app/views/layouts/application.html.erb
<!DOCTYPE html>
<html>
<head>
<% html_title = content_for?(:html_title) ? yield(:html_title) : nil %>
<title><%= [html_title, 'OandaApiRails'].compact.join(' - ') %></title>
<%= csrf_meta_tags %>
<%= csp_meta_tag %>
<meta name="viewport" content="width=device-width, initial-scale=1">
<%= javascript_importmap_tags %>
<%= stylesheet_link_tag 'application', media: 'all', 'data-turbo-track': 'reload' %>
<%= render partial: 'partials/stylesheets' %>
<%= favicon_link_tag 'favicon.ico' %>
</head>
<%= tag.body class: [dark_mode: cookies['dark_mode'] == 'isActive'], data: {locale: I18n.locale} do %>
<%= render partial: 'partials/menu' %>
<div class="container">
<%= render_notices %>
<%= yield %>
</div>
<button class="dark-mode-toggle">🌓</button>
<% end %>
</html>