title: Inverted Scooped corners using CSS
body: <p>I have CSS code</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>#box {
    width: 200px;
    height: 50px;
    background-color: blue;
    border-top-left-radius: 9999px;
    border-bottom-left-radius: 9999px;
    position: relative;
    margin: 30px;
    text-align: center;
    color: white;
    padding-top: 10px;
  }
  
  #box::before,
  #box::after {
    content: "";
    width: 0;
    height: 0;
    right: 0;
    position: absolute;
  }
  
  #box::before {
    border-right: 10px solid blue;
    border-top: 10px solid blue;
    border-left: 10px solid transparent;
    border-bottom: 10px solid transparent;
    bottom: -20px;
  }
  
  #box::after {
    border-right: 10px solid blue;
    border-top: 10px solid transparent;
    border-left: 10px solid transparent;
    border-bottom: 10px solid blue;
    position: absolute;
    top: -20px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="box"&gt;#box&lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>which gives some shape like</p>
  
  <p><a href="https://i.stack.imgur.com/SjW16.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SjW16.png" alt="box with inverted scooped corners"></a></p>
  
  <p>shape I need is
  <a href="https://i.stack.imgur.com/TlH2M.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TlH2M.png" alt="enter image description here"></a></p>
  
  <p>I need curved line instead of hypotenuse in triangles at top-right (<code>#box::before</code>) and bottom-right (<code>#box::after</code>) as in image.</p>
  
  <p>Is there any way to achieve using pure CSS ?</p>
  
  <p>codesandbox <a href="https://codesandbox.io/s/youthful-sun-33k72" rel="nofollow noreferrer">demo</a></p>
  
  <p>Thanks</p>