stylelint the examples

docs/examples/cover/cover.css

@@ -1,3 +1,5 @@
+/* stylelint-disable property-no-vendor-prefix */
+
 /*
  * Globals
  */
@@ -32,7 +34,7 @@ body {
 body {
   color: #fff;
   text-align: center;
-  text-shadow: 0 1px 3px rgba(0,0,0,.5);
+  text-shadow: 0 1px 3px rgba(0, 0, 0, .5);
 }
 
 /* Extra markup and styles for table-esque vertical and horizontal centering */
@@ -41,8 +43,8 @@ body {
   width: 100%;
   height: 100%; /* For at least Firefox */
   min-height: 100%;
-  -webkit-box-shadow: inset 0 0 100px rgba(0,0,0,.5);
-          box-shadow: inset 0 0 100px rgba(0,0,0,.5);
+  -webkit-box-shadow: inset 0 0 100px rgba(0, 0, 0, .5);
+  box-shadow: inset 0 0 100px rgba(0, 0, 0, .5);
 }
 .site-wrapper-inner {
   display: table-cell;
@@ -77,16 +79,16 @@ body {
   padding-right: 0;
   padding-left: 0;
   font-size: 16px;
-  font-weight: bold;
+  font-weight: 700;
   color: #fff; /* IE8 proofing */
-  color: rgba(255,255,255,.75);
+  color: rgba(255, 255, 255, .75);
   border-bottom: 2px solid transparent;
 }
 .masthead-nav > li > a:hover,
 .masthead-nav > li > a:focus {
   background-color: transparent;
   border-bottom-color: #a9a9a9;
-  border-bottom-color: rgba(255,255,255,.25);
+  border-bottom-color: rgba(255, 255, 255, .25);
 }
 .masthead-nav > .active > a,
 .masthead-nav > .active > a:hover,
@@ -114,7 +116,7 @@ body {
 }
 .cover .btn-lg {
   padding: 10px 20px;
-  font-weight: bold;
+  font-weight: 700;
 }
 
 
@@ -124,7 +126,7 @@ body {
 
 .mastfoot {
   color: #999; /* IE8 proofing */
-  color: rgba(255,255,255,.5);
+  color: rgba(255, 255, 255, .5);
 }
 
 
@@ -142,11 +144,9 @@ body {
     position: fixed;
     bottom: 0;
   }
-  /* Start the vertical centering */
   .site-wrapper-inner {
-    vertical-align: middle;
+    vertical-align: middle; /* Start the vertical centering */
   }
-  /* Handle the widths */
   .masthead,
   .mastfoot,
   .cover-container {