Refactor flex from flex-spread

assets/sass/_flex.scss

@@ -1,8 +1,15 @@
-.flex-spread {
+.flex {
     display: flex;
+}
+
+.flex-spread {
     justify-content: space-between;
 }
 
+.flex-center {
+    justify-content: center;
+}
+
 .flex-direction-column {
     flex-direction: column;
 }

layouts/snippets/single.html

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