Fixed width sidebar isn't the right size in Tailwind CSS-CodePudding

I have this simple HTML and I am using tailwindcss.

<!DOCTYPE html>
<html  lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Static Template</title>
    <script src="https://cdn.tailwindcss.com"></script>
  </head>
  <body >
    <div id="app" >
      <div >
        <h1 >
          Sidebar
        </h1>
      </div>
      <div >
        <h1 >
          Main
        </h1>
      </div>
    </div>
  </body>
</html>

For some reason, my sidebar's width is not 312px like I want it to be.

What am I missing? Here is a CodeSandbox too.

CodePudding user response：

Just add flex-none to prevent div from growing and shrinking. Like that.

 <div >
     <h1 >
          Sidebar
    </h1>
 </div>