[Glitch] Refactor scss

Port 480131a376 to glitch-soc

app/javascript/flavours/glitch/styles/components/index.scss

@@ -355,14 +355,19 @@
   position: relative;
   width: 100%;
   height: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
 
-  &.image-loader--loading {
-    display: flex;
-    align-content: center;
+  .image-loader__preview-canvas {
+    max-width: $media-modal-media-max-width;
+    max-height: $media-modal-media-max-height;
+    background: url('~images/void.png') repeat;
+    object-fit: contain;
+  }
 
-    .image-loader__preview-canvas {
-      filter: blur(2px);
-    }
+  &.image-loader--loading .image-loader__preview-canvas {
+    filter: blur(2px);
   }
 
   &.image-loader--amorphous .image-loader__preview-canvas {
@@ -375,7 +380,16 @@
   width: 100%;
   height: 100%;
   display: flex;
-  align-content: center;
+  align-items: center;
+  justify-content: center;
+
+  img {
+    max-width: $media-modal-media-max-width;
+    max-height: $media-modal-media-max-height;
+    width: auto;
+    height: auto;
+    object-fit: contain;
+  }
 }
 
 .dropdown {

app/javascript/flavours/glitch/styles/components/media.scss

@@ -167,27 +167,6 @@
   width: 100%;
   height: 100%;
   position: relative;
-
-  img,
-  canvas,
-  video {
-    max-width: 100%;
-    /*
-    put margins on top and bottom of image to avoid the screen coverd by
-    image.
-     */
-    max-height: 80%;
-    width: auto;
-    height: auto;
-    margin: auto;
-  }
-
-  img,
-  canvas {
-    display: block;
-    background: url('~images/void.png') repeat;
-    object-fit: contain;
-  }
 }
 
 .media-modal__closer {

app/javascript/flavours/glitch/styles/variables.scss

@@ -31,6 +31,11 @@ $ui-highlight-color: $classic-highlight-color !default;        // Vibrant
 // Language codes that uses CJK fonts
 $cjk-langs: ja, ko, zh-CN, zh-HK, zh-TW;
 
+// Variables for components
+$media-modal-media-max-width: 100%;
+// put margins on top and bottom of image to avoid the screen covered by image.
+$media-modal-media-max-height: 80%;
+
 // Avatar border size (8% default, 100% for rounded avatars)
 $ui-avatar-border-size: 8%;