function updateLineNumbers() {
  const lineNumbersDiv = document.getElementById("line-numbers");
  if (!editor || !lineNumbersDiv) return;
  const lines = editor.value.split(/\r\n|\r|\n/).length;
  let content = '';
  for (let i = 1; i <= lines; i++) {
    content += i + '<br>';
  }
  lineNumbersDiv.innerHTML = content;
}

if (editor) {
    editor.addEventListener('scroll', () => {
      const lineNumbersDiv = document.getElementById("line-numbers");
      if (lineNumbersDiv) lineNumbersDiv.scrollTop = editor.scrollTop;
    });
}