media-tag to less file

customize.dist/src/less2/include/mediatag.less

@@ -0,0 +1,18 @@
+.mediatag_base() {
+    media-tag {
+        min-height: 0;
+        flex: 1;
+        display: flex;
+        flex-flow: column;
+        text-align: center;
+    }
+
+    media-tag img {
+        flex: 1;
+        max-height: 100% !important;
+    }
+
+    media-tag iframe {
+        min-height: 100%;
+    }
+}

www/slide/slide.less

@@ -392,19 +392,6 @@ p {
     //flex: 1;
 }
 
-media-tag {
+@import "../customize/src/less2/include/mediatag.less";
-    min-height: 0;
-    flex: 1;
-    display: flex;
-    flex-flow: column;
-    text-align: center;
-}
 
-media-tag img {
+.mediatag_base();
-    flex: 1;
-    max-height: 100% !important;
-}
-
-media-tag iframe {
-  min-height: 100%;
-}