html, body {
  position: relative;
  width: 100%;
  height: 100%;
  font-size: 16px;
  background-color: #222;
}

* {
  box-sizing: border-box;
  color: #ddd;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
  font-size: 1rem;
  user-select: none;
}

body {
  margin: 0;
  padding: 1rem;
}

.main {
  display: flex;
  flex-flow: column nowrap;
  align-items: stretch;
  justify-content: flex-start;
}

.header {
  font-size: 2rem;
  font-weight: 500;
}

.row, .row-2 {
  margin: 0 0 0.5rem 0;
  display: flex;
  flex-flow: row nowrap;
  align-items: flex-start;
  justify-content: stretch;
}

.row .label {
  flex: 1 1 0;
}

.row .input {
  flex: 2 2 0;
}

input, select {
  width: 100%;
  background-color: #444;
  color: #ddd;
  border: none;
}

button {
  font-size: 1rem;
  margin: 0.25rem;
  padding: 0.5rem;
  border-radius: 0.25rem;
  border: none;
  background-color: #444;
}

button:hover {
  background: #555;
}

button:active {
  background: #777;
}

.preview {
  width: 100%;
  display: flex;
  flex-flow: column nowrap;
  align-items: stretch;
  justify-content: flex-start;
}

.ground {
  position: relative;
  height: 3rem;
}

.ground-btn, .ground-led {
  height: 3rem;
  position:absolute;
  top: 0;
  left: 0;
  width: 100%;
  display: flex;
  flex-flow: column nowrap;
  align-items: stretch;
  justify-content: flex-start;
}

.ground-row {
  flex: 1;
  width: 100%;
  display: flex;
  flex-flow: row nowrap;
  align-items: stretch;
  justify-content: space-between;
}

.ground-btn > .ground-row > div {
  text-align: center;
  flex: 1 0 0;
}

.ground-led-0 {
  flex: 1 0 0;
}

.ground-led-1 {
  flex: 0.4rem 0 0;
}

.ground-led-2 {
  flex: 0.2rem 0 0;
}

.ground-btn {
  background-color: #0008;
}

.ground-data {
  padding: 0.1rem 0;
  font-size: 0.8rem;
}