Fix CSS for admin page and put some CSS from inline to style files

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
2 jobs for fix-css-admin in 1 minute and 5 seconds
Status Job ID Name Coverage
  Test
passed #95147
test_php7.0

00:01:04

passed #95148
test_php7.1

00:01:05