Macbook Air trackpad and keyboard not working

Hi! Last night, I had a VERY minor spill over my keyboard and immediately tilted the computer to get most liquid out and wiped it up. My tabs kept playing properly and everything was working until I realized I was unable to control anything: it was just a you tube video that wouldn't stop playing, so I turned the computer off and on and restarted it, and finally just put it faced down over a towel. Now, the keyboard and track pad don't work but the light under the keyboard is on and everything else is completely fine. What should I do, and if I have to bring it in is there an estimate of cost?