internal/play: fix support for vet errors in playground output

The compile proxy for go.dev/play was not forwarding the Request.WithVet
or Response.VetErrors fields, resulting in no vet errors in the new
playground. Furthermore, it looked like the styling intended for errors
and system messages was not being correctly applied, due to CSS
selectors changing.

Fix both of these bugs, assuming that the broken styling is in fact a
bug.

Result at https://github.com/golang/go/issues/58560#issuecomment-1480044674

Fixes golang/go#58560

Change-Id: If7a9a4323414f4c844e90bd340d93a74e59ce462
Reviewed-on: https://go-review.googlesource.com/c/website/+/478576
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Jamal Carvalho <jamal@golang.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/_content/css/styles.css b/_content/css/styles.css
index 17744612..7e824f23 100644
--- a/_content/css/styles.css
+++ b/_content/css/styles.css
@@ -59,6 +59,7 @@
   --color-text-link: var(--turq-dark);
   --color-text-subtle: var(--gray-4);
   --color-text-inverted: var(--white);
+  --color-text-alert: #aa536c;
   --color-code-comment: var(--green);
 
   /* Interactive Colors */
@@ -102,6 +103,7 @@
   --color-text: var(--gray-9);
   --color-text-link: var(--turq-med);
   --color-text-subtle: var(--gray-7);
+  --color-text-alert: #e67193;
   --color-code-comment: var(--green-light);
 }
 @media (prefers-color-scheme: dark) {
@@ -131,6 +133,7 @@
     --color-text: var(--gray-9);
     --color-text-link: var(--turq-med);
     --color-text-subtle: var(--gray-7);
+    --color-text-alert: #e67193;
     --color-code-comment: var(--green-light);
   }
 }
@@ -4574,6 +4577,12 @@ a.error {
   padding: 0;
   border-radius: 0;
 }
+.Playground-output .stderr {
+  color: var(--color-text-alert);
+}
+.Playground-output .system {
+  color: var(--color-text-subtle);
+}
 .Playground-inputContainer,
 .Playground-input {
   background: var(--color-background-playground-input);
@@ -4886,12 +4895,16 @@ div.play .buttons {
 div.play .buttons .Button {
   margin-left: 0.3125rem;
 }
+
+/* TODO(rsc): are these selectors stale? It looks like they were not ported to go.dev/play.
+ * See for example .Playground-output .stderr. */
 .output .stderr {
   color: #933;
 }
 .output .system {
   color: #999;
 }
+
 .permalink {
   display: none;
 }