readme.md

• this's value is not the same in a regular function as in an arrow function:
  • inside a regular function: it refers to whatever this value the function is called upon

    function toggleOpen() {
      this.classList.toggle('open'); // Here `this` refers to `panel`
      setTimeout(() => this.classList.toggle('open-active'), 900);
    };
    
    panels.forEach(panel => panel.addEventListener('mouseover', toggleOpen));

  • inside an arrow function: it refers to the global this