function animateElement(element, initialPositionX, initialPositionY, finalPositionX, finalPositionY, initialOpacity, finalOpacity  = (t) => t * t) {
    const startTime = performance.now();
    const animationFrame = requestAnimationFrame(function animate(timestamp) {
      const newPositionX = initialPositionX + (finalPositionX - initialPositionX) * easedProgress;
      const newOpacity = initialOpacity + (finalOpacity - initialOpacity) * easedProgress;
      element.style.transform = `translateX(${newPositionX}px) translateY(${newPositionY}px)`;
      element.style.opacity = newOpacity;
      if (progress < 1) {
        requestAnimationFrame(animate);
      }
    });
  }
  
  // Example usage: animate a button to slide down and fade in from off-screen
  const button = document.getElementById("myButton");
  animateElement(button, -100, 0, 0, 100, 0, 1, 1000);