fix(client): fix broken background in source code in light mode (#605)

Author: fushar

judgels-client/src/components/SourceCode/SourceCode.scss

@@ -5,6 +5,12 @@ pre.source-code {
   background-color: #f5f5f5 !important;
   overflow-y: auto !important;
 
+  .bp5-light & {
+    .token {
+      background-color: inherit !important;
+    }
+  }
+
   .bp5-dark & {
     border-color: #202b33;
     background-color: #293742 !important;