CSS Variables City Skyline - Step 42

Cuéntanos qué está pasando:
I can’t get to find the error in my code. " Hint

You should add the bb1-window class to the .bb1a element. "

Tu código hasta el momento

<div class="bb1">
        <div class="bb1a" class="bb1-window"></div>
      <div class="bb1b" class="bb1-window"></div>
      <div class="bb1c" class="bb1-window"></div>
      <div class="bb1d"></div>

Please post your code and a link to the challenge. Thanks

I’ve edited your code for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.

You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.

See this post to find the backtick on your keyboard.
Note: Backticks (`) are not single quotes (').