Remove top gradient in Google Photos

google-photos.user.css

/* ==UserStyle==
@name           Remove top gradient in Google Photos - 09/07/2019, 22:08:26
@namespace      github.com/niieani
@version        1.0.0
@description    Removes the annoying top gradient in the Google Photos views: full screen photo, album
@author         Bazyli Brzóska
==/UserStyle== */
@-moz-document domain("photos.google.com") {
  .KYCEmd {
    background-image: none;
  }
  .DwJIde .NRbSyd {
    background-image: none;
  }
}