Where to style tag <style> in AllItems.aspx when edited in Sharepoint Designer

Question

Below is the List view (AllItems.aspx) code:

<%@ Page language="C#" MasterPageFile="~masterurl/default.master"    Inherits="Microsoft.SharePoint.WebPartPages.WebPartPage,Microsoft.SharePoint,Version=16.0.0.0,Culture=neutral,PublicKeyToken=71e9bce111e9429c" meta:progid="SharePoint.WebPartPage.Document" meta:webpartpageexpansion="full"  %>
<%@ Register Tagprefix="SharePoint" Namespace="Microsoft.SharePoint.WebControls" Assembly="Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Register Tagprefix="Utilities" Namespace="Microsoft.SharePoint.Utilities" Assembly="Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Import Namespace="Microsoft.SharePoint" %> <%@ Assembly Name="Microsoft.Web.CommandUI, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Register Tagprefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages" Assembly="Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register Tagprefix="ApplicationPages" Namespace="Microsoft.SharePoint.ApplicationPages.WebControls" Assembly="Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<asp:Content ContentPlaceHolderId="PlaceHolderPageTitle" runat="server">
    <SharePoint:ListProperty Property="TitleOrFolder" runat="server"/> - 
    <SharePoint:ListProperty Property="CurrentViewTitle" runat="server"/></asp:Content>
<asp:content contentplaceholderid="PlaceHolderAdditionalPageHead" runat="server">
    <SharePoint:RssLink runat="server"/>
</asp:content>
<asp:Content ContentPlaceHolderId="PlaceHolderPageImage" runat="server">
    <SharePoint:ViewIcon Width="145" Height="54" runat="server"/></asp:Content>
<asp:Content ContentPlaceHolderId="PlaceHolderLeftActions" runat="server">
<SharePoint:RecentChangesMenu runat="server" id="RecentChanges"/>
<SharePoint:ModifySettingsLink runat="server"/>
</asp:Content>
<asp:Content ContentPlaceHolderId ="PlaceHolderBodyLeftBorder" runat="server">
 <div height="100%" class="ms-pagemargin"><img src="/_layouts/15/images/blank.gif?rev=47" width='6' height='1' alt="" data-accessibility-nocheck="true"/></div>
</asp:Content>
<asp:Content ContentPlaceHolderId="PlaceHolderMain" runat="server">
        <WebPartPages:WebPartZone runat="server" FrameType="None" ID="Main" Title="loc:Main"><ZoneTemplate><WebPartPages:XsltListViewWebPart runat="server" ViewFlag="" ViewSelectorFetchAsync="False" InplaceSearchEnabled="True" ServerRender="False" ClientRender="True" InitialAsyncDataFetch="False" WebId="00000000-0000-0000-0000-000000000000" IsClientRender="False" GhostedXslLink="main.xsl" ViewGuid="{88EB8983-FE22-42E5-AEB1-DF241D797744}" EnableOriginalValue="False" DisplayName="All Items" ViewContentTypeId="" Default="TRUE" ListName="{AEAD64D6-FB90-4A4C-9E21-2D5BB8D33AD4}" ListId="aead64d6-fb90-4a4c-9e21-2d5bb8d33ad4" PageType="PAGE_DEFAULTVIEW" PageSize="-1" UseSQLDataSourcePaging="True" DataSourceID="" ShowWithSampleData="False" AsyncRefresh="False" ManualRefresh="False" AutoRefresh="False" AutoRefreshInterval="60" Title="Mianwali | IFC | BioMedical" FrameType="Default" SuppressWebPartChrome="False" Description="" IsIncluded="True" ZoneID="Main" PartOrder="1" FrameState="Normal" AllowRemove="True" AllowZoneChange="True" AllowMinimize="True" AllowConnect="True" AllowEdit="True" AllowHide="True" IsVisible="True" TitleUrl="/sites/testsite2/Lists/Mianwali-IFC-Biomed" DetailLink="/sites/testsite2/Lists/Mianwali-IFC-Biomed" HelpLink="" HelpMode="Modeless" Dir="Default" PartImageSmall="" MissingAssembly="Cannot import this Web Part." PartImageLarge="" IsIncludedFilter="" ExportControlledProperties="False" ConnectionID="00000000-0000-0000-0000-000000000000" ID="g_88eb8983_fe22_42e5_aeb1_df241d797744" ExportMode="NonSensitiveData" __MarkupType="vsattributemarkup" __WebPartId="{88EB8983-FE22-42E5-AEB1-DF241D797744}" __AllowXSLTEditing="true" __designer:CustomXsl="Fldtypes_mswhTitle.xsl;fldtypes_Ratings.xsl" WebPart="true" Height="" Width=""><ParameterBindings>

  <ParameterBinding Name="dvt_sortdir" Location="Postback;Connection"/>
            <ParameterBinding Name="dvt_sortfield" Location="Postback;Connection"/>
            <ParameterBinding Name="dvt_startposition" Location="Postback" DefaultValue=""/>
            <ParameterBinding Name="dvt_firstrow" Location="Postback;Connection"/>
            <ParameterBinding Name="OpenMenuKeyAccessible" Location="Resource(wss,OpenMenuKeyAccessible)" />
            <ParameterBinding Name="open_menu" Location="Resource(wss,open_menu)" />
            <ParameterBinding Name="select_deselect_all" Location="Resource(wss,select_deselect_all)" />
            <ParameterBinding Name="idPresEnabled" Location="Resource(wss,idPresEnabled)" /><ParameterBinding Name="NoAnnouncements" Location="Resource(wss,noXinviewofY_LIST)" /><ParameterBinding Name="NoAnnouncementsHowTo" Location="Resource(wss,noXinviewofY_DEFAULT)" /></ParameterBindings>
<DataFields>
</DataFields>
<XmlDefinition>
<View Name="{88EB8983-FE22-42E5-AEB1-DF241D797744}" DefaultView="TRUE" MobileView="TRUE" MobileDefaultView="TRUE" Type="HTML" DisplayName="All Items" Url="/sites/testsite2/Lists/Mianwali-IFC-Biomed/AllItems.aspx" Level="1" BaseViewID="1" ContentTypeID="0x" ImageUrl="/_layouts/15/images/generic.png?rev=47" ><Query><OrderBy><FieldRef Name="ID"/></OrderBy></Query><ViewFields><FieldRef Name="IFC_x0020_No"/><FieldRef Name="LinkTitle"/><FieldRef Name="Revision_x0020_No"/><FieldRef Name="Description"/><FieldRef Name="Attachments"/></ViewFields><RowLimit Paged="TRUE">30</RowLimit><Aggregations Value="Off"/><JSLink>clienttemplates.js</JSLink><XslLink Default="TRUE">main.xsl</XslLink><CustomFormatter/><Toolbar Type="Standard"/></View></XmlDefinition>
</WebPartPages:XsltListViewWebPart>

</ZoneTemplate></WebPartPages:WebPartZone>
</asp:Content>
<asp:Content ContentPlaceHolderId="PlaceHolderPageDescription" runat="server">
<SharePoint:ListProperty CssClass="ms-listdescription" Property="Description" runat="server"/>
</asp:Content>
<asp:Content ContentPlaceHolderId="PlaceHolderCalendarNavigator" runat="server">
  <SharePoint:SPCalendarNavigator id="CalendarNavigatorId" runat="server"/>
  <ApplicationPages:CalendarAggregationPanel id="AggregationPanel" runat="server"/>
</asp:Content>

Where should I put <style></style> tag. I do not want to add content editor/script editor webparts. We can place <script></script> tag below <asp:Content ContentPlaceHolderId="PlaceHolderMain" runat="server"> but if Style tag is added it does not work

Answer 1

Under PlaceHolderMain is also available for style tag:

<asp:Content ContentPlaceHolderId="PlaceHolderMain" runat="server">
<script type="text/javascript">
alert("Hello");
</script>

<style type="text/css">

#s4-workspace {
    background-color:black;
}
</style>