Fix content jump of tags on small screens

assets/sass/_flex.scss

@@ -13,3 +13,9 @@
 .flex-direction-column {
     flex-direction: column;
 }
+
+.flex-sm-direction-column {
+    @media (max-width: $sm) {
+        flex-direction: column;
+    }
+}

layouts/snippets/single.html

@@ -1,7 +1,7 @@
 {{ define "main" }}
 
 <h1>{{ .Title }}</h1>
-<div class="flex flex-spread">
+<div class="flex flex-spread flex-sm-direction-column">
     <span>Published on {{ .Date.Format "January 2, 2006" }}</span>
     <span>
         {{ range .Params.Tags }}