브라우저 크기에 맞게 css 폰트사이즈 유동적으로..

viewport sized typography

1vw = 1% of viewport width
1vh = 1% of viewport height
1vmin = 1vw or 1vh, whichever is smaller
1vmax = 1vw or 1vh, whichever is larger

http://css-tricks.com/viewport-sized-typography/