Responsive columns within an article

Hi.

I'm looking to have two columns within an article, the first column being slightly wider than the second (say 60%: 40%)

The following code will work, but it creates two equally sized columns:



<div class="col-2"><div>First column of your content...</div></div>

<div class="col-2"><div>Second column of your content...</div></div>

<div class="clear"></div>

I was trying to get bootstrap to work. I.e. using the following example from their website:



<div class="container-fluid">

<div class="row">

<div class="col-sm-6">.col-sm-6</div>

<div class="col-sm-3">.col-sm-3</div>

</div>

</div>

... but that doesn't work within an article, using a Joomla51 template.

Could you please advise what's the best way to achieve this?

Many thanks
Marc