(function(){
  'use strict';
  const sidebar=document.querySelector('.side');
  const menu=document.querySelector('.hamburger');
  if(menu&&sidebar){
    const close=()=>{sidebar.classList.remove('open');menu.setAttribute('aria-expanded','false')};
    menu.addEventListener('click',()=>{const open=sidebar.classList.toggle('open');menu.setAttribute('aria-expanded',String(open))});
    sidebar.querySelectorAll('a').forEach(a=>a.addEventListener('click',close));
    document.addEventListener('keydown',e=>{if(e.key==='Escape')close()});
  }
  const links=[...document.querySelectorAll('.nav-item[href^="#"]')].filter(a=>a.hash);
  const sections=links.map(a=>document.getElementById(a.hash.slice(1))).filter(Boolean);
  if('IntersectionObserver' in window&&sections.length){
    const observer=new IntersectionObserver(entries=>{
      const shown=entries.filter(x=>x.isIntersecting).sort((a,b)=>a.boundingClientRect.top-b.boundingClientRect.top);
      if(shown.length){const id=shown[0].target.id;links.forEach(a=>a.classList.toggle('active',a.hash==='#'+id))}
    },{rootMargin:'-15% 0px -67% 0px',threshold:0});
    sections.forEach(s=>observer.observe(s));
  }
  document.querySelectorAll('[data-print]').forEach(b=>b.addEventListener('click',()=>window.print()));
})();