.two-column{display:flex;gap:2rem;width:100%}@media(max-width:900px){.two-column{display:block}}.two-column .half-column{flex-basis:50%;box-sizing:border-box;max-width:50%}@media(max-width:900px){.two-column .half-column{max-width:unset}}#demo-frame{width:100%;height:400px;border:2px solid #000}