num/docs/presentation/runtime.js

;(function(){
'use strict';

const deck = document.querySelector('.deck');
if (!deck) return;

const slides = deck.querySelectorAll('.slide');
const total = slides.length;

// Insert slide numbers
slides.forEach((sl, i) => {
  const footer = sl.querySelector('.slide-number');
  if (footer) {
    footer.dataset.current = i + 1;
    if (total > 1) footer.dataset.total = total;
  }
  sl.dataset.index = i;
});

let current = 0;
let isAnimating = false;

function goTo(idx){
  if(isAnimating) return;
  idx = Math.max(0, Math.min(idx, total - 1));
  if(idx === current) return;
  isAnimating = true;

  const dir = idx > current ? 1 : -1;
  slides.forEach((sl, i)=>{
    sl.classList.remove('is-active', 'is-prev');
  });
  slides[current].classList.add('is-prev');
  slides[idx].classList.add('is-active');
  current = idx;

  setTimeout(()=>{ isAnimating = false; }, 550);
}

function next(){ goTo(current + 1); }
function prev(){ goTo(current - 1); }

// Keyboard nav
document.addEventListener('keydown', e=>{
  if(e.key === 'ArrowRight' || e.key === 'ArrowDown' || e.key === ' ') { e.preventDefault(); next(); }
  if(e.key === 'ArrowLeft' || e.key === 'ArrowUp') { e.preventDefault(); prev(); }
  if(e.key === 'Home') goTo(0);
  if(e.key === 'End') goTo(total - 1);
});

// Click/tap nav
deck.addEventListener('click', e=>{
  if(e.target.closest('.slide-inner')) return;
  if(e.target.closest('.deck-footer')) return;
  const w = deck.clientWidth;
  if(e.clientX > w * 0.6) next();
  else if(e.clientX < w * 0.4) prev();
});

// Touch support
let tx = 0;
deck.addEventListener('touchstart', e=>{ tx = e.changedTouches[0].clientX; }, {passive:true});
deck.addEventListener('touchend', e=>{
  const dx = e.changedTouches[0].clientX - tx;
  if(Math.abs(dx) < 60) return;
  dx > 0 ? prev() : next();
}, {passive:true});

// Init first slide
slides[0] && slides[0].classList.add('is-active');

})();