Responsive tweaks and refactoring

app/less/modal.less

@@ -16,8 +16,7 @@
   left:50%; top:50%;
   transform:translate(-50%,-50%);
   -webkit-transform:translate(-50%,-50%);
-  width: 75%;
-  max-width: 1000px;
+  width: 800px;
   max-height: 100%;
   padding: 2em;
   background-color: @bgBlack;
@@ -27,6 +26,10 @@
   -webkit-overflow-scrolling: touch;
 
   .smallTablet({
+    width: 90%;
+  });
+
+  .largePhone({
     padding: 1em;
     width: 100%;
   });