Complex Gradient Background (flexbox + vh)
One "main" full-width gradient followed by compound "footer", made of two half-width blocks.
Made possible with recently-implemented viewport-related units (vw, vh) and not-so-recently-implemented/not-yet-officially-supported Flexbox element positioning.
You can play with flexbox-"order" to make blocks swap places.
"Legacy" implementation: http://cssdeck.com/labs/glvmkxxn