one .btn

- group into a single `.btn`
- add spaces for readability

css/css.css

@@ -1,4 +1,4 @@
-h1,h2,h3,h4,h5,h6 {
+h1, h2, h3, h4, h5, h6 {
   font-family: 'Montserrat', sans-serif;
 }
 
@@ -11,7 +11,7 @@ dd {
 }
 
 dt {
-  font-family: Menlo,Monaco,Consolas,"Courier New",monospace;
+  font-family: Menlo, Monaco, Consolas, "Courier New", monospace;
 }
 
 img {
@@ -38,9 +38,6 @@ div {
 
 .btn {
   margin: 8px;
-}
-
-.btn {
   display: inline-block;
   vertical-align: middle;
   -webkit-transform: translateZ(0);
@@ -54,6 +51,7 @@ div {
   -webkit-transition-duration: 0.3s;
   transition-duration: 0.3s;
 }
+
 .btn:before {
   content: "💫";
   position: absolute;
@@ -68,6 +66,7 @@ div {
   -webkit-transition-timing-function: ease-out;
   transition-timing-function: ease-out;
 }
+
 .btn:hover:before, .btn:focus:before, .btn:active:before {
   -webkit-transform: scale(1.3) translateZ(0);
   transform: scale(1.3) translateZ(0);