html 문서가 로딩되면 실행되도록하는 jQuery

<!-- HTML -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<div class="test">Hello World</div>
<h1>안녕하세요?</h1>
<div class="night">지금은 밤입니다.</div>

// jQuery
$(document).ready(function(){
  $('.test').css('color', 'red');
})

$(document).ready(function() {
  $( "h1" ).css( "color", "green" );
});

$(function(){
  $('.night').css('font-size', '2rem');
});

See the Pen RwKLLov by hyeryeonkim (@khr777) on CodePen.