completely hide header on single page

Hi all,

Im trying to hide my header for my landing page, but its still showing the white bar. here is the code im using thus far

#collection-5f77546d44a1ed498bae102e
{.Header-nav-item{ display: none; } }
#collection-5f77546d44a1ed498bae102e 
{footer {display: none} 
 header {display: none}
 }

Can you share link to page in screenshot? We can check easier.