MacBook Air is broken

My Macbook isn’t working. It stated with a a little curved lined on the top left of my screen. I thought nothing of it. but then i saw this line come down straight through the middle. Every second it would move little by little until it was down to the left middle of my screen. Then another line appeared in the top right. I was already pretty confused when the lines started but then my computer just stopped working. I can open it and the keyboard lights up and everything but the screen is lit up black (i don’t know how to explain it). If anyone has any solutions please help.