body       { margin: 1% 9% 5% 9%;/* top right bottom left */
             line-height: 2em;
	     /*font-family: Verdana, Arial, Helvetica, sans-serif, times, Heiti TC, PMingLiU, PMingLiu-ExtB, SimSun, SimSun-ExtB, HanaMinA, HanaMinB, 'Noto Sans CJK SC';
             font-family: 'Helvetica Neue', 'Hiragino Sans GB', 'Microsoft YaHei', '微软雅黑', SimSun, '宋体', 'Microsoft JhengHei', '微軟正黑體', PMingLiU, '新細明體', Helvetica, Arial, sans-serif;
             */font-size: x-large }
nav        { display: flex;
             justify-content: space-between }
h1         { text-align: center;
             margin-top: 2em }
h2         { margin-top: 2em }
ul         { list-style-type: none;
             margin-left: 35% }
ol, dd     { margin-bottom: 1em }
ol.toc     { margin-left: 3em }
li         { margin-top: .25em }
hr         { margin-top: 2em }
img        { display: block;
             margin: auto }
a          { text-decoration: none }
p          { text-indent: 2em }
aside      { font-size: 75% }
aside,
blockquote { margin: 2em 4em 2em 4em }
blockquote { font-family: 'AR PL UKai CN', 'Microsoft Kai' }
a:hover    { color: gold;
             font-weight: bold }
span, e    { text-indent: 0;
             position: absolute;
	     max-width: 980px;
             background: #fff;
             font-size: large;
             line-height: 1.5em;
	     padding: 9px;
             border: 1px solid rgba(0,0,0,0.1);
             border-radius: 3px;
             box-shadow: 0 15px 45px -15px rgba(0,0,0,0.3);
	     display: none;
             z-index: 9 }
sup:hover+span
, c:hover+e{ display: initial }
h3, figcaption,
.c         { text-align: center;
             margin-right: 5em;
	     margin-left: 5em }
.p         { margin-left: 40%;
             color: gray }
.r         { margin: 3em 2em 6em 0;
             text-align: right }