Rsa97

this.resultlist = [...document.querySelectorAll('.list-group > a')]

document.addEventListener('DOMContentLoaded', _ => {
  const bgColor = localStorage.getItem('bgColor')
  if (bgColor !== null) {
    document.querySelectorAll('.box').forEach(i => {
      i.style.backgroundColor = bgColor
    })
  }
})

$('.link').click(function() {
  let url = $(this).data('url');
  url = `side/${url}.html`;
  ...
}

$('.link').click(function() {
  $.ajax({
    url: $(this).data('url'),
    success: function(html) {
      $('#text_0').html(html);
    }
  });
});