diff --git a/src/ui/flat/block.css b/src/ui/flat/block.css
index 59ccef868..9e4b5a3a6 100755
--- a/src/ui/flat/block.css
+++ b/src/ui/flat/block.css
@@ -238,3 +238,24 @@
   color: #AD0000;
   border-color: #B06C6C;
 }
+
+
+/*--------------
+     Sizes 
+---------------*/
+
+.ui.small.block {
+  font-size: 14px;
+}
+.ui.block {
+  font-size: 16px;
+}
+.ui.large.block {
+  font-size: 18px;
+}
+.ui.huge.block {
+  font-size: 24px;
+}
+.ui.massive.block {
+  font-size: 32px;
+}
\ No newline at end of file