_content/css: improve playground page margins

Fixes golang/go#56518.

Change-Id: Ia9a55046873961b53b031b3ccbf764041ac29e5a
Reviewed-on: https://go-review.googlesource.com/c/website/+/447998
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Jamal Carvalho <jamal@golang.org>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/_content/css/styles.css b/_content/css/styles.css
index 3da7b11..f8f55f0 100644
--- a/_content/css/styles.css
+++ b/_content/css/styles.css
@@ -4332,7 +4332,6 @@
   }
 }
 h1.Playground-title {
-  font-size: 1.5rem;
   line-height: 1.75rem;
   display: inline;
   margin: 0;
@@ -4347,8 +4346,21 @@
   margin-left: 1rem;
 }
 .PlayPage .Playground-controls {
-  margin-top: 1rem;
-  margin-bottom: 1rem;
+  align-items: start;
+  flex-direction: column;
+  gap: 1rem;
+  margin-bottom: 1.5rem;
+  margin-top: 1.5rem;
+  padding: 0 1rem;
+}
+@media only screen and (min-width: 57.7rem) {
+  .PlayPage .Playground-controls {
+    align-items: initial;
+    flex-direction: row;
+    margin-bottom: 1.5rem;
+    margin-top: 3rem;
+    padding: 0;
+  }
 }
 .linedtextarea .lines {
   float: left;