浮动 位置修改

@@ -66,7 +66,7 @@ exports.init = function() {
                 thumbContainer
                     .addClass('fixed-bottom')
                     .removeClass('static');
-            } else if (sTop <= containerTop) {
+            } else if (sTop > containerTop - wH + tContainerH) {
                 thumbContainer
                     .addClass('static')
                     .removeClass('fixed-bottom fixed-top');