use xs for columns for narrow screens

index.html

@@ -116,7 +116,7 @@
 
 		<div class="row">
 
-			<div class="col-md-4">
+			<div class="col-xs-4">
 				<h4>
 					Inputs
 				</h4>
@@ -130,7 +130,7 @@
 				></div>
 			</div>
 
-			<div class="col-md-4">
+			<div class="col-xs-4">
 				<h4>
 					Pipeline
 				</h4>
@@ -144,7 +144,7 @@
 				></div>
 			</div>
 
-			<div class="col-md-4">
+			<div class="col-xs-4">
 				<h4>
 					Output
 					<small ng-if="isRunning"> (running ...) </small>