/* ===== Global JS (lightweight slider) ===== */
(function(){
const slider = document.getElementById('treatmentsSlider');
if(!slider) return;
const viewport = slider.querySelector('.treat-viewport');
const track = slider.querySelector('.treat-track');
const prevBtn = slider.querySelector('.treat-nav.prev');
const nextBtn = slider.querySelector('.treat-nav.next');
function stepSize(){
const first = track.children[0];
const gap = parseFloat(getComputedStyle(track).gap) || 0;
return first.getBoundingClientRect().width + gap;
}
function updateButtons(){
// small tolerance for floating point
const maxScroll = track.scrollWidth - viewport.clientWidth - 2;
prevBtn.disabled = viewport.scrollLeft <= 2;
nextBtn.disabled = viewport.scrollLeft >= maxScroll;
}
function move(dir){
viewport.scrollBy({ left: dir * stepSize(), behavior: 'smooth' });
}
prevBtn.addEventListener('click', ()=>move(-1));
nextBtn.addEventListener('click', ()=>move(1));
viewport.addEventListener('scroll', updateButtons, { passive:true });
window.addEventListener('resize', updateButtons);
// init
updateButtons();
})();