Internal: Created shared styles for list dropdown items to ensure a c…

…onsistent look across the features (see ckeditor/ckeditor5-font#4).

theme/ckeditor5-ui/components/dropdown/listdropdown.css

@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) 2003-2018, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md.
+ */
+
+/* Using absolute units to make sure each element has the same height and padding.
+https://github.com/ckeditor/ckeditor5-heading/issues/63 */
+.ck-dropdown .ck-dropdown__panel .ck-list__item {
+	line-height: calc(.8*var(--ck-line-height-base)*var(--ck-font-size-base));
+	padding: calc(.4*var(--ck-line-height-base)*var(--ck-font-size-base));
+}