Add APK download link to landing page

styles.css

@@ -257,6 +257,17 @@ textarea {
     margin: 28px 0 24px;
 }
 
+.download-note {
+    margin: 0;
+    color: var(--muted);
+    font-size: 14px;
+    font-weight: 600;
+}
+
+.download-note-light {
+    color: rgba(255, 255, 255, 0.86);
+}
+
 .btn {
     min-height: 58px;
     padding: 0 24px;