Add +/- button and rearrange button order

index.html

@@ -17,26 +17,29 @@
             
             <button class="clear all">C</button>
             <button class="clear error">CE</button>
+            <button class="plus-minus">+/-</button>
+            <button class="operator">*</button>
+
 
             <button class="num">7</button>
             <button class="num">8</button>
             <button class="num">9</button>
-            <button class="operator">*</button>
+            <button class="operator">/</button>
 
             <button class="num">4</button>
             <button class="num">5</button>
             <button class="num">6</button>
-            <button class="operator">/</button>
+            <button class="operator">-</button>
 
             <button class="num">1</button>
             <button class="num">2</button>
             <button class="num">3</button>
-            <button class="operator">-</button>
+            <button class="operator">+</button>
+
 
             <button class="num">0</button>
             <button class="num">.</button>
             <button class="equal">=</button>
-            <button class="operator">+</button>
         </div>
     </main>
     <footer>

style.css

@@ -63,13 +63,11 @@ button:hover {
     filter: brightness(.9);
 }
 
-.num {
+.num, .plus-minus {
     background: #d9e1f2;
 }
 
 .clear {
-    grid-column: span 2;
-    width: 205px;
     background: #f98383;
 }
 
@@ -78,6 +76,8 @@ button:hover {
 }
 
 .equal {
+    grid-column: span 2;
+    width: 205px;
     background: #79ff54;
 }