make output row flexbox so operator buttons don't get huge on zoom

index.html

@@ -10,9 +10,8 @@
 			<label for="expr">Expression</label>
 			<input id="expr" required type="text" />
 
+			<div id="result-row">
 				<output id="result" for="expr modulus"></output>
-
-			<div id="modulus-entry">
 				<label for="modulus">mod</label>
 				<input id="modulus" required type="number" min="1" step="1" />
 			</div>

styles.css

@@ -17,17 +17,21 @@ label[for="expr"] {
 	text-align: right;
 }
 
-#modulus-entry {
-	grid-column: 4;
+#result-row {
+	grid-column: 1 / 5;
 	display: flex;
 }
 
+#result {
+	flex: auto;
+}
+
 #modulus-entry label {
 	flex: initial;
 }
 
 #modulus {
-	flex: auto;
+	flex: initial;
 }
 
 #extra-buttons {