Can not log in to Minecraft.net (Mojang) and Minecraft Launcher

Hey,

everytime I opened my launcher it said that i am offline, but when I started the game then I could play on servers without any problems. There was only one problem. I had no skin in Single Player Mode. So I decided to take action and signed out to log in again. And now I can not even log in. It always says that I should check my internet connection but everything is fine with it. The most odd thing about it is that I cant even log in Minecraft.net with my Mojang account. The Log In button is only grey and nothing happens. 

(I was actually able to log in with my phone)

I hope you can help me.