add css-overflow-3.vim and test

after/syntax/css/css-overflow-3.vim

@@ -0,0 +1,4 @@
+" TODO: create cssOverflowProp group and cssOverflowAttr group
+syn match cssFontProp contained "\<max-lines\>"
+syn keyword cssFontAttr contained fragments
+syn match cssFontAttr contained "\<paged-\(x\|y\)\(-controls\)\=\>"

test/test.css

@@ -319,6 +319,14 @@
   column-width: auto;
 }
 
+.overflow {
+  max-lines: paged-x;
+  display: paged-y;
+  display: paged-x-controls;
+  display: paged-y-controls;
+  display: fragments;
+}
+
 .preslev {
   presentation-level: increment;
 }