Untitled

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Basic</title>
</head>
<body>
  <div id="milestone">
      <div id="milestonecontent">
          <div id="event">
           </div>
      </div>
      <div class="actions">
      </div>
  </div>
</body>
</html>

#body{
  background-color: #e9eaed;
}

#milestone{
  width: 512px;
  height: 137px;
  background-color: blue;

}

#milestonecontent{
  width: 512px;
  height: 104px;
  background-color: green;
}
#event{
  position: relative;
  margin: 10px auto;
  width: 512px;
  height: 58px;
  background-color: red;

}
.actions{
  border-top: 1px solid #e9eaed;
  position: relative;
  width: 512px;
  height: 33px;
  background-color: grey;
}

#milestonecontent{
  width: 512px;
  height: 104px;
  background-color: green;
  overflow: auto;
}

#event {
    display: inline-block;
    margin-top: 23px;
}

#milestonecontent{
  height: 104px;
  padding-top:20px;
  background-color: green;
}

#event{
  margin: 0 auto;
  width: 300px;
  height: 58px;
  background-color: red;
}