To respond to Geert Melotte, CSS Flexbox can certainly mess with expectations about source order versus read/tab order. But so can CSS Grid, floats, and absolute positioning.
I follow two rules (for now) when it comes to using flex: 1. I do not use the order property, as that can be a can of worms; and 2. I still tab through the page to see if it makes sense contextually.
I tracked some different browser behaviors in a post with a bunch of code samples: http://adrianroselli.com/2015/10/html-source-order-vs-css-display-order.html
To respond to Geert Melotte, CSS Flexbox can certainly mess with expectations about source order versus read/tab order. But so can CSS Grid, floats, and absolute positioning.
I follow two rules (for now) when it comes to using flex: 1. I do not use the order property, as that can be a can of worms; and 2. I still tab through the page to see if it makes sense contextually.
I tracked some different browser behaviors in a post with a bunch of code samples: http://adrianroselli.com/2015/10/html-source-order-vs-css-display-order.html