용하여 다크/라이트 모드를 전환하는 방법

사용 라이브러리

<div class="container">
        <div class="header d-flex justify-content-between">
            <h1 class="title mt-2">Catty's Blog</h1>
            <span class="mt-4 fs-3 dark toggle"><i class="fas fa-moon d-none" id="dark" title="Switch to Dark Mode"></i></span>          
            <span class="mt-4 fs-3 light toggle" id="light"><i class="fas fa-sun" title="Switch to Light Mode"></i></span>          
        </div>
        <center>
            <div class="main">
                <div class="">
                    <img src="assets/cat-2.webp" class="catty mt-2 rounded-circle" alt="I am Catty">
                    <div class="card-body">
                        <h1 class="card-title">
                            Hello there, I am <a href="http://github.com/snowbit-coderboi" target="_blank" class="catty-name text-decoration-none" id="cattyName">Catty</a>
                        </h1>
                        <p class="info">
                            Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
                        </p>
                    </div>
                </div>
            </div>
        </center>
    </div>

@import url('https://fonts.googleapis.com/css2?family=Amatic+SC:wght@700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Sacramento&display=swap');
body{
    background-color: #212224;
    color: #fff;
    transition: 0.5s;
    -webkit-transition: 0.5s;
    -moz-transition: 0.5s;
    -ms-transition: 0.5s;
    -o-transition: 0.5s;
}

.title{
    font-family: 'Amatic SC', cursive;
    font-size: 60px;
    user-select: none;
}

.toggle{
    cursor: pointer;
    transition: 0.5s;
    -webkit-transition: 0.70s;
    -moz-transition: 0.70s;
    -ms-transition: 0.70s;
    -o-transition: 0.70s;
}
#light:hover{
    color: yellow;
}

.catty-name{
    color: #fff;
    transition: 0.3s;
    -webkit-transition: 0.3s;
    -moz-transition: 0.3s;
    -ms-transition: 0.3s;
    -o-transition: 0.3s;
}
.catty-name:hover{
    color: #fff;
    transition: 0.7s;
    -webkit-transition: 0.7s;
    -moz-transition: 0.7s;
    -ms-transition: 0.7s;
    -o-transition: 0.7s;
    font-size: 70px;
}
.main{
    margin-bottom: 15px;
    margin-top: 20px;
}
.card-title{
    font-family: 'Sacramento', cursive;
    font-size: 60px;
}
.card-list{
    /* font-family: 'Sacramento', cursive; */
    font-size: 30px;
    list-style: none;
}
.card-list li:before { content: '😸'; margin-left: -10px; margin-right: 10px; } 

.catty{
    max-height: 200px;
    object-fit: contain;
    /* transform: rotate(20deg); */
    transition: 0.70s;
    -webkit-transition: 0.70s;
    -moz-transition: 0.70s;
    -ms-transition: 0.70s;
    -o-transition: 0.70s;
}
.catty:hover{
    transition: 0.70s;
  -webkit-transition: 0.70s;
  -moz-transition: 0.70s;
  -ms-transition: 0.70s;
  -o-transition: 0.70s;
  -webkit-transform: rotate(350deg);
  -moz-transform: rotate(350deg);
  -o-transform: rotate(350deg);
  -ms-transform: rotate(350deg);
  transform: rotate(360deg);
}
.catty{
    max-height: 200px;
    object-fit: contain;
    /* transform: rotate(20deg); */
    transition: 0.70s;
    -webkit-transition: 0.70s;
    -moz-transition: 0.70s;
    -ms-transition: 0.70s;
    -o-transition: 0.70s;
}
.info{
    text-align: justify;
    line-height: 2em;
    max-width: 900px;
    font-size: 18px;
}

const dark = document.getElementById('dark')
const light = document.getElementById('light')
const catty = document.getElementById('cattyName')

function toggleDark(){
    dark.classList.add('d-none')
    light.classList.remove('d-none')
    document.body.style.backgroundColor = "#212224"
    document.body.style.color = "#fff"
    catty.style.color = "#fff"
}

dark.addEventListener('click', toggleDark)

function toggleLight(){
    light.classList.add('d-none')
    dark.classList.remove('d-none')
    document.body.style.backgroundColor = "#fff"
    document.body.style.color = "#000"
    catty.style.color = "#000"
}
light.addEventListener('click', toggleLight)