diff --git a/core-list.html b/core-list.html
index 1b41a76..12189ba 100644
--- a/core-list.html
+++ b/core-list.html
@@ -547,6 +547,7 @@
       if (getComputedStyle(this._target).position == 'static') {
         this._target.style.position = 'relative';
       }
+      this._target.style.boxSizing = this._target.style.mozBoxSizing = 'border-box';
       this.style.overflowY = (target == this) ? 'auto' : null;
     },
 
@@ -615,9 +616,9 @@
         if (!this.width) {
           throw 'Grid requires the `width` property to be set';
         }
-        this._rowFactor = Math.floor(this._target.offsetWidth / this.width) || 1;
         var cs = getComputedStyle(this._target);
         var padding = parseInt(cs.paddingLeft || 0) + parseInt(cs.paddingRight || 0);
+        this._rowFactor = Math.floor((this._target.offsetWidth - padding) / this.width) || 1;
         this._rowMargin = (this._target.offsetWidth - (this._rowFactor * this.width) - padding) / 2;
       } else {
         this._rowFactor = 1;
@@ -1058,7 +1059,7 @@
               divider.style.width = this.width * this._rowFactor + 'px';
             }
             divider.style.transform = divider.style.webkitTransform =
-              'translate3d(' + x + 'px,' + y + 'px,0)';
+              'translate(' + x + 'px,' + y + 'px)';
             divider._translateX = x;
             divider._translateY = y;
           }
@@ -1068,7 +1069,7 @@
         if (physicalItem._translateX != x || physicalItem._translateY != y) {
           physicalItem.style.opacity = 1;
           physicalItem.style.transform = physicalItem.style.webkitTransform =
-            'translate3d(' + x + 'px,' + y + 'px,0)';
+            'translate(' + x + 'px,' + y + 'px)';
           physicalItem._translateX = x;
           physicalItem._translateY = y;
         }