openproject/app/assets/stylesheets/content/_hidden.sass

//-- copyright
// OpenProject is a project management system.
// Copyright (C) 2012-2018 the OpenProject Foundation (OPF)
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License version 3.
//
// OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
// Copyright (C) 2006-2017 Jean-Philippe Lang
// Copyright (C) 2010-2013 the ChiliProject Team
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// See docs/COPYRIGHT.rdoc for more details.
//++

// Overriding the browser's default [hidden] rule to force hiding the element as having a
// more specific rule (and almost everything will be more specific than [hidden]) will prevent using
// the hidden-attribute otherwise:
// "Note: Changing the value of the CSS display property on an element with the hidden attribute overrides the behavior.
// For instance, elements styled display: flex will be displayed despite the hidden attribute's presence."
// https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/hidden
[hidden]
  display: none !important


// Global -hidden class
.-hidden
  display: none