regex tool

• https://regexr.com/

styleguides

• https://standardjs.com/rules.html
• https://github.com/airbnb/javascript

industry news

• https://news.ycombinator.com/
• https://hackernoon.com/

css

• https://css-tricks.com/centering-css-complete-guide/

DOM manipulation - event bubbling

• https://www.kirupa.com/html5/handling_events_for_many_elements.htm
• https://www.sitepoint.com/event-bubbling-javascript/