anchor.diff:      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
       <meta charset="utf-8">
       <style>
  -      #detail {
  -        position: fixed;
  -        right: 0;
  -        top: 0;
  -        bottom: 0;
  -        background-color: black;
  -        color: white;
  -        transition: all 0.5s ease;
  -        overflow-y: scroll;
  +      body {
  +        text-align: left;
  +        font-size: .8rem;
  +        font-family: Consolas;
         }
   
  -      #detail ul {
  -        padding: 1rem 2rem 1rem 1rem;
  +      td, th {
  +          vertical-align: top;
  +          border-top-style: dashed;
  +          border-right-style: dashed;
  +          border-width: 1px;
  +          padding: .4rem;
         }
   
  -      #detail li {
  -        list-style: none;
  +      tr td:nth-child(1), tr th:nth-child(1) {
  +          border-left-style: dashed;
  +          border-width: 1px;
         }
   
  -      .hidden {
  -        visibility: hidden;
  -        opacity: 0;
  +      tr:last-child td {
  +          border-bottom-style: dashed;
  +          border-width: 1px;
         }
   
  -      .chosen {
  -        background-color: cyan;
  +      ul {
  +          margin: 0;
  +          padding: 0;
  +          height: 1rem;
  +          overflow-y: hidden;
  +      }
  +
  +      li {
  +          list-style: none;
  +      }
  +
  +      input {
  +        display: none;
  +      }
  +
  +      label {
  +        float: left;
  +        margin-right: .5rem;
  +      }
  +
  +      label:after {
  +        content: "+";
  +      }
  +
  +      input:checked ~ ul {
  +        height: 100%;
  +      }
  +
  +      input:checked ~ label:after {
  +        content: "-";
         }
       </style>
     </head>
     <body>
       <div id='table'></div>
  -    <div id='detail'><div>
       <script>
         var data = <%= json %>;
   
  
positive.code:           return ul.join('');
          }
  
          var tbody = document.querySelector('#table tbody')
  
          tbody.addEventListener('click', function(ev){
            next_choise();
            var tr = tr_of(ev.target);
            tr.setAttribute('class', 'chosen');
            var detail = document.getElementById('detail');
            detail.setAttribute('class', 'hidden');
            detail.innerHTML = make_ul(data[tr.id].stack);
            setTimeout(function(){
              detail.setAttribute('class', null);
            }, 500);
          });
        })();
      </script>
    </body>
  
negative.code: 
        // table
        (function(){
  
          function ul(arr){
            var ul = ['<ul>'];
            arr.forEach(function(r){
              ul.push_mass('<li>', r, '</li>');
  