Fix css for other highlighting themes. #3945

app/assets/stylesheets/highlight/dark.scss

@@ -92,12 +92,16 @@
   .il { color: #de935f } /* Literal.Number.Integer.Long */
 
   .line_holder {
+    &.parallel .new.new_line,
+    &.parallel .new.line_content,
     &.new .old_line,
     &.new .new_line,
     &.new .line_content {
       @include diff_background(255, 255, 255, #808080);
     }
 
+    &.parallel .old.old_line,
+    &.parallel .old.line_content,
     &.old .old_line,
     &.old .new_line,
     &.old .line_content {

app/assets/stylesheets/highlight/solarized_dark.scss

@@ -113,12 +113,16 @@
   .il { color: #2aa198 } /* Literal.Number.Integer.Long */
 
   .line_holder {
+    &.parallel .new.new_line,
+    &.parallel .new.line_content,
     &.new .old_line,
     &.new .new_line,
     &.new .line_content {
       @include diff_background(255, 255, 255, #808080);
     }
 
+    &.parallel .old.old_line,
+    &.parallel .old.line_content,
     &.old .old_line,
     &.old .new_line,
     &.old .line_content {

app/assets/stylesheets/highlight/solarized_light.scss

@@ -114,12 +114,16 @@
 
 
   .line_holder {
+    &.parallel .new.new_line,
+    &.parallel .new.line_content,
     &.new .old_line,
     &.new .new_line,
     &.new .line_content {
       @include diff_background(92, 164, 169, #FAF3DD);
     }
 
+    &.parallel .old.old_line,
+    &.parallel .old.line_content,
     &.old .old_line,
     &.old .new_line,
     &.old .line_content {