ctx.fill();
                    }

                    update() {
                        this.x += this.vx;
                        this.y += this.vy;

                        if (this.x < 0 || this.x > width) this.vx *= -1;
                        if (this.y < 0 || this.y > height) this.vy *= -1;
                    }
                }
                
                let particles = [];
                function init() {
                    width = canvas.offsetWidth;
                    he