~function () {
  if (!document.querySelectorAll || !document.body)
    return;


  {
    var fGetColorScheme = function () {
      var tsColorScheme = null;

      try {
        if (window.localStorage) {
          var sColorScheme = localStorage.getItem('color_scheme') || null;

          if (sColorScheme != null) {
            tsColorScheme = +sColorScheme || 0;

            if (tsColorScheme > 0)
              tsColorScheme = 1;
            else if (tsColorScheme < 0)
              tsColorScheme = -1;
            else
              tsColorScheme = 0;
          }
        }
      } catch (_) { }

      return tsColorScheme;
    };

    var fSetColorScheme = function (tsColorScheme) {
      tsColorScheme = +tsColorScheme || 0;

      try {
        if (window.localStorage) {
          if (tsColorScheme)
            localStorage.setItem('color_scheme', tsColorScheme > 0 ? +1 : (tsColorScheme < 0 ? -1 : 0));
          else
            localStorage.removeItem('color_scheme');

          return true;
        }
      } catch (_) { }

      return false;
    };
  }



  {
    var bDarkMode = null;
    var fUpdateColorScheme = function () {
      var tsColorScheme = fGetColorScheme() || 0;


      {
        var bColorSchemeUser = !!tsColorScheme;
        var bColorSchemeDarkMode = tsColorScheme ? tsColorScheme > 0 : bDarkMode;

        document.body.setAttribute('data-color-scheme', (bColorSchemeUser ? 'user' : 'system') + '-' + (bColorSchemeDarkMode ? 'dark' : 'light'));
      }


      document.querySelectorAll('input[data-color-scheme]').forEach(function (oNode) {
        var tsColorSchemeNew = (oNode.getAttribute('data-color-scheme') || '').trim();
        tsColorSchemeNew = +tsColorSchemeNew || 0;

        if (tsColorSchemeNew > 0)
          tsColorSchemeNew = 1;
        else if (tsColorSchemeNew < 0)
          tsColorSchemeNew = -1;
        else
          tsColorSchemeNew = 0;

        oNode.checked = tsColorScheme == tsColorSchemeNew;
      });

      return true;
    };



    document.querySelectorAll('input[data-color-scheme]').forEach(function (oNode) {
      oNode.addEventListener('change', function (oEvent) {
        if (!oEvent || !oEvent.currentTarget)
          return;


        var tsColorScheme = (oEvent.currentTarget.getAttribute('data-color-scheme') || '').trim();
        tsColorScheme = +tsColorScheme || 0;

        if (!fSetColorScheme(tsColorScheme)) {
          oEvent.preventDefault && oEvent.preventDefault();
          return false;
        }

        fUpdateColorScheme();
      });
    });
  }


  {
    if (window.matchMedia) {
      var fSystemColorScheme = function (oMatchMedia) {
        bDarkMode = oMatchMedia && !!oMatchMedia.matches;
        fUpdateColorScheme();
      };

      var oMatchMedia = matchMedia('(prefers-color-scheme:dark)');

      if (oMatchMedia.addEventListener)
        oMatchMedia.addEventListener('change', fSystemColorScheme);
      else if (oMatchMedia.addListner)
        oMatchMedia.addListner('change', fSystemColorScheme);

      fSystemColorScheme(oMatchMedia);
    }

    else
      fUpdateColorScheme();
  }


}();