Zitatformatierung: Auf kontrastreiche Darstellung anpassen

Closes #1375

Merge request studip/studip!1253

resources/assets/stylesheets/scss/blockquote.scss

+blockquote {
+    background-color: $dark-gray-color-5;
+    border-left: 3px solid $base-color;
+    padding: 4px 10px;
+    margin: 0 0 8px;
+    color: black;
+    > .author {
+        margin-bottom: 4px;
+        color: black;
+        font-weight: 600;
+    }
+    blockquote {
+        background-color: white;
+        blockquote {
+            background-color: $dark-gray-color-5;
+            blockquote {
+                background-color: white;
+            }
+        }
+    }
+}
\ No newline at end of file

resources/assets/stylesheets/scss/blubber.scss

@@ -207,9 +207,6 @@
                     > .name {
                         display: none;
                     }
-                    blockquote {
-                        background-color: rgba(255, 255, 255, 0.1);
-                    }
                 }
                 > .avatar {
                     display: none;

resources/assets/stylesheets/studip.scss

@@ -18,6 +18,7 @@
 @import "scss/avatar";
 @import "scss/badges";
 @import "scss/big-image-handler";
+@import "scss/blockquote.scss";
 @import "scss/blubber";
 @import "scss/buttons";
 @import "scss/clipboard";
@@ -122,18 +123,4 @@
     display: none;
 }
 
-blockquote {
-    border-left: 3px solid $brand-color-lighter;
-    padding: 5px 5px 5px 8px;
-    margin: 8px 8px 8px 0;
-
-    background-color: rgba(0,0,0,0.05);
-    > .author {
-        background-color: $brand-color-lighter;
-        color: $white;
-        padding: 4px 4px 4px 15px;
-        margin: -5px -5px 5px -10px;
-    }
-}
-
 div.indent { margin-left: 2em; }