sample_app.css

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  background: #f2f5f6;
  font: 87.5%/1.5 "Open Sans", sans-serif;
  min-height: 100vh;
  display: flex;
  flex-grow: 1;
  margin: 0;
}

a:link:not(.button),
a:visited:not(.button) {
  text-decoration: none;
  color: #008200;
}

a:hover:not(.button) {
  color: #006800;
}

a:active:not(.button) {
  color: #004500;
}

.guide {
  background: #fff;
  max-width: 432px;
  min-width: 320px;
  overflow: auto;
  height: 100vh;
  padding: 40px;
  flex: 1 432px;
}

.guide:target {
  display: block;
}

.guide::before {
  background: url(sage-developers.png) no-repeat 50% 0 / contain;
  padding: 0 0 calc((479 / 864) * (100% + 80px));
  margin: 0 -40px 40px;
  display: block;
  content: "";
}

.title {
  color: rgba(0, 0, 0, 0.9);
  font-weight: bold;
  line-height: 30px;
  margin: 0 0 24px;
  font-size: 24px;
}

.steps {
  padding: 0;
  margin: 0;
}

.step {
  counter-increment: item;
  list-style: none inside;
  margin-bottom: 10px;
  padding-left: 32px;
  position: relative;
  margin: 20px 0 0;
}

.step__title {
  font-size: inherit;
  font-weight: 600;
  margin: 0 0 4px;
}

.step__body {
  color: rgba(0, 0, 0, 0.55);
}

.step::before {
  content: " " counter(item) " ";
  border: 1px solid #99adb6;
  justify-content: center;
  display: inline-flex;
  align-items: center;
  text-align: center;
  position: absolute;
  border-radius: 50%;
  font-weight: bold;
  font-size: 13px;
  height: 24px;
  width: 24px;
  left: 0;
  top: 0;
}

.main {
  padding: 0 20px;
  flex-wrap: wrap;
  overflow: auto;
  height: 100vh;
  display: flex;
  flex: 999;
}

.request {
  padding: 40px 20px;
  min-width: 432px;
  flex: 1 50%;
}

.response {
  padding: 40px 20px;
  min-width: 432px;
  flex: 999 432px;
}

.field:not(:last-child) {
  margin-bottom: 24px;
}

.field__label {
  margin-bottom: 8px;
  line-height: 21px;
  font-weight: 600;
  display: block;
}

.field__help {
  color: rgba(0, 0, 0, 0.55);
  margin-bottom: 4px;
  position: relative;
  top: -8px;
}

.field__help.is-error {
  color: #C7384F;
}

.field__body {
  display: flex;
}

.field__input {
  text-overflow: ellipsis;
  line-height: inherit;
  position: relative;
  overflow: hidden;
  font: inherit;
  flex: 1 1;

  border: 1px solid #668592;
  -webkit-appearance: none;
  -moz-appearance: none;
  background: #fff;
  appearance: none;
  border-radius: 0;
  resize: vertical;
  font-size: 16px;
  padding: 8px;
  height: 40px;
}

/* .field__input:read-only:not(select) {
  background: rgba(255, 255, 255, 0.5);
  border-color: rgba(0, 0, 0, 0.15);
} */

.field__input:disabled {
  border-color: rgba(0, 0, 0, 0.15);
  color: rgba(0,0,0,.55);
  background: transparent;
  cursor: not-allowed;
}

.field__input.is-invalid {
  border: 2px solid #C7384F;
}

.field__input:focus:not(:disabled),
.button:focus:not(:disabled) {
  outline: 3px solid #ffb500;
  outline-offset: 0;
  z-index: 1;
}

.button {
  text-decoration: none;
  background: #008200;
  display: inline-block;
  white-space: nowrap;
  position: relative;
  font-weight: bold;
  line-height:40px;
  cursor: pointer;
  font-size: 16px;
  padding: 0 24px;
  color: #fff;
  height: 40px;
  border: 0;
  margin: 0;
}

.button:hover {
  background: #006800;
}

.button:active {
  background: #004500;
}
.button:disabled {
  background-color: #e6ebed;
  color: rgba(0,0,0,.3);
  cursor: not-allowed;
}

.button.is-destructive {
  background: #c7384f;
}

.button.is-centered {
  margin: auto;
}

.form__button {
  margin-top: 48px;
}

.response__body {
  font-family: monospace;
  font-size: 14px;
  white-space: pre;
  overflow: auto;
  height: calc(100vh - 234px);
}

code {
  border: 1px solid rgba(0, 0, 0, 0.15);
  color: rgba(0, 0, 0, 0.95);
  font-family: monospace;
  background: #f4f4f4;
  border-radius: 4px;
  padding: 2px 4px;
  font-size: 12px;
}

/* https://github.com/h5bp/html5-boilerplate/blob/5f00e406721bac39dcd7b87ca185ad02b2dcb1c4/dist/css/main.css#L122 */
.sr-only {
  border: 0;
  clip: rect(0, 0, 0, 0);
  height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  white-space: nowrap;
  width: 1px;
  /* 1 */
}

.products {
  list-style: none;
  padding: 0;
  margin: 0;
}

.product {
  line-height: 24px;
  height: 24px;
  margin: 0;
}

.flag::before {
  vertical-align: middle;
  font-size: 24px;
}

.flag--ca::before {
  content: "🇨🇦 ";
}

.flag--de::before {
  content: "🇩🇪 ";
}

.flag--es::before {
  content: "🇪🇦 ";
}

.flag--fr::before {
  content: "🇫🇷 ";
}

.flag--gb::before {
  content: "🇬🇧 ";
}

.flag--ie::before {
  content: "🇮🇪 ";
}

.flag--us::before {
  content: "🇺🇸 ";
}