Why does the header, managed with flexbox, render differently when I put content into an iframe? The iframe content appears different from the original. Check it out at this link.
header {
display: flex;
justify-content: space-between;
margin: 25px 10px 25px 10px;
border-bottom: 25px solid #f2f2f2;
padding-bottom: 25px;
}
Responsive emulation in Chrome looks fine: https://i.sstatic.net/qcSi1.png
However, the URL inside the iframe doesn't render correctly: