style: improve scrollbar styling on the query editor

This changes makes scrollbars in the graphiql editor transparent, so that they look better integrated in the interface

Author: TPXP

.changeset/transparent-scrollbars.md

@@ -0,0 +1,6 @@
+---
+"@graphiql/react": patch
+"graphiql": patch
+---
+
+style: improve scrollbar styling on the query editor

packages/graphiql-react/src/style/root.css

@@ -146,3 +146,31 @@ body.graphiql-dark [data-radix-popper-content-wrapper] {
     }
   }
 }
+
+/* Transparent scrollbars, without backgrounds */
+.graphiql-container .CodeMirror-hscrollbar,
+.graphiql-container .CodeMirror-vscrollbar {
+  scrollbar-color: #88888888 transparent;
+}
+
+/* The little square between H and V scrollbars */
+.graphiql-container .CodeMirror-scrollbar-filler,
+.graphiql-container .CodeMirror-gutter-filler {
+  background-color: transparent;
+}
+
+/* Safari scrollbars */
+.graphiql-container .CodeMirror-hscrollbar::-webkit-scrollbar-track,
+.graphiql-container .CodeMirror-vscrollbar::-webkit-scrollbar-track,
+.graphiql-container .CodeMirror-hscrollbar::-webkit-scrollbar,
+.graphiql-container .CodeMirror-vscrollbar::-webkit-scrollbar{
+    background-color: transparent;
+}
+
+.graphiql-container .CodeMirror-hscrollbar::-webkit-scrollbar-thumb,
+.graphiql-container .CodeMirror-vscrollbar::-webkit-scrollbar-thumb {
+    border-radius: 99px;
+    padding: 3px;
+    box-shadow: inset 0 0 99px 99px #88888888;
+    border: solid 3px transparent;
+}