Rearrange center handling css and fix centering of video and audio.

client/css/up1.css

@@ -136,12 +136,12 @@
   max-width: 100%;
 }
 
-#previewimg img {
+#previewimg img, .preview video, .preview audio {
   display: block;
   margin: 0 auto;
 }
 
-#previewimg img:not(.dragged) {
+#previewimg img:not(.dragged), .preview audio, .preview video {
   max-height: 100vh;
   max-width: 100vw;
 }
@@ -324,11 +324,14 @@
   white-space: nowrap;
 }
 
-audio.preview,video.preview,.downloadexplain,#downloadprogress,#previewimg {
+.centertext {
+  text-align: center;
+}
+
+.centerable {
   -webkit-transform: translateY(-50%);
   margin: 0 auto;
   position: relative;
-  text-align: center;
   top: 50%;
   transform: translateY(-50%);
 }

client/js/download.js

@@ -79,7 +79,7 @@ upload.modules.addmodule({
         this._.editpaste.hide()
         this._.newupload.hide()
         this._.content = {}
-        this._.content.main = this._.content.loading = $('<h1>').prop('id', 'downloadprogress').text('Downloading')
+        this._.content.main = this._.content.loading = $('<h1>').prop('id', 'downloadprogress').addClass('centertext centerable').text('Downloading')
         this._.detailsarea.empty().append(this._.content.main)
         this._.deletebtn.hide()
         upload.updown.download(content, this.progress.bind(this), this.downloaded.bind(this))
@@ -192,7 +192,7 @@ upload.modules.addmodule({
         }
 
         if (association == 'image' || association == 'svg') {
-            var imgcontent = $('<div>').prop('id', 'previewimg').addClass('preview').appendTo(this._.detailsarea)
+            var imgcontent = $('<div>').prop('id', 'previewimg').addClass('preview centerable').appendTo(this._.detailsarea)
 
             var previewimg = $('<img>').addClass('dragresize').appendTo(imgcontent).prop('src', url)
       } else if (association == 'text') {
@@ -225,11 +225,11 @@ upload.modules.addmodule({
 
             this._.editpaste.show()
       } else if (association == 'video') {
-            $('<video>').addClass('preview').prop('controls', true).prop('autoplay', true).appendTo(this._.detailsarea).prop('src', url)
+            $('<div>').addClass('preview centerable').append($('<video>').prop('controls', true).prop('autoplay', true).prop('src', url)).appendTo(this._.detailsarea)
       } else if (association == 'audio') {
-            $('<audio>').addClass('preview').prop('controls', true).prop('autoplay', true).appendTo(this._.detailsarea).prop('src', url)
+            $('<div>').addClass('preview centerable').append($('<audio>').prop('controls', true).prop('autoplay', true).prop('src', url)).appendTo(this._.detailsarea)
         } else {
-            $('<div>').addClass('preview').addClass('downloadexplain').text("Click the Download link in the bottom-left to download this file.").appendTo(this._.detailsarea)
+            $('<div>').addClass('preview').addClass('downloadexplain centerable centertext').text("Click the Download link in the bottom-left to download this file.").appendTo(this._.detailsarea)
         }
         this._.filename.show()
         this._.btns.show()