The first commented line is your dabblet’s title

dabblet.css

/**
 * The first commented line is your dabblet’s title
 */
.wrapper {
	height: 500px;
	background: #f3f3f3;
	width: 1200px;
	margin: 20px auto;
	display: flex;
	justify-content:space-between;
}

.wrapper-secondary {
	background: #dedede;
}

section {
	width: 732px;
	background: #bbb;
}

aside {
	background: #aeaeae;
	width: 408px;
}

.vertical-stack {
	display: flex;
	flex-direction: column;
}
.box {
	height: 50px;
	background: green;
	margin-bottom: 20px;
}

.box-full {
	background: yellow;
	flex-grow: 1;
}

dabblet.html

<article class="wrapper">
	<section class="vertical-stack">
		<div class="box">This is placholder for breadcrumbs, it's not fixed in this version</div>
		<div class="box-full">This is section which expands till the end of container even though it does not have enough content.</div>
	</section>
	<aside>Comments</aside>
</article>

dabblet.js

// alert('Hello world!');

settings.json

{"view":"split","fontsize":"100","seethrough":"","prefixfree":"1","page":"all"}