add block level input mixin for border-box box-sizing

less/mixins.less

@@ -107,6 +107,7 @@
   white-space: nowrap;
 }
 
+
 // FONTS
 // --------------------------------------------------
 
@@ -142,9 +143,19 @@
 }
 
 
-// Form field states (used in forms.less)
+// FORMS
 // --------------------------------------------------
 
+// Block level inputs
+.input-block-level {
+  display: block;
+  width: 100%;
+  min-height: 28px; /* Make inputs at least the height of their button counterpart */
+  /* Makes inputs behave like true block-level elements */
+  .box-sizing(border-box);
+}
+
+
 // Mixin for form field states
 .formFieldState(@textColor: #555, @borderColor: #ccc, @backgroundColor: #f5f5f5) {
   // Set the text color