Make empty div background colour fill entire div vertically - html

Question

I have a div inside a div and I want the inside div to either contain a background colour or background image. My code is:
<div class="row two">
<div class="cols n15">
<h2 class="latestVideo">Latest Video</h2>
<iframe width="100%" height="370" src="//www.youtube.com/embed/a-XQL60NVmQ" frameborder="0" allowfullscreen></iframe>
</div>
<div class="cols n9 clearfix">
<h2>Other Videos</h2>
<div class="otherVids">
<p>"test"<p>
<!-- <img src="images/otherVideos.jpg" alt=""> -->
<div class="video1">
</div>
<div class="vidoe2">
</div>
<div class="video3">
</div>
</div>
<div style="clear:both"></div>
Right now this makes it look like this:
What I want is for the red box to extend all way down and match the height of the div on the left side. I realize that this would work if I have the div(otherVids) a height and width, but if I do this the website won't be responsive anymore.
So if there anyway to make the div background fill up the empty space while still remaining responsive?
Here is the CSS code I have:
.otherVids{
background-image: url('images/otherVideos.jpg');
background-color: red;
width: 100%;
height: 100%;
}

Answer 1

Try setting the height of otherVids to be equal to the iframe.
Add height:370px; to the css of .otherVids

Answer 2

You can try two method,the first thing is:
.otherVids{
min-height:370px;
}
or:
.otherVids{
height:370px;
overflow-y:scroll;
}
if your video list is to many,you need to design the content responsive.
finally,I think you don't need use width:100%,because div is block element.