--- a/css/tram-im.css	Fri Dec 16 22:12:18 2016 +0800
+++ b/css/tram-im.css	Sat Dec 17 02:11:26 2016 +0800
@@ -29,6 +29,9 @@
 .has-sidebar.mini {
     padding-left: 42px;
 }
+.full-height {
+    min-height: 100vh;
+}
 .sidebar {
     background: #333;
     width: 200px;

--- a/index.html	Fri Dec 16 22:12:18 2016 +0800
+++ b/index.html	Sat Dec 17 02:11:26 2016 +0800
@@ -69,7 +69,7 @@
       $('[data-step="noscript"]').addClass('uk-hidden');
     </script>
 
-    <div class="has-sidebar uk-hidden" data-step="main">
+    <div class="has-sidebar full-height uk-hidden" data-step="main">
       <div class="sidebar" data-app="sidebar" rv-class-mini="model:sidebar/minified">
         <ul class="uk-nav uk-nav-offcanvas uk-text-nowrap">
           <li class="uk-text-center">