title: How to draw realistic smooth slit shadow with Pure CSS3?
body: <p>How can I make a shadow effect like the one below with pure CSS? </p>
  
  <p><img src="https://i.stack.imgur.com/XY5m2.png" alt="Shadow Effect"></p>
  
  <p>I am new to CSS.
  The following is what I have tried so far, but I am unable to come close to what I want.  Please advise how I can make it look like the shadow in the image? Thanks!</p>
  
  <pre><code>box-shadow: 1px 1px 5px #999999 inset
  </code></pre>