:root {
  --bg: #0f1419;
  --surface: #1a2332;
  --surface2: #243044;
  --border: #334155;
  --text: #e8edf4;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --accent-hover: #7dd3fc;
  --success: #4ade80;
  --warn: #fbbf24;
  --radius: 10px;
  --font: "Segoe UI", system-ui, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

header {
  padding: 1.5rem 1.5rem 1rem;
  text-align: center;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #1e293b 0%, var(--bg) 100%);
}

header h1 {
  margin: 0 0 0.4rem;
  font-size: 1.6rem;
  font-weight: 600;
}

.tagline {
  margin: 0 auto;
  max-width: 40rem;
  color: var(--muted);
  font-size: 0.9rem;
}

main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.25rem 1.5rem 2rem;
}

.steps-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.steps {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.steps-action {
  margin-left: auto;
  flex-shrink: 0;
}

.step {
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  font-size: 0.8rem;
  color: var(--muted);
  background: var(--surface);
  border: 1px solid var(--border);
}

.step.active {
  color: #0f172a;
  background: var(--accent);
  border-color: var(--accent);
  font-weight: 600;
}

.step.done {
  color: var(--success);
  border-color: rgba(74, 222, 128, 0.4);
}

.status-bar {
  margin: 0 0 1rem;
  padding: 0.65rem 1rem;
  border-radius: 8px;
  font-size: 0.9rem;
}

.status-info {
  background: rgba(56, 189, 248, 0.12);
  border: 1px solid rgba(56, 189, 248, 0.35);
  color: var(--accent-hover);
}

.status-success {
  background: rgba(74, 222, 128, 0.12);
  border: 1px solid rgba(74, 222, 128, 0.35);
  color: var(--success);
}

.status-error {
  background: rgba(248, 113, 113, 0.12);
  border: 1px solid rgba(248, 113, 113, 0.4);
  color: #fca5a5;
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

.panel h2 {
  margin: 0 0 0.5rem;
  font-size: 1.15rem;
}

.panel-desc {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0 0 1rem;
}

.drop-zone {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 180px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}

.drop-zone.has-file { border-color: var(--success); border-style: solid; }

.file-input-overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.file-name { font-size: 0.85rem; color: var(--success); font-weight: 500; }

.drop-zone:hover,
.drop-zone.dragover {
  border-color: var(--accent);
  background: rgba(56, 189, 248, 0.06);
}

.drop-icon { font-size: 2rem; }
.drop-text { font-weight: 500; }
.drop-hint { font-size: 0.8rem; color: var(--muted); }

.detect-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.detect-card {
  background: var(--surface2);
  border-radius: 8px;
  padding: 1rem;
  text-align: center;
}

.detect-label {
  display: block;
  font-size: 0.75rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.35rem;
}

.detect-value {
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--accent-hover);
}

.settings-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.settings-grid.compact { max-width: 280px; }

.settings-grid label {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.8rem;
  color: var(--muted);
}

.settings-grid input {
  padding: 0.4rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface2);
  color: var(--text);
  font-size: 0.95rem;
}

.color-picker-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1rem;
  margin-bottom: 1rem;
}

.color-picker-row label { font-weight: 500; }

.color-picker-row input[type="number"] {
  width: 5rem;
  padding: 0.5rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface2);
  color: var(--text);
  font-size: 1.1rem;
}

.btn {
  padding: 0.55rem 1.1rem;
  border: none;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
}

.btn.primary { background: var(--accent); color: #0f172a; }
.btn.primary:hover { background: var(--accent-hover); }
.btn.secondary {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn.secondary:hover { background: var(--border); }

.detect-value-sm {
  font-size: 0.95rem;
}

.step-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 0.5rem;
}

.palette-preview-wrap {
  margin: 1rem 0;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: auto;
  max-height: 420px;
  background: #0a0e14;
}

#palettePreviewCanvas {
  display: block;
  max-width: 100%;
}

.history-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.75rem;
  margin-bottom: 1rem;
  padding: 0.75rem 1rem;
}

.history-label {
  flex: 1;
  font-size: 0.8rem;
  color: var(--muted);
  min-width: 140px;
}

.view-toggle {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.photo-toolbar-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.75rem;
}

.zoom-controls {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.zoom-btn {
  min-width: 2.25rem;
  padding: 0.35rem 0.5rem;
  font-size: 1rem;
  line-height: 1;
}

.zoom-label {
  min-width: 3rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.view-btn.active {
  background: var(--accent);
  color: #0f172a;
  border-color: var(--accent);
}

.workspace {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.photo-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.photo-toolbar h2 {
  margin: 0;
  font-size: 1.1rem;
}

#previewToggleBtn.active {
  background: var(--accent);
  color: #0f172a;
  border-color: var(--accent);
}

.workspace-photo h2 .hint {
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--muted);
}

.canvas-wrap {
  position: relative;
  overflow: auto;
  height: min(75vh, calc(100vh - 240px));
  min-height: 240px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: #0a0e14;
  text-align: center;
}

.canvas-viewport {
  display: inline-block;
  line-height: 0;
  text-align: left;
}

#checkerCanvas {
  display: block;
  cursor: crosshair;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  transform-origin: top left;
}

.workspace-inspector {
  margin-bottom: 0;
  min-height: 320px;
}

.inspector-pos {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0 0 1rem;
}

.inspector-swatches {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.swatch-block { flex: 1; text-align: center; }

.swatch-label {
  display: block;
  font-size: 0.7rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.35rem;
}

.swatch-large {
  width: 100%;
  aspect-ratio: 1;
  max-width: 110px;
  margin: 0 auto;
  border-radius: 8px;
  border: 2px solid var(--border);
}

.inspector-dmc .dmc-number {
  font-size: 2rem;
  font-weight: 700;
  margin: 0;
  color: var(--accent-hover);
}

.inspector-dmc .dmc-name {
  font-size: 1rem;
  margin: 0.25rem 0 0.5rem;
}

.inspector-dmc .dmc-meta {
  font-size: 0.8rem;
  color: var(--muted);
  margin: 0;
}

.replace-option {
  margin-bottom: 0.35rem;
  font-size: 0.85rem;
}

.alt-section-label {
  margin: 1rem 0 0.4rem;
  font-size: 0.8rem;
  font-weight: 600;
}

.hint-inline {
  font-weight: 400;
  color: var(--muted);
  font-size: 0.72rem;
}

.shade-strip {
  display: flex;
  gap: 3px;
  flex-wrap: nowrap;
}

.shade-cell {
  flex: 1;
  min-width: 0;
  aspect-ratio: 1;
  border: 2px solid transparent;
  border-radius: 4px;
  cursor: pointer;
  position: relative;
  padding: 0;
}

.shade-cell.is-center {
  border-color: var(--accent);
}

.shade-cell.is-selected {
  border-color: var(--success);
  box-shadow: 0 0 0 1px var(--success);
}

.shade-idx {
  position: absolute;
  bottom: 1px;
  left: 0;
  right: 0;
  font-size: 0.55rem;
  color: #fff;
  text-shadow: 0 0 2px #000;
  text-align: center;
}

.undo-btn {
  background: var(--surface2);
  color: var(--accent-hover);
  border: 1px solid var(--accent);
  font-weight: 600;
}

.undo-btn:not(:disabled):hover {
  background: rgba(56, 189, 248, 0.15);
}

.undo-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.dmc-input-row {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.35rem;
}

.dmc-input-row input {
  flex: 1;
  padding: 0.45rem 0.55rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface2);
  color: var(--text);
  font-size: 0.9rem;
}

.dmc-input-hint {
  margin: 0.35rem 0 0;
  font-size: 0.72rem;
  color: var(--muted);
  min-height: 1em;
}

.dmc-input-hint.error { color: #fca5a5; }

.palette-table tr.selected { background: rgba(56, 189, 248, 0.12); }

.palette-table .custom-cell.has-override { color: var(--warn); font-weight: 600; }

.palette-table .custom-swatch {
  width: 28px;
  height: 28px;
  border-radius: 4px;
  border: 1px solid rgba(255,255,255,0.15);
  display: inline-block;
  vertical-align: middle;
}

.alt-picker {
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.alt-picker h3 {
  margin: 0 0 0.5rem;
  font-size: 0.95rem;
}

.alt-custom-note {
  margin: 0.5rem 0 0;
  font-size: 0.75rem;
  color: var(--warn);
}

.results-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.results-header h2 { margin: 0; flex: 1; min-width: 180px; }

.results-summary {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0 0 1rem;
}

.palette-table-wrap { overflow-x: auto; }

.palette-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.palette-table th,
.palette-table td {
  padding: 0.5rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.palette-table th {
  color: var(--muted);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.swatch {
  width: 32px;
  height: 32px;
  border-radius: 4px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  display: inline-block;
}


footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 800px) {
  .workspace {
    grid-template-columns: 1fr;
  }
  .workspace-inspector { min-height: auto; }
}