CSS: Image inside Tooltip

• Related links
  • https://www.geeksforgeeks.org/how-to-make-a-tooltip-with-an-image/
  • https://stackoverflow.com/questions/43345898/style-css-not-applying-on-wordpress-theme
  • related keyword: wordpress image tooltip
    https://stackoverflow.com/questions/59781295/tooltip-in-wordpress
  • related keyword: image inside tooltip wordpress
    https://wordpress.com/ja/plugins/browse/image-tooltip
    • Prospective plugin: Tooltipster
  • related keyword: theme cube blog "css" support
    https://wordpress.org/support/theme/cubic/page/6/