style: prevent text from overflowing its line box (#587)

assets/scss/css/normalize.css

@@ -75,6 +75,7 @@
   
   a {
     background-color: transparent;
+    word-wrap: break-word;
   }
   
   /**
@@ -346,4 +347,4 @@
   
   [hidden] {
     display: none;
-  }
+  }