While you are right about the books of Stroustrup, here your inference is wrong, because Stroustrup cannot have anything to do with the CSS style sheets of the

While you are right about the books of Stroustrup, here your inference is wrong, because Stroustrup cannot have anything to do with the CSS style sheets of the ACM Web site, which, in conjunction with the browser settings, determine the font used for rendering the text. On my browser, all the code is properly indented, most likely because my browsers are configured correctly, i.e. with a monospace font set as the default for "monospace". Whoever does not see indentation, most likely has not set the right default font in their browser.