dc2d", "#69d451", "#54c939", "#34b916", "#28b309", "#1e9c02",
        ];

        circles.forEach(function (circle, index) {
            circle.x = 0;
            circle.y = 0;
            circle.style.backgroundColor = colors[index % colors.length];
        });

        // update the coordinates when the mouse moves:
        window.addEventListener("mousemove", function (e) {
            coords.x = e.clientX;
            coords.y = e.clientY;
        });

        // animation function to move the circles:
