title: How to specify the system’s default serif and sans-serif font-family?
body: <p>When I learned CSS over a decade ago, the standard (and only) way to use the "default fonts" (whatever that means) was:</p>
  
  <pre><code>font-family: serif;
  font-family: sans-serif;
  </code></pre>
  
  <p>Then, last year, Apple added a <a href="https://stackoverflow.com/questions/32660748/how-to-use-apples-new-san-francisco-font-on-a-webpage">custom syntax for their new system font</a>, and Blink did something similar if I remember correctly. </p>
  
  <p>Can someone who's more up-to-date with CSS summarize how my <code>font-family</code> property should look like when I just want the default sans-serif or serif font? (I specifically don't want webfonts.)</p>