Add styles for cost display

Author: lulunac27a

src/components/CostDisplay/CostDisplay.js

@@ -4,7 +4,7 @@ import styles from './CostDisplay.module.css';
 
 const CostDisplay = ({ cost }) => (
   <div className={styles.CostDisplay} data-testid="CostDisplay">
-    Cost: {cost}
+    Cost: <div id="cost-value">{cost}</div>
   </div>
 );
 

src/components/CostDisplay/CostDisplay.module.css

@@ -1,2 +1,6 @@
 .CostDisplay {
+  text-align: center;
+}
+#cost-value {
+  font-weight: bold;
 }