// css.js

function get_css(rule_name, stylesheet, delete_flag) {
  if (!document.styleSheets)return false;
  rule_name = rule_name.toLowerCase();
  stylesheet = stylesheet || 0;
  for (var i = stylesheet; i < document.styleSheets.length; i++) {
    var styleSheet = document.styleSheets[i];
    css_rules = document.styleSheets[i].cssRules || document.styleSheets[i].rules;
    if (!css_rules)continue;
    var j = 0;
    do{
      if (css_rules.length && j > css_rules.length + 5)return false;
      if (css_rules[j].selectorText && css_rules[j].selectorText.toLowerCase() == rule_name) {
        if (delete_flag == true) {
          if (document.styleSheets[i].removeRule)document.styleSheets[i].removeRule(j);
          if (document.styleSheets[i].deleteRule)document.styleSheets[i].deleteRule(j);
          return true
        } else return css_rules[j]
      }
    } while (css_rules[++j])
  }
  return false;
}

function add_css(rule_name, stylesheet) {
  rule_name = rule_name.toLowerCase();
  stylesheet = stylesheet || 0;
  if (!document.styleSheets || get_css(rule_name, stylesheet))return false;
  (document.styleSheets[stylesheet].insertRule) ? document.styleSheets[stylesheet].insertRule(rule_name + ' { }', 0) : document.styleSheets[stylesheet].addRule(rule_name, null, 0);
  return get_css(rule_name, stylesheet)
}

function get_sheet_num(href_name) {
  if (!document.styleSheets)return false;
  for (var i = 0; i < document.styleSheets.length; i++) {
    if (document.styleSheets[i].href && document.styleSheets[i].href.toString().match(href_name))return i
  }
  return false;
}

function remove_css(rule_name, stylesheet) {
  return get_css(rule_name, stylesheet, true)
}

function add_sheet(url, media) {
  if (document.createStyleSheet) {
    document.createStyleSheet(url)
  } else {
    var newSS = document.createElement('link');
    newSS.rel = 'stylesheet';
    newSS.type = 'text/css';
    newSS.media = media || "all";
    newSS.href = url;
    document.getElementsByTagName("head")[0].appendChild(newSS)
  }
}