Failed:Your #navbar element should always be at the top of the viewport.
CSS
header {
position: fixed;
width: 100%;
top: 0;
left: 0;
background-color: black;
}
This seems to have passed the condition, but I don’t know why it failed.
==
Solved by adding #navbar next to the header {}
header #navbar {
position: fixed;
width: 100%;
top: 0;
left: 0;
background-color: black;
}