style.css

form {
  margin-top: 4em;
}

.container {
  margin-bottom: 2em;
  max-width: 800px;
  font-size: 18px;
}

.container:first-child {
  margin-bottom: 1em;
}

.label {
  float: left;
  margin-right: 2em;
  padding: 1em 0;
  vertical-align: center;
}

.helptext {
  clear: both;
}

.helptext p {
  line-height: 2;
}

code {
  margin: 1em 0;
  padding: 1em 2em;
  display: block;
}

.input-group {
  float: right;
  width: 50%;
}

.input-group input {
  padding: 1em;
}

.input-group input[type='number'],
.input-group input[type='text'],
.input-group textarea,
.input-group select {
  width: 100%;
}

.input-group input[type='checkbox'] {
  margin: 1.34em;
  margin-right: 0;
  float: right;
}

.input-group select {
  margin: 0.9em;
  margin-right: 0;
  float: right;
}

/* 
* For Flexbox Support
*/

.container > label {
  display: -webkit-box;
  display: -moz-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
  justify-content: space-between;
}

.container .input-group {
  width: initial;
  flex: 1 1 auto;
}

/* Shortcode Example page */
.flex,
.examples {
  display: -webkit-box;
  display: -moz-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
  flex-flow: row wrap;
  justify-content: space-around;
}
.flex > label {
  flex: 0 1 200px;
}
.flex > input {
  flex: 1 1 400px;
}
.examples .list-item {
  flex: 1 1 250px;
}
p {
  vertical-align: top;
  word-wrap: break-word;
}
.list-item {
  width: 250px;
  display: inline-block;
  vertical-align: top;
  padding: 15px;
}
.list-item p {
  font-size: 1.2em;
}