a:link, a:visited, a:hover, a:active {
  color: #eee;
}

footer a:link, footer a:visited, footer a:hover, footer a:active {
  color: #00adb5;
}

body {
  font-family: Verdana, sans-serif;
  color: #eee;
  background-color: #222831;
  padding: 2em;
  display: flex;
  flex-direction: column;
}

h1, h2 {
  text-align: center;
}

hr {
  width: 90%;
  border-color: #00adb5;
}

a {
  text-decoration: none;
}

.challenge-container {
  display: flex;
  align-self: center;
  width: 90%;
}

::-webkit-input-placeholder {
  color: #808998;
}

:-moz-placeholder {
  color: #808998;
}

::-moz-placeholder {
  color: #808998;
}

:-ms-input-placeholder {
  color: #808998;
}

.input-length {
  margin-right: 0.5em;
}

.output-length {
  margin-left: 0.5em;
}

.input-length, .output-length {
  width: 90%;
  display: flex;
  flex-direction: column;
  align-self: center;
}

.input-value {
  color: #eee;
  background-color: #222831;
  border: none;
  text-align: center;
  width: 98%;
}

:focus {
  outline: none;
  background: #37414f;
}

.value, .result {
  margin-top: 1em;
  margin-bottom: 1em;
  border: 1px solid #00adb5;
  font-size: 2em;
  height: 2.4em;
  padding-top: 1em;
  text-align: center;
}

input[type=radio] {
  display: none;
}
input[type=radio]:checked + label {
  color: #eee;
}

label {
  color: #67707e;
  padding: 0.4em;
  margin: 10em 0.2em 1em 0.2em;
}

table {
  width: 90%;
  height: 120px;
  text-align: center;
  align-self: center;
  margin-left: auto;
  margin-right: auto;
}

footer {
  font-size: 0.8em;
  color: #00adb5;
  text-align: center;
  margin-top: 10em;
}

@media (max-width: 850px) {
  table {
    letter-spacing: -1px;
  }
}
@media (max-width: 740px) {
  body {
    padding: 0 1em 0 1em;
  }

  h1 {
    font-size: 1.4em;
  }

  h2 {
    font-size: 1.2em;
  }

  .challenge-container {
    display: flex;
    flex-direction: column;
  }

  .input-length {
    margin-right: 0em;
  }

  .output-length {
    margin-left: 0em;
  }

  .value, .result {
    margin-top: 0.4em;
    margin-bottom: 0.4em;
    font-size: 1.4em;
    height: 1.8em;
    padding-top: 0.4em;
  }

  form, table, tr, td {
    margin: 0;
  }

  label {
    font-size: 0.8em;
  }
}

.article {
  padding:0 15%;
}

.article a {
  color:yellow;
}