Hwo to add opacity Hover effect to header


this is my blog www.richelacabal.blogspot.com can someone help me add CSS to my header :frowning: i tried the tutorials online but they dont have the same CSS with my logo, my log o just has "#logo } as CSS idk if i should use a: hover or what please help me :frowning: :frowning:

i wanted that if you hover on my logo, it would turn a little bit grey :slight_smile: