function calcFontSize(count) {
    return count / 6 + 12;
}
var tags = new Array();
var now = (new Date()).getTime();
var tagsNode = document.getElementById('tags');
var childNodes = tagsNode.childNodes;
for (var i = 0; i < childNodes.length; i++) {
  var e = childNodes.item(i);
  if (e.nodeName.match(/li/i)) {
    var s = e.title.split(':');
    e.style.fontSize = calcFontSize(s[1]) + 'px';
    var d = s[2].split('-');
    var diff = (now - (new Date(d[0], d[1] - 1, d[2])).getTime()) / 86400000;

// 変更前の更新頻度
//  if (diff < 14) e.className = 'hot';
//  else if (diff > 365) e.className = 'oldest';
//  else if (diff > 60) e.className = 'old';

// 変更後の更新頻度
    if (diff < 15) e.className = 'level1';      //      ～ 15日
    else if (diff <  30) e.className = 'level2';//  15日～ 30日
    else if (diff <  60) e.className = 'level3';//  30日～ 60日
    else if (diff <  90) e.className = 'level4';//  60日～ 90日
    else if (diff < 180) e.className = 'level5';//  90日～180日
    else if (diff < 365) e.className = 'level6';// 180日～365日

    tags.push([ e, s[1] ]);
  }
}
tagsNode.style.display = 'block';
 
var coff = 0;
var coffNode = document.getElementById('coff');
function decCoff(c) {
  if (coff == 0) return;
  coff -= c;
  if (coff < 0) coff = 0;
  coffNode.innerHTML = coff;
  refreshCoff();
}
function incCoff(c) {
  if (coff == 20) return;
  coff += c;
  if (coff > 20) coff = 20;
  coffNode.innerHTML = coff;
  refreshCoff();
}
function refreshCoff() {
  for (var i = 0; i < tags.length; i++) {
    var tag = tags[i];
    tag[0].style.visibility = (tag[1] <= coff) ? "hidden" : "visible";
  }
}