Issue with rails hotwire trix textarea resize

Hello, im trying to create a textarea resize grippie more or less like the SO for a trix textarea with rais stimulus so i set this controller below

the issue is when i pull down the textarea the textarea blow all the page, and i have any idea why, someone that know hotwire better can point my mistake please?

// app/javascript/controllers/textarea_resizer_controller.js

import { Controller } from "@hotwired/stimulus";

export default class extends Controller {
static targets = ["textarea", "grippie"];

connect() {
this.textareaTarget.classList.add("processed");
this.setupGrippie();
}

setupGrippie() {
this.grippieTarget.addEventListener("mousedown", this.startDrag.bind(this));
}

startDrag(event) {
event.preventDefault();
this.lastMousePos = this.mousePosition(event).y;
this.staticOffset = this.textareaTarget.offsetHeight - this.lastMousePos;
this.textareaTarget.style.opacity = 0.25;

document.addEventListener("mousemove", this.performDrag.bind(this));
document.addEventListener("mouseup", this.endDrag.bind(this));
}

performDrag(event) {
const currentMousePos = this.mousePosition(event).y;
let newHeight = this.staticOffset + currentMousePos;

if (this.lastMousePos >= currentMousePos) {
newHeight -= 5;
}
this.lastMousePos = currentMousePos;
newHeight = Math.max(32, newHeight);

this.textareaTarget.style.height = `${newHeight}px`;

if (newHeight < 32) {
this.endDrag(event);
}
}

endDrag() {
document.removeEventListener("mousemove", this.performDrag.bind(this));
document.removeEventListener("mouseup", this.endDrag.bind(this));

this.textareaTarget.style.opacity = 1;
this.lastMousePos = 0;
this.staticOffset = null;
}

mousePosition(event) {
return {
x: event.clientX + document.documentElement.scrollLeft,
y: event.clientY + document.documentElement.scrollTop,
};
}
}

Start with the supplied markup and app/javascript/controllers/textarea_resizer_controller.js, then reproduce the drag behavior with the Trix rich text area. Determine why dragging causes the textarea to expand across the page; done means the resize grip changes the editor height without uncontrolled expansion.

Written by the indexing model from the issue text.