catstodon/app/views/layouts/mailer.html.haml

!!!
%html{ lang: I18n.locale }
  %head
    %meta{ 'http-equiv' => 'Content-Type', 'content' => 'text/html; charset=utf-8' }/
    %meta{ name: 'viewport', content: 'width=device-width, initial-scale=1.0, shrink-to-fit=no' }

    = stylesheet_pack_tag 'mailer'
  %body{ dir: locale_direction }
    %table.email-table{ cellspacing: 0, cellpadding: 0 }
      %tbody
        %tr
          %td.email-body.email-start
            .email-container
              %table.content-section{ cellspacing: 0, cellpadding: 0 }
                %tbody
                  %tr
                    %td.content-cell.header
                      .email-row
                        .col-6
                          %table.column{ cellspacing: 0, cellpadding: 0 }
                            %tbody
                              %tr
                                %td.column-cell
                                  = link_to root_url do
                                    = image_tag full_pack_url('media/images/mailer/wordmark.png'), alt: 'Mastodon', height: 34, class: 'logo'

    = yield

    %table.email-table{ cellspacing: 0, cellpadding: 0 }
      %tbody
        %tr
          %td.email-body.email-end
            .email-container
              %table.content-section{ cellspacing: 0, cellpadding: 0 }
                %tbody
                  %tr
                    %td.content-cell.content-end
                      != '  '
                  %tr
                    %td.blank-cell.footer
                      .email-row
                        .col-6
                          %table.column{ cellspacing: 0, cellpadding: 0 }
                            %tbody
                              %td.column-cell
                                %p= t 'about.hosted_on', domain: site_hostname
                                %p
                                  = link_to t('application_mailer.notification_preferences'), settings_preferences_notifications_url
                                  - if defined?(@type)
                                    ·
                                    = link_to t('application_mailer.unsubscribe'), unsubscribe_url(token: @user.to_sgid(for: 'unsubscribe').to_s, type: @type)
                              %td.column-cell.text-right
                                = link_to root_url do
                                  = image_tag full_pack_url('media/images/mailer/logo.png'), alt: 'Mastodon', height: 24