Yes first remove this code background-color: transparent;
from this line (around line 1181 by default) –
.featured-section .site-header {
background-color: transparent;
border: none;
}
Next, you may want to remove the padding-top
that adds the extra space on top of the header (on the homepage template) –
.front-page .site-header {
border-bottom: 1px solid #ddd;
padding-top: 30px;
}
So once you remove the transparent background, and then the padding-top, it should show up as it does on all the other pages.
Let me know if that helps.