iframe code from .net to weebly

[Dapple]

I have a snippet of code that is an online calculator which has been working within an iframe on our current site built on .net.  I am rebuilding in Weebly - how do I get this code to work on weebly - the only feature I see is <embed code> but it only takes the plain text and does not activate the code.  

THE ER SAVINGS CALCULATOR&nbsp;</span></strong></h2>

<p>&nbsp;</p>

<div class="total-cal">
<div>
<div class="cal-heading">Slide to Select Your&nbsp;Total Covered Lives</div>

<div aria-disabled="false" class="ui-slider ui-slider-horizontal ui-widget ui-widget-content ui-corner-all" id="BH-calc">&nbsp;</div>
</div>

<div class="row">
<div class="coll50 orng-bg border-right full-mob">
<div class="row">
<div class="coll50 text-black">
<div id="erEpisodeStart">&nbsp;</div>

<div class="to-bg">to</div>
</div>

<div class="coll50 text-black">
<div id="erEpisodeEnd">&nbsp;</div>
</div>
</div>

<div class="dark-orng">(Avoidable ER Episodes Per Your Total Covered Lives)*</div>
</div>

<div class="coll50 orng-bg full-mob">
<div class="row">
<div class="coll50 text-black">
<div id="employerSaveStart">&nbsp;</div>

<div class="to-bg">to</div>
</div>

<div class="coll50 text-black">
<div id="employerSaveEnd">&nbsp;</div>
</div>
</div>

<div class="dark-orng">(Possible Employer Savings Utilizing Hybrid Model)**</div>
</div>
</div>
</div>

<p><span style="color:#808080;"><span style="font-family:georgia,serif;"><em><span style="background-color: rgb(255, 255, 255);">*2013 Truven Health Analytics Study Avoidable ER Department Usage Analysis</span></em></span><br />
<span style="font-family: georgia, serif; font-style: italic; line-height: 1.2;">

[NorthGeorgiaWx]

You're going to have to include your CSS code if you want any of the CSS "class" settings to work.

[Dapple]

Great, thank you.  Before I go into my network to figure that out - is CSS something I can write in myself or do I need this completely re-written to include "class"