base.css

body {
    background: #FFFFE0;
    background: lemon;
    padding: .1em 4em 1em 4em;
    color: black; 
    max-height: 100%;
    font-family: Georgia , "Times New Roman", serif;
    font-size: 1em;
    line-height: 150% ;
}

a { font-style: italic ; font-weight: normal; text-decoration: none ; }

a:link    { color: blue; }
a:visited { color: rgb(106,90,205); }
a:hover   { color: blue;  text-decoration: underline }
a:active  { color: blue; }

h1, h2, h2 a, h3, h3 a, h4, h4 a, h5, h5 a { 
    font-family: "Trebuchet MS", Helvetica, sans-serif;
    font-style: normal;
}

h1 { font-size: 2em ;  line-height: 150% ;
     margin-top: 1em ; margin-bottom: 1em ; 
     text-align: center;
}

h2 {
    font-size: 1.5em ;
    margin-top: 2em ; text-align: center;
}

h3 {
    font-size: 1.2em ;
    margin-top: 1em ;
}

h4 {
    font-size: 1.1em ;
     margin-top: 2em ; margin-bottom: 0em ; 
     text-align: center;
}

h5 {
    font-size: .8em ; font-weight: normal;
}

h6 {
    font-size: .8em ; font-weight: normal;
}

.centered {
    margin-left: auto;
    margin-right: auto;
}

.right {
   float: right
}

code {
 font-size: 1.2em ;
}

pre {
 font-size: 1.2em ;
 line-height: 120% ;
 white-space: pre-wrap;
 white-space: -moz-pre-wrap;
 white-space: -o-pre-wrap;
 background: #faf8f0;
 display: block;
 padding: 0.5em 1em;
 border: 1px solid #bebab0;
}

.prob {
 display: block;
 padding: 0.5em 1em;
 border: 1px solid #bebab0;
 background: #ffe0e0;
 background: navajowhite;
}

.contents {
 display: block;
 padding: 0.5em 1em;
 border: 1px solid #bebab0;
 background: #faf8f0;
}

.box {
 display: block;
 padding: 0.5em 1em;
 border: 1px solid #bebab0;
 background: lemonchiffon;
}

p.centered {
  text-align: center;
}