text: Q:
  
  Why is there a back slash in tailwind css class names?
  
  I am trying to learn and use a new utility framework which is getting very popular these days. TailwindCSS
  When I compiled my css using the instructions in the docs, I saw a lot of css class names have colon : in them and it is preceded by a back slash \
  Why is that? Is that to make CSS understand that there is a : there and not to escape it?
  
  A:
  
  Tailwind uses class names with colons as part of its support for Responsive Design. In particular, a class name such as 
  tablet:bold
  
  Means that the properties defined in the class bold should be applied but only if the media matches the media query defined as tablet.
  A colon is a perfectly valid character in an HTML5 class name. It is, however, a reserved character in a CSS selector. So, if you want to select elements with a class whose name contains a colon, you need to escape the colon.
  So, if you have HTML like this:
  <p class="one:two"></p>
  
  And you want to select that element, the corresponding query selector would be something like:
  .one\:two
  
  