:root {
  --bg: #111418;
  --fg: #e6e8eb;
  --muted: #9098a4;
  --accent: #ffb84d;
  --pill-bg: #1d2126;
  --pill-border: #2c323a;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
  padding: 24px 16px 48px;
  gap: 16px;
}

header {
  max-width: 880px;
  text-align: center;
}

h1 {
  margin: 0 0 4px;
  font-size: 22px;
  font-weight: 600;
  letter-spacing: 0.2px;
}

.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

.subtitle a {
  color: var(--accent);
  text-decoration: none;
}

.subtitle a:hover {
  text-decoration: underline;
}

.paper-credit {
  display: block;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  width: 100%;
}

#status {
  display: inline-block;
  padding: 6px 14px;
  background: var(--pill-bg);
  border: 1px solid var(--pill-border);
  border-radius: 999px;
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

#maze {
  display: block;
  width: min(100%, 900px);
  height: auto;
  aspect-ratio: 1200 / 900;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.5);
  cursor: crosshair;
  image-rendering: pixelated;
}

#controls {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
}

#controls label,
#alignment-control {
  display: flex;
  align-items: center;
  gap: 10px;
  font-variant-numeric: tabular-nums;
}

/* Engine selector + status share one horizontal row above the maze. */
#top-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

#engine-fieldset {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  border: 0;
}

.radio-pill {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 10px;
  background: var(--pill-bg);
  border: 1px solid var(--pill-border);
  border-radius: 999px;
  cursor: pointer;
  user-select: none;
}

.radio-pill input {
  margin: 0;
  accent-color: var(--accent);
  cursor: pointer;
}

.radio-pill span {
  font-weight: 600;
  color: var(--fg);
  letter-spacing: 0.3px;
}

#batch-slider,
#steps-slider {
  width: 220px;
  accent-color: var(--accent);
  cursor: pointer;
}

#alignment-select {
  cursor: pointer;
}

#batch-value,
#steps-value {
  display: inline-block;
  min-width: 24px;
  font-weight: 600;
  color: var(--fg);
  text-align: right;
}

/* DDIM-steps slider only matters for DP. The active engine is reflected on
   the #controls container via app.js -- when ACT is selected, hide it. */
#controls[data-engine="act"] #steps-control {
  display: none;
}

#batch-hint {
  max-width: 760px;
  font-size: 11px;
  opacity: 0.75;
  text-align: center;
  line-height: 1.5;
}

#batch-hint strong {
  color: var(--fg);
  opacity: 0.95;
  font-weight: 600;
}