modified css file

src/index.css

@@ -32,16 +32,18 @@ to {
   border-bottom: 3px solid transparent;
   border-radius: 5px;
   width: 100%;
-  &:hover {
+}
+
+.btn:hover {
   top: -2px;
   border-bottom: 3px solid black;
 }
-  &:active {
+
+.btn:active {
   top: 3px;
   border-bottom: 0px solid transparent;
   box-shadow: inset 0px 2px 10px -4px black;
 }
-}
 
 .btn-outline-dark:hover {
 color: #212529 !important;