.hidden {
  display: none;
}

.success {
  background-color: #ccffcc;
}

.regex {
  background-color: #eeeeee;
  padding-right: 0.3em;
  padding-left: 0.3em;
  padding-bottom: 0.1em;
  padding-top: 0.1em;
  border-radius: 0.1em;
  border-width: 1px;
  border-color: #bbbbbb;
  border-style: solid;
}

.key {
  background-color: #eeeeee;
  display: inline-block;
  padding: 3px 5px;
  font: 11px "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
  line-height: 10px;
  color: #444d56;
  vertical-align: middle;
  border: solid 1px #c6cbd1;
  border-color: #bbbbbb;
  border-radius: 3px;
  box-shadow: inset 0 -1px 0 #959da5;
}

p {
  line-height: 140%;
}

header {
  background-color: #eeeeee;
  right: 0px;
  left: 0px;
  top: 0px;
  width: 100%;
  border: 0px;
}

header h2 {
  padding-right: 1em;
  padding-left: 1em;
  margin-top: 0.3em;
  margin-bottom: 0.5em;
  text-align: center;
}

body {
  display: flex;
  min-height: 100vh;
  flex-direction: column;
  margin: 0px;
  background-color: white;
}

.main {
  padding-right: 1em;
  padding-left: 1em;
  flex: 1;
}
@media (min-width: 40em) {
  .main {
    max-width: 40em;
    margin-left: calc(50% - 20em);
  }
}
footer {
  padding: 1em;
  margin-top: 1em;
  background-color: #eeeeee;
  text-align: center;
}

footer img {
  vertical-align: middle;
}

footer .links {
  padding-bottom: 0.5em;
}
footer .links a {
  margin-left: 1em;
  margin-right: 1em;
  white-space: nowrap;
}

footer a {
  color: black;
}

.next-page {
  text-align: center;
  display: block;
  margin: 1em;
  padding: 1em;
  background-color: #eeeeee;
  border-radius: 1em;
  text-decoration: none;
  color: black;
}

.requirements-satisfied .next-page {
  background-color: #ccffcc;
}

img {
  max-width: 100%;
}