Set border-box globally instead

less/buttons.less

@@ -87,7 +87,6 @@
   width: 100%;
   padding-left: 0;
   padding-right: 0;
-  .box-sizing(border-box);
 }
 
 // Vertically space out multiple block buttons

less/forms.less

@@ -55,7 +55,6 @@ input[type="search"],
 input[type="tel"],
 input[type="color"] {
   display: inline-block;
-  .box-sizing(border-box); // Makes inputs behave like true block-level elements
   min-height: @input-height-base; // Make inputs at least the height of their button counterpart (base line-height + padding + border)
   padding: 6px 9px;
   // margin-bottom: @line-height-base / 2;

less/grid.less

@@ -18,10 +18,6 @@
   min-height: 1px;
   padding-left:  @grid-gutter-width / 2;
   padding-right: @grid-gutter-width / 2;
-  // Proper box-model (padding doesn't add to width)
-  -webkit-box-sizing: border-box;
-     -moz-box-sizing: border-box;
-          box-sizing: border-box;
 }
 
 // Responsive: Tablets and up

less/progress-bars.less

@@ -62,7 +62,6 @@
   text-shadow: 0 -1px 0 rgba(0,0,0,.25);
   background-color: @progress-bar-bg;
   .box-shadow(inset 0 -1px 0 rgba(0,0,0,.15));
-  .box-sizing(border-box);
   .transition(width .6s ease);
 }
 

less/scaffolding.less

@@ -3,6 +3,16 @@
 // --------------------------------------------------
 
 
+// Reset the box-sizing
+// -------------------------
+
+* {
+  -webkit-box-sizing: border-box;
+     -moz-box-sizing: border-box;
+          box-sizing: border-box;
+}
+
+
 // Body reset
 // -------------------------