const left = document.querySelector(".left"); const right = document.querySelector(".right"); const container = document.querySelector(".container"); left.addEventListener("mouseenter", () => container.classList.add("hover-left") ); left.addEventListener("mouseleave", () => container.classList.remove("hover-left") ); right.addEventListener("mouseenter", () => container.classList.add("hover-right") ); right.addEventListener("mouseleave", () => container.classList.remove("hover-right") );