_content: change Go headline on go.dev

The old one (“Build fast, reliable, and efficient software at scale”)
is missing "simple" and "secure"; also "fast" and "efficient" are synonyms.

Change-Id: I50e6bb524e5095d88b4b71f644c3653da98712ff
Reviewed-on: https://go-review.googlesource.com/c/website/+/451297
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>
diff --git a/_content/css/styles.css b/_content/css/styles.css
index ff8f0a8..cbb454f 100644
--- a/_content/css/styles.css
+++ b/_content/css/styles.css
@@ -1360,7 +1360,7 @@
   }
   .Hero-blurb {
     grid-column: 1 / 2;
-    margin: 2.5rem auto 0;
+    margin: 2.5rem 0 0;
   }
   .Hero-gopher {
     grid-row: 1 / 3;
diff --git a/_content/index.md b/_content/index.md
index 1dbeb47..e346227 100644
--- a/_content/index.md
+++ b/_content/index.md
@@ -1,6 +1,6 @@
 ---
 title: The Go Programming Language
-summary: Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
+summary: Go is an open source programming language that makes it simple to build secure, scalable systems.
 ---
 
 {{$canShare := not googleCN}}
@@ -8,19 +8,19 @@
 <section class="Hero bluebg">
   <div class="Hero-gridContainer">
     <div class="Hero-blurb">
-      <h1>Build fast, reliable, and efficient software at scale</h1>
+      <h1>Build simple, secure, scalable systems with Go</h1>
       <ul class="Hero-blurbList">
         <li>
           <svg width="12" height="10" viewBox="0 0 12 10" fill="none" xmlns="http://www.w3.org/2000/svg">
             <path d="M10.8519 0.52594L3.89189 7.10404L1.14811 4.51081L0 5.59592L3.89189 9.27426L12 1.61105L10.8519 0.52594Z" fill="white" fill-opacity="0.87">
           </svg>
-          Go is an open source programming language supported by Google
+          An open-source programming language supported by Google
         </li>
         <li>
           <svg width="12" height="10" viewBox="0 0 12 10" fill="none" xmlns="http://www.w3.org/2000/svg">
             <path d="M10.8519 0.52594L3.89189 7.10404L1.14811 4.51081L0 5.59592L3.89189 9.27426L12 1.61105L10.8519 0.52594Z" fill="white" fill-opacity="0.87">
           </svg>
-          Easy to learn and get started with
+          Easy to learn and great for teams
         </li>
         <li>
           <svg width="12" height="10" viewBox="0 0 12 10" fill="none" xmlns="http://www.w3.org/2000/svg">
@@ -32,7 +32,7 @@
           <svg width="12" height="10" viewBox="0 0 12 10" fill="none" xmlns="http://www.w3.org/2000/svg">
             <path d="M10.8519 0.52594L3.89189 7.10404L1.14811 4.51081L0 5.59592L3.89189 9.27426L12 1.61105L10.8519 0.52594Z" fill="white" fill-opacity="0.87">
           </svg>
-          Growing ecosystem of partners, communities, and tools
+          Large ecosystem of partners, communities, and tools
         </li>
       </ul>
     </div>
diff --git a/cmd/golangorg/testdata/godev.txt b/cmd/golangorg/testdata/godev.txt
index a85ef48..fd68e06 100644
--- a/cmd/golangorg/testdata/godev.txt
+++ b/cmd/golangorg/testdata/godev.txt
@@ -1,5 +1,5 @@
 GET https://go.dev/
-body contains Go is an open source programming language supported by Google
+body contains An open-source programming language supported by Google
 body contains <h2 class="WhoUses-headerH2">Companies using Go</h2>
 
 GET https://go.dev/about