@ayo In a normal situation, you can easily do that by using your browser's developer tools. But, of course, if you use JS (or Perl) to generate HTML dynamically, it may be more complicated. My advice would be that, if you're really forced to do it that way for some sick reason, you use HTML <template> elements and identifiable class names or id attributes, so you can have some traceability. Also, never use stuff like Bootstrap.