Yes, exactly (added as it is, to a page with Classic Editor). In my case I made a 16x10 box, infact I added to the theme the CSS part as following:
.hype-box-16x10 {
position: relative;
width: 100%;
height: 0;
padding-top: 62.50%;
margin-bottom: 20px;
}
.hype-iframe {
position: absolute;
top: 0;
width: 100%;
height: 100%;
border: none;
overflow: hidden;
}
Where 62.50% refers to 16/10 ratio.
The sole part I didn't use is the following:
<div class="hype-box-16x10">
<iframe class="hype-iframe" src="/files/templates/physics" allowfullscreen="allowfullscreen">
</iframe>
</div>