board with 9 squares

src/App.js

@@ -3,8 +3,21 @@ import './App.css';
 function App() {
   return (
   <>
-    <button className="square">X</button>
-    <button className="square">X</button>
+  <div className="board-row">
+    <button className="square">1</button>
+    <button className="square">2</button>
+    <button className="square">3</button>
+  </div>
+  <div className="board-row">
+    <button className="square">4</button>
+    <button className="square">5</button>
+    <button className="square">6</button>
+  </div>
+  <div className="board-row">
+    <button className="square">7</button>
+    <button className="square">8</button>
+    <button className="square">9</button>
+  </div>
   </>
   );
 }

src/index.css

@@ -25,4 +25,10 @@ code {
   padding: 0;
   text-align: center;
   width: 34px;
+}
+
+.board-row:after {
+  clear: both;
+  content: '';
+  display: table;
 }