Default theme implementation to display the basic html structure of a single
$css: An array of CSS files for the current page.
$language: (object) The language the site is being displayed in.
$language->langcode contains its textual representation.
$language->dir contains the language direction.
It will either be 'ltr' or 'rtl'.
$head_title: A modified version of the page title, for use in the TITLE
$head_title_array: (array) An associative array containing the string parts
that were used to generate the $head_title variable, already prepared to be
output as TITLE tag. The key/value pairs may contain one or more of the
following, depending on conditions:
title: The title of the current page, if any.
name: The name of the site.
slogan: The slogan of the site, if any, and if there is no title.
$head: Markup for the HEAD section (including meta tags, keyword tags, and
$styles: Style tags necessary to import all CSS files for the page.
for the page.
page. This variable should always be output first, before all other dynamic
$page: The rendered page content.
$page_bottom: Final closing markup from any modules that have altered the
page. This variable should always be output last, after all other dynamic
$classes Array of classes that can be used to style contextually through