<prompt> Kuandika HTML code ambayo inaonyesha mduara pulsing katikati ya ukurasa. By pulsing, I mean kupanua na kuondokana mara kwa mara.  <response>: Here is an example HTML code that displays a pulsing circle in the middle of the page using CSS animation:In this code snippet, we have created a div element with a class of circle that represents the pulsing circle. We have used CSS to set its height, width, background color, and border-radius to create a circle.Then, we have defined a CSS keyframe animation called pulse that scales the circle up to 1.2 times its original size and then back to its original size. We have set the animation duration to 1.5 seconds and set it to run indefinitely using the infinite keyword.Finally, we have created another div element with a class of center and used CSS flexbox to center the circle div element horizontally and vertically in the middle of the page. 