Untitled

dabblet.css

.lft-column {
	width: 70%;
	
	background: indianred;
	}

.rt-column {
	width: 250px;
	overflow: hidden;/* This does the magic */
	float: right;
	background: dodgerblue;
	}
	
	/* VISUAL */	
	html, body, .lft-column, .rt-column {
	height: 100%;
	}
	
	
	
	
	
	
	
	
	
	

dabblet.html

<div class="lft-column"></div>
<div class="rt-column"></div>

settings.json

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