update animation

animations/trees/iterative/traversal.css

@@ -1,6 +1,6 @@
 @import url('https://fonts.googleapis.com/css?family=Roboto:400,500&display=swap');
 
-/*base styling */
+/* Base styling */
 body {
   margin: 0;
   background-color: #f7f8fa;
@@ -8,7 +8,7 @@ body {
   color: #333;
 }
 
-/*layout containers */
+/* Layout containers */
 #main-container {
   display: flex;
   width: 90%;
@@ -36,7 +36,7 @@ body {
   box-sizing: border-box;
 }
 
-/*stack title */
+/* Stack title */
 #stack-title {
   font-size: 20px;
   text-align: center;
@@ -44,7 +44,7 @@ body {
   color: #555;
 }
 
-/*controls */
+/* Controls */
 #tabs {
   display: flex;
   justify-content: center;
@@ -100,7 +100,7 @@ button:active {
   transform: translateY(1px);
 }
 
-/*status & logs */
+/* Status & logs */
 #status,
 #log,
 #final-seq {