I need scrollbar on inner element, not browser window (viewport) - html

Question

In the code below, how do I make the article container auto grow to consume the remaining vertical space below it, but the scroll bar to remain only for that element.
In other words, I want only the inside of article to scroll and not the entire browser window.
Is there a pure css solution? Or do I need javascript to detect the size of the browser window and adjust the height property of article dynamically?
html, body {
//height: 100%;
}
#outer_container {
display: flex;
flex-direction: row;
}
#outer2 {
flex: 1 0 auto;
}
#outer2 {
flex: 1 0 auto;
}
#container {
display: flex;
flex-direction: column;
height: 100%;
width: 50%;
background-color: red;
}
#container header {
background-color: gray;
}
#container article {
flex: 1 1 auto;
overflow-y: auto;
height: 0px;
}
#container footer {
background-color: gray;
}
<div id="outer_container">
<div id="outer1">
<h2>Outer 1</h2>
</div>
<section id="container">
<header id="header">This is a header</header>
<article id="content">
This is the content that
<br />With a lot of lines.
<br />With a lot of lines.
<br />This is the content that
<br />With a lot of lines.
<br />
<br />This is the content that
<br />With a lot of lines.
<br />
<br />This is the content that
<br />With a lot of lines.
<br />
</article>
<footer id="footer">This is a footer</footer>
</section>
<div id="outer2">
<h2>Outer 2</h2>
</div>
</div>
http://jsfiddle.net/ch7n6/907/
It was originally based on the answer to this question:
Flexbox and vertical scroll in a full-height app using NEWER flexbox api

Answer 1

You can try setting position:fixed to your outer container (http://jsfiddle.net/ch7n6/909/):
#outer_container{
display:flex;
flex-direction:row;
top:0;
bottom:0;
position:fixed;
}
If it doesn't work for your design, you can change the container dimensions using window.onresize event.

Answer 2

In your code you commented out:
html, body {
//height: 100%;
}
But I think you were on the right track.
By uncommenting that rule, and adding height: 100% to .outer_container, your layout may be complete.
Try this:
html, body {
height: 100%; /* uncommented */
margin: 0; /* removes default margin */
}
#outer_container {
height: 100%; /* new; see details below */
display: flex;
flex-direction: row;
}
#outer2 {
flex: 1 0 auto;
background-color: lightblue; /* just for demo */
}
#outer1 { /* correction to duplicate ID */
flex: 1 0 auto;
background-color: lightgreen; /* just for demo */
}
#container {
display: flex;
flex-direction: column;
height: 100%;
width: 50%;
background-color: red;
}
#container header {
background-color: gray;
}
#container article {
flex: 1 1 auto;
overflow-y: auto;
height: 0px;
}
#container footer {
background-color: gray;
}
<div id="outer_container">
<div id="outer1">
<h2>Outer 1</h2>
</div>
<section id="container">
<header id="header">This is a header</header>
<article id="content">
This is the content that
<br />With a lot of lines.
<br />With a lot of lines.
<br />This is the content that
<br />With a lot of lines.
<br />
<br />This is the content that
<br />With a lot of lines.
<br />
<br />This is the content that
<br />With a lot of lines.
<br />
</article>
<footer id="footer">This is a footer</footer>
</section>
<div id="outer2">
<h2>Outer 2</h2>
</div>
</div>
jsFiddle
To understand how this solution works, and what may have held you up, take a look at these posts:
Working with the CSS height property and percentage values
Chrome / Safari not filling 100% height of flex parent