html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background: #424242;
  font-size: 16px;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  font-size: .875rem;
}

.form {
  margin: 5rem 0;
  width: 30rem;
  background: #FAFAFA;
  padding: 2rem;
  border-radius: .25rem;
  box-shadow: 0 4px 5px  hsla(0, 0%, 0%, .5);
}

.form-group {
  display: flex;
  flex-flow: column nowrap;
}

.form-group:not(:first-child) {
  margin-top: 1rem;
}

.color-display {
  display: flex;
  align-items: center;
}

.color-group {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.color-group > .color-code {
  flex: 1 0 auto;
  margin-left: 1rem;
}

.color-hue {
  height: 2rem;
  align-self: stretch;
  background-image: linear-gradient(to right, red, yellow, lime, cyan, blue, magenta, red)
}

.form-input {
  width: 100%;
  margin: 0;
}

.color-preview {
  height: 5rem;
  width: 5rem;
  background-color: lightgrey;
  border: 1px solid black;
  display: flex;
  justify-content: center;
  align-items: center;
}

.color-text {
  font-size: 3rem;
}