function enhance_textareas() {
	const textareas = document.body.querySelectorAll("textarea:not([data-enhanced])");
	for (const textarea of textareas) {
		const max_length_attr = textarea.getAttribute("maxlength");
		if (/^\d+$/.test(max_length_attr)) {
			const max_length = parseInt(max_length_attr, 10);

			function on_updated() {
				const counters = this.parentElement.querySelectorAll(
					`[data-limit-counter-for="${this.name}"]`,
				);
				for (const counter of counters) {
					counter.innerHTML = `${this.value.length} / ${max_length}`;
				}
			}

			textarea.addEventListener("keyup", on_updated);
			textarea.addEventListener("paste", on_updated);
			textarea.addEventListener("blur", on_updated);
			on_updated.call(textarea);
		}

		textarea.dataset.enhanced = true;
	}
}

const textarea_enhancement_observer = new MutationObserver(enhance_textareas);
textarea_enhancement_observer.observe(document, {
	childList: true,
	subtree: true,
});