fix: make the footer always stick to the bottom

css/main.css

@@ -7,6 +7,26 @@ body {
     color: #000000;
 }
 
+html {
+    height: 100%;
+}
+
+body {
+    display: -webkit-box;
+    display: -webkit-flex;
+    display: -moz-box;
+    display: -ms-flexbox;
+    display: flex;
+    -webkit-box-orient: vertical;
+    -webkit-box-direction: normal;
+    -webkit-flex-direction: column;
+       -moz-box-orient: vertical;
+       -moz-box-direction: normal;
+        -ms-flex-direction: column;
+            flex-direction: column;
+    min-height: 100%;
+}
+
 .wrapper {
     width: 100%;
     max-width: 1440px;
@@ -264,6 +284,11 @@ section.hero form.search-form {
 
 main {
     padding: 0.5em;
+    -webkit-box-flex: 1;
+    -webkit-flex-grow: 1;
+       -moz-box-flex: 1;
+        -ms-flex-positive: 1;
+            flex-grow: 1;
 }
 
 main.content {