static/frontend/search: update header style on hover

When a user hovers over "Search instead for: ...", all of the text will
turn blue.

For golang/go#47320
For golang/go#44142

Change-Id: I4d4c405b006abe63b92e8bee480f43233fbe33e5
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/341310
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
Reviewed-by: Jamal Carvalho <jamal@golang.org>
diff --git a/static/frontend/search/search.css b/static/frontend/search/search.css
index 3b5f71c..0615b5f 100644
--- a/static/frontend/search/search.css
+++ b/static/frontend/search/search.css
@@ -10,9 +10,12 @@
 .SearchResults-instead {
   font-size: 1.25rem;
 }
-.SearchResults-instead span {
+.SearchResults-insteadPrefix {
   color: var(--color-text);
 }
+.SearchResults-instead:hover .SearchResults-insteadPrefix {
+   color: var(--color-brand-primary);
+}
 .SearchResults-summary {
   display: flex;
   flex-direction: column;
diff --git a/static/frontend/search/search.tmpl b/static/frontend/search/search.tmpl
index d2f6d23..833d687 100644
--- a/static/frontend/search/search.tmpl
+++ b/static/frontend/search/search.tmpl
@@ -30,7 +30,7 @@
 {{define "search_identifier"}}
   <h1>Identifiers matching “{{.Query}}”</h1>
   <a class="SearchResults-instead" href="{{.Pagination.URL .Pagination.Limit .SearchModePackage .Query}}">
-    <span>Search instead for </span>“{{.SearchModePackage}}: {{.Query}}”
+    <span class="SearchResults-insteadPrefix">Search instead for </span>“{{.SearchModePackage}}: {{.Query}}”
   </a>
   {{if gt (len .Results) 0}}
     <div class="SearchResults-summary">
@@ -82,7 +82,7 @@
 {{define "search_package"}}
   <h1>Search results for “{{.Query}}”</h1>
   <a class="SearchResults-instead" href="{{.Pagination.URL .Pagination.Limit .SearchModeSymbol .Query}}">
-    <span class="SearchSnippet-symbolPackagePath">Search instead for </span>“{{.SearchModeSymbol}}: {{.Query}}”
+    <span class="SearchResults-insteadPrefix">Search instead for </span>“{{.SearchModeSymbol}}: {{.Query}}”
   </a>
   {{if gt (len .Results) 0}}
     <div class="SearchResults-summary">