Create a curve shape using css?
<p>i really need your help..</p>

<p>did anyone know how to make a shape like this using css?</p>

<p><a href="https://i.stack.imgur.com/WAOk0.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WAOk0.jpg" alt="enter image description here"></a></p>

<p>i tried to make it, but now i stuck..</p>

<p><a href="http://codepen.io/nassermaronie/pen/NxwMjY" rel="nofollow noreferrer">here's my code pen</a></p>

<p>Here's the css style and HTML</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-css lang-css prettyprint-override"><code>.a {
  width: 20%;
  height: 500px;
  background-color: red;
  display: inline-block;
  margin: 0;
}
.b {
  display: inline-block;
  position: absolute;
  width: 20%;
  height: 500px;
  background-color: black;
  margin: 0;
  border-radius: 50% 0 0 50%;
  left: 20%;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="container"&gt;
  &lt;div class="a"&gt;
    ...
  &lt;/div&gt;
  &lt;div class="b"&gt;
    ...
  &lt;/div&gt;
&lt;/div&gt;</code></pre>
</div>
</div>
</p>