* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: #050807;
  color: #fff;
  font: 13px sans-serif;
}

body {
  overflow-x: hidden;
}

.page {
  min-height: 100vh;
  padding: 12px;
}

.topbar,
.rulePanel {
  padding: 8px;
  background: rgba(20, 20, 20, 0.88);
  border-radius: 8px;
  backdrop-filter: blur(4px);
}

.topbar {
  position: relative;
}

.backLink {
  display: inline-block;
  margin-bottom: 6px;
  color: #aaa;
  text-decoration: none;
}

.backLink:hover {
  color: #fff;
}

h1 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 600;
}

.toolbar,
.ruleBits {
  display: flex;
  align-items: end;
  gap: 8px;
  flex-wrap: wrap;
}

.field,
.switchField {
  display: flex;
  align-items: center;
  gap: 5px;
  color: #fff;
  white-space: nowrap;
}

.field {
  flex-direction: column;
  align-items: flex-start;
}

input,
select,
button {
  min-height: 30px;
  padding: 5px 8px;
  background: #222;
  color: #eee;
  border: 1px solid #444;
  border-radius: 4px;
  font: inherit;
}

input[type="number"] {
  width: 86px;
}

button {
  cursor: pointer;
}

button:hover,
select:hover,
input:hover {
  background: #333;
}

.rulePanel {
  position: relative;
  margin-top: 8px;
  overflow-x: auto;
}

.ruleBits {
  flex-wrap: nowrap;
  min-width: 520px;
}

.ruleBit {
  display: flex;
  min-width: 54px;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  color: #fff;
}

.patternLabel {
  display: flex;
  gap: 2px;
}

.bit {
  width: 9px;
  height: 9px;
  border: 1px solid #777;
}

.bit-1 {
  background: #00ff66;
}

.bit-0 {
  background: #111;
}

.ruleBit input {
  width: 18px;
  min-height: 18px;
  accent-color: #00ff66;
}

.ruleBit output {
  color: #aaa;
  line-height: 1;
}

.ruleHint {
  margin: 6px 0 0;
  color: #888;
  font-size: 11px;
}

.boardViewport {
  width: 100%;
  margin-top: 8px;
  overflow-x: auto;
}

#board {
  display: block;
  margin: 0 auto;
  background: #050807;
  image-rendering: pixelated;
}

@media (max-width: 760px) {
  .toolbar {
    align-items: stretch;
  }

  .field,
  .switchField,
  button {
    flex: 1 1 auto;
  }
}