Online advertising

 The world still uses the predefined formats that prevailed in the early days of the Internet, when pages were mostly read on a desktop/laptop. Leaderboard, skyscraper, wide skyscraper, etc. But most users use mobile phones today. Those who want to serve static ads in image format have a problem if they want to display the same image on both desktop and mobile: none of the formats fit except square ones. Instead, add-on platforms have become more specialized, using codes to determine the user's screen size and serve the ad accordingly. However, what do you do when the user resizes?

very large