udpated css for button spacing

Author: riknos314

runestone/common/css/runestone-custom-sphinx-bootstrap.css

@@ -162,7 +162,7 @@ input[type="button"].btn.btn-sm {
 }
 
 .btn {
-    margin: 5px 0;
+    margin: 5px;
 }
 
 .btn.disabled {
@@ -186,6 +186,11 @@ input[type="button"].btn.btn-sm {
     color: #fff;
 }
 
+input[type="radio"],
+input[type="checkbox"] {
+    margin-right: 5px;
+}
+
 .tooltip {
     z-index: 2000 !important;
 }