Add CSS JavaScript to custom Publishing Page layout
Open Page layout from SharePoint Designer
You can add under "PlaceHolderAdditionalPageHead" or "PlaceHolderMain".
<asp:Content ContentPlaceholderID="PlaceHolderAdditionalPageHead" runat="server">
<style type="text/css">
//some css
</style>
<script type="text/javascript">
//some js
</script>
</asp:Content>
<style type="text/css">
//some css
</style>
<script type="text/javascript">
//some js
</script>
</asp:Content>
----------------------
<asp:Content ContentPlaceholderID="PlaceHolderMain" runat="server">
<style type="text/css">
//some css
</style>
<script type="text/javascript">
//some js
</script>
</asp:Content>
<style type="text/css">
//some css
</style>
<script type="text/javascript">
//some js
</script>
</asp:Content>
