The flex property is a shorthand for the flex-grow, flex-shrink, and flex-basis attributes, as we all know. The default value is 0 1 auto, which implies it has no effect.
flex-grow: 0;
flex-shrink: 1;
flex-basis: auto;
However, I've seen that flex: 1 is utilised in a lot of places. Is 1 1 auto or 1 0 auto abbreviated? I'm not sure what that signifies, and a Google search yields nothing.