body {
  margin: 0;
}

div.content {
  font-family: tahoma, arial, sans-serif;
  padding: 3em 5em;
  padding-right: 4em;
  max-width: 850px;
  color: #222;
  line-height: 150%;
}

h1 {
  font-size: 200%;
  margin-left: -1em;
  margin-bottom: 1.4em;
  page-break-before: left;
}

h1 .number {
  display: block;
  font-size: 45%;
  font-weight: normal;
}

h2 {
  font-size: 150%;
}

div.block {
  padding: 0 .5em;
  position: relative;
}

div.exercisenum {
  top: 0;
  width: 7em;
  margin-left: -8em;
  position: absolute;
  text-align: right;
  z-index: 11;
  font-size: 85%;
  color: #AAAAAA;
}

div.exercise {
  border-left: .2em solid #FFBBBB;
  margin-left: -.7em;
  padding-left: .5em;
}

div.solution {
  border-left: .2em solid #AAEEAA;
  margin-left: -.7em;
  padding-left: .5em;
  position: relative;
}

div.solutionarrow {
  position: absolute;
  top: 0;
  margin-left: -4em;
  width: 3em;
  text-align: right;
  z-index: 11;
  color: #AAAAAA;
  cursor: pointer;
}

code {
  font-family: courier new, courier, monospace;
  color: #033;
}

p {
  margin: 1em 0;
  orphans: 2;
}

pre.preformatted, pre.code {
  margin: 1.1em 12px;
  border: 1px solid #CCCCCC;
  padding: .4em;
  font-family: courier new, courier, monospace;
  font-size: 90%;
  page-break-inside: avoid;
}

pre.invalid {
  border: 1px solid #FF9999;
}

a:link {
  color: #223388;
  text-decoration: none;
}

a:visited {
  color: #554477;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.footref, span.exponent {
  vertical-align: super;
  font-size: 60%;
}

span.footref {
  color: #223388;
  cursor: pointer;
}

ol.footnotes {
  font-size: 70%;
  padding-left: 2em;
}

div.footnotefloat {
  font-size: 80%;
}

div.footnotefloat code {
  color: #002222;
}

/* Revolting hack to make image-rulers work in IE */
hr {
  background: url(../img/hr.png) no-repeat top center;
  filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='img/hr.png');
  width: 1px;
  height: 1px;
  border: 0;
}
* > hr {
  width: 100%;
  height: 10px;
}

blockquote {
  font-style: italic;
  page-break-inside: avoid;
}

blockquote em {
  font-style: normal;
}

div.illustration {
  padding-left: 1em;
  page-break-inside: avoid;
}

div.picture {
  text-align: center;
  page-break-inside: avoid;
}

div.navigation {
  font-size: 85%;
  color: #AAAAAA;
  margin-top: 2em;
}

div.navigation a:link {
  color: #888888;
}

div.navigation a:visited {
  color: #888888;
}

ul.index {
  list-style-type: none;
  margin: 1em 0;
  padding: 0;
}

div.toggle {
  color: #AA0000;
  cursor: pointer;
}

div.toggle:hover {
  text-decoration: underline;
}

div.floater {
  position: absolute;
  border: 1px solid #888888;
  background-color: #EEEEEE;
  padding: .3em;
  z-index: 12;
}

button.react {
  position: absolute;
  z-index: 10;
  left: 3px;
  top: 3px;
  border: 0;
  height: 23px;
  width: 30px;
  padding: 0;
  background-image: url(../img/react.png);
  background-color: transparent;
  cursor: pointer;
}

div.reactpopup {
  position: absolute;
  font-family: tahoma, arial, sans-serif;
  padding: .2em .5em;
  border: 1px solid #888888;
  background-color: #EEEEEE;
  top: 27px;
  left: 3px;
  z-index: 12;
  overflow: auto; /* workaround for FF invisible-cursor bug */
}

div.reactpopup p {
  margin: .3em 0;
}

div.reactpopup span {
  width: 7.5em;
  display: block;
  float: left;
}
  
div.reactpopup input {
  border: 1px solid #888888;
  padding: 2px;
  vertical-align: middle;
  width: 12.5em;
}

div.reactpopup textarea {
  width: 24em;
  height: 10em;
  border: 1px solid #888888;
  padding: 2px;
  font-family: tahoma, arial, sans-serif;
}

div.reactpopup button {
  border: 1px solid #888888;
  background-color: white;
}

div.footer {
  font-size: 80%;
  color: #AAAAAA;
  margin-top: 2em;
}

div.footer a:link, div.footer a:visited {
  color: #6688BB;
}

a.donate {
  position: absolute;
  font-family: tahoma, arial, sans-serif;
  z-index: 12;
  left: 6px;
  top: 33px;
  text-decoration: none;
  color: #CCCCCC;
  font-size: 70%;
  font-weight: bold;
}

a.paragraph {
  position: absolute;
  color: white;
  color: transparent;
  display: block;
  right: 0px;
  padding: 0 1em;
  margin-right: -2em;
  text-decoration: none;
}

p:hover a.paragraph, a.paragraph:hover { color: #aaa; }

.banner {
    background: #ffa;
    margin: 1em 4em 1em 0;
    padding: .5em 1em;
    border: 1px solid #eea;
}