css changes for better design

src/css/style.css

@@ -27,12 +27,13 @@ input[type="checkbox"] + label {
   background-repeat: no-repeat;
   display: inline-block;
   cursor: pointer;
+  stroke: gray;
 }
 
 input[type="checkbox"]:checked + label {
   transform: scaleX(-1);
   fill: olivedrab;
-  stroke: olivedrab;
+  stroke: olive;
 }
 
 div {