A quick sketch to show how building box shadows creates a richer visual appearance.
box-shadow:
0 4px 20px 0
rgba(0, 0, 0, 0.12);
box-shadow:
0 12px 4px -8px
rgba(0, 0, 0, 0.2);
box-shadow:
0 8px 8px 0
rgba(0, 0, 0, 0.14);
box-shadow:
0 8px 8px 0 rgba(0, 0, 0, 0.14),
0 12px 4px -8px rgba(0, 0, 0, 0.2),
0 4px 20px 0 rgba(0, 0, 0, 0.12);