I want to make a horizontal section, like Quora.com

Here is what I come up with
<div class="out-wrapper">
  <div class="inner-wrapper">
    <% 6.times do %>
      <a class="nav-link pull-left" href="#">Nav 1</a>
    <% end  %>
  </div>
</div>
.out-wrapper{
  overflow-x: scroll;
  .inner-wrapper{
    /* width: 600px; */
    .nav-link{
      padding: 10px;
    }
  }
}
Demo: http://codepen.io/anon/pen/XJZyog
I can only create a horizontal scroll if I set the width to a fixed value. 
How can I do this without specify a fixed value? Like width: overall-width-of-children
So the width would automatically be the sum width of its all elements