funcion.js

let current = 0;
const slides = document.querySelectorAll('.mySlides');
const total = slides.length;

function showSlide(index) {
 slides.forEach((slide, i) => {
 slide.classList.toggle('active', i === index);
 });
}

document.getElementById('next').onclick = function () {
 current = (current + 1) % total;
 showSlide(current);
};

document.getElementById('prev').onclick = function () {
 current = (current - 1 + total) % total;
 showSlide(current);
};