body {
  background-color: #DDD;
}

main {
  max-width: 600px;
  padding: 9px;
  margin: 15px auto;
  border: 2px solid black;
  background-color: white;
}

p {font-size: 125%;}


.parren-space {
  display: inline-block;
}
.paren-internal {
  display: inline-block;
  width: 90px;
  font-family: Courier, Courier New, fixed;
  font-size: 16px;
  text-align: center;
}
.placeholder {
  display: inline;
  color: gray;
  max-height: 1em;
}
.hidden-content {
  display: none;
  max-height: 1em;
}

a {
  color: blue;
  text-decoration: none;
  font-weight: bold;
}

a:link {
  color: blue;
  text-decoration: none;
  font-weight: bold;
}