diff --git a/share/base.css b/share/base.css
index cc27d01..d4cdc7d 100644
--- a/share/base.css
+++ b/share/base.css
@@ -1,5 +1,8 @@
 /* Base CSS */
 /* by Wang Lu */
+body {
+  position:relative;
+}
 #pdf-main {
   position:absolute;
   top:0;
diff --git a/src/HTMLRenderer/export.cc b/src/HTMLRenderer/export.cc
index fa5a706..19df5e5 100644
--- a/src/HTMLRenderer/export.cc
+++ b/src/HTMLRenderer/export.cc
@@ -97,18 +97,27 @@ void HTMLRenderer::export_transform_matrix (long long tm_id, const double * tm)
     // we have already shifted the origin
     
     // TODO: recognize common matices
-    auto prefixes = {"", "-ms-", "-moz-", "-webkit-", "-o-"};
-    for(auto iter = prefixes.begin(); iter != prefixes.end(); ++iter)
+    if(_tm_euqal(tm, id_matrix, 4))
     {
-        const auto & prefix = *iter;
-        // PDF use a different coordinate system from Web
-        css_fout << prefix << "transform:matrix("
-            << _round(tm[0]) << ','
-            << _round(-tm[1]) << ','
-            << _round(-tm[2]) << ','
-            << _round(tm[3]) << ',';
+        auto prefixes = {"", "-ms-", "-moz-", "-webkit-", "-o-"};
+        for(auto iter = prefixes.begin(); iter != prefixes.end(); ++iter)
+            css_fout << prefix << "transform:none;";
+    }
+    else
+    {
+        auto prefixes = {"", "-ms-", "-moz-", "-webkit-", "-o-"};
+        for(auto iter = prefixes.begin(); iter != prefixes.end(); ++iter)
+        {
+            const auto & prefix = *iter;
+            // PDF use a different coordinate system from Web
+            css_fout << prefix << "transform:matrix("
+                << _round(tm[0]) << ','
+                << _round(-tm[1]) << ','
+                << _round(-tm[2]) << ','
+                << _round(tm[3]) << ',';
 
-        css_fout << "0,0);";
+            css_fout << "0,0);";
+        }
     }
     css_fout << "}" << endl;
 }