fix search box css in dark theme

embark-ui/src/components/search.css

@@ -1,11 +1,13 @@
-.search-bar input {
+#root .search-bar input {
   border-top-right-radius: 0;
   border-bottom-right-radius: 0;
   border: 0;
   outline: none;
+  box-shadow: none;
 }
 
-.search-bar button {
+#root .search-bar button {
   border-top-left-radius: 0;
   border-bottom-left-radius: 0;
+  box-shadow: none;
 }

embark-ui/src/dark-theme/bootstrap/_buttons.scss

@@ -141,3 +141,8 @@ input[type="button"] {
     width: 100%;
   }
 }
+
+.search-bar button {
+  background-color: $gray-500;
+  border-color: $gray-500;
+}

embark-ui/src/dark-theme/bootstrap/_reboot.scss

@@ -65,7 +65,7 @@ article, aside, figcaption, figure, footer, header, hgroup, main, nav, section {
   background-color: $body-bg; // 2
 }
 
-span.fa {
+.dropdown-item span.fa {
   display: inline-block;
   width: 20px;
   margin-right: 10px;