Arcueid Firefox theme. A big thanks to the artist shirotsumekusa, according to the info on danbooru. He or she definitely has a big heart, besides the obviously awesome skills. All credits go to Crazy Clover Club (CCC), who are also awesome. For anyone wondering what was all that about, you may check out the doujin at danbooru.donmai.us/pools/620. I do not own this awesome picture, just adjusted it to create a firefox theme. For best appearance, switch your firefox appearance to classic one, with 2 or 3 toolbars one under another, and force the tabstrip to be under the toolbars.