:root {
  --bg: #0d0f13;
  --panel: #15181f;
  --panel-2: #1b1f28;
  --line: #262b36;
  --text: #e7e9ee;
  --text-dim: #8a92a3;
  --accent: #4fd1c5;
  --accent-dim: #2c6e69;
  --warn: #f5a623;
  --danger: #e0616b;
  --radius: 10px;
  --mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;
  --sans: 'Inter', system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }

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

.mono { font-family: var(--mono); }

.app {
  max-width: 1180px;
  margin: 0 auto;
  padding: 24px 20px 60px;
}

/* ---------- topbar ---------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 20px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-grid {
  display: grid;
  grid-template-columns: repeat(3, 8px);
  grid-template-rows: repeat(3, 8px);
  gap: 3px;
  flex-shrink: 0;
}
.brand-grid i {
  display: block;
  background: var(--accent);
  border-radius: 2px;
}
.brand-grid i:nth-child(1) { background: #e0616b; }
.brand-grid i:nth-child(2) { background: #4a7ce0; }
.brand-grid i:nth-child(3) { background: #e0616b; }
.brand-grid i:nth-child(4) { background: #e7e9ee; }
.brand-grid i:nth-child(5) { background: #4a7ce0; }
.brand-grid i:nth-child(6) { background: #e7e9ee; }
.brand-grid i:nth-child(7) { background: #e0616b; }
.brand-grid i:nth-child(8) { background: #e0c23a; }
.brand-grid i:nth-child(9) { background: #e0c23a; }

.brand-text h1 {
  font-size: 15px;
  letter-spacing: 0.14em;
  margin: 0;
  font-weight: 600;
}
.subtitle {
  margin: 3px 0 0;
  color: var(--text-dim);
  font-size: 12px;
}

.status {
  font-size: 12px;
  color: var(--text-dim);
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 20px;
}
.status.active { color: var(--accent); border-color: var(--accent-dim); }
.status.error { color: var(--danger); border-color: var(--danger); }

/* ---------- layout ---------- */

.layout {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 20px;
  align-items: start;
}

@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
}

/* ---------- dropzone ---------- */

.dropzone-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 70px 20px;
  border: 1.5px dashed var(--line);
  border-radius: var(--radius);
  text-align: center;
}
.dropzone-inner.drag {
  border-color: var(--accent);
  background: rgba(79, 209, 197, 0.05);
}
.dz-icon {
  font-size: 26px;
  color: var(--accent);
}
.dropzone-inner p { margin: 0; color: var(--text-dim); font-size: 14px; }
.hint { color: var(--text-dim); font-size: 11.5px; }

.btn {
  background: var(--accent);
  color: #06231f;
  border: none;
  padding: 9px 18px;
  border-radius: 7px;
  font-family: var(--sans);
  font-weight: 600;
  font-size: 13px;
  cursor: pointer;
  transition: filter 0.15s ease;
}
.btn:hover { filter: brightness(1.1); }
.btn.ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--line);
  font-weight: 500;
}
.btn.ghost:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- step banner ---------- */

.step-banner {
  display: flex;
  align-items: center;
  gap: 12px;
  background: rgba(79, 209, 197, 0.12);
  border: 1px solid var(--accent-dim);
  border-radius: 8px;
  padding: 12px 16px;
  margin-bottom: 14px;
}
.step-banner.warn {
  background: rgba(245, 166, 35, 0.12);
  border-color: var(--warn);
}
.step-banner.done {
  background: rgba(79, 209, 197, 0.08);
  border-color: var(--line);
}
.step-badge {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  background: var(--accent);
  color: #06231f;
  padding: 3px 9px;
  border-radius: 20px;
  flex-shrink: 0;
}
.step-banner.warn .step-badge { background: var(--warn); }
.step-text {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text);
}

/* ---------- stage / canvas ---------- */

.stage {
  position: relative;
  width: 100%;
  max-height: 68vh;
  overflow: auto;
  border-radius: var(--radius);
  background: #000;
  line-height: 0;
}
#photoCanvas, #overlayCanvas {
  display: block;
}
#overlayCanvas {
  position: absolute;
  top: 0; left: 0;
  cursor: crosshair;
}

.zoom-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}
.zoom-btn {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--text);
  font-size: 15px;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}
.zoom-btn:hover { border-color: var(--accent); color: var(--accent); }
.zoom-label {
  font-size: 12px;
  color: var(--text-dim);
  min-width: 40px;
  text-align: center;
}

.canvas-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 12px;
  flex-wrap: wrap;
}
.toolbar-left { display: flex; gap: 8px; align-items: center; }
.canvas-toolbar .hint { color: var(--text-dim); }

/* ---------- controls ---------- */

.control-group { margin-bottom: 18px; }
.control-label {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  margin-bottom: 8px;
}
.control-label .value { color: var(--accent); }
.control-desc {
  margin: 8px 0 0;
  font-size: 11.5px;
  color: var(--text-dim);
  line-height: 1.4;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.divider {
  height: 1px;
  background: var(--line);
  margin: 18px 0;
}

/* ---------- results ---------- */

.result-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  margin-bottom: 12px;
  color: var(--text-dim);
}
.result-state { color: var(--text-dim); }
.result-state.ok { color: var(--accent); }
.result-state.warn { color: var(--warn); }

.swatch-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  margin-bottom: 14px;
}
.swatch {
  aspect-ratio: 1;
  border-radius: 6px;
  border: 1px solid var(--line);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 5px;
  position: relative;
  cursor: pointer;
  transition: transform 0.1s ease;
}
.swatch:hover { transform: scale(1.05); box-shadow: 0 0 0 2px var(--accent); }
.swatch.manual::before {
  content: '✎';
  position: absolute;
  top: 3px;
  right: 4px;
  font-size: 10px;
  color: rgba(0,0,0,0.6);
}
.swatch span {
  font-family: var(--mono);
  font-size: 10px;
  padding: 1px 5px;
  border-radius: 3px;
  background: rgba(0,0,0,0.55);
  color: #fff;
  letter-spacing: 0.02em;
}
.swatch.empty {
  background: var(--panel-2) !important;
  border-style: dashed;
  cursor: default;
}
.swatch.empty:hover { transform: none; box-shadow: none; }
.swatch.empty span { display: none; }

.swatch-hint {
  margin-top: -6px;
}

.facelet-code {
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-dim);
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: 7px;
  padding: 10px 12px;
  text-align: center;
}

/* ---------- legend ---------- */

/* ---------- face selector (net cross) ---------- */

.net-selector-panel { margin-bottom: 20px; }

.net-selector-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  margin-bottom: 14px;
  color: var(--text-dim);
}
.net-progress { color: var(--accent); }

.face-cross {
  display: grid;
  grid-template-columns: repeat(4, 74px);
  grid-template-rows: repeat(3, 74px);
  gap: 6px;
  justify-content: center;
  margin-bottom: 8px;
}

.face-slot {
  border: 1.5px solid var(--line);
  border-radius: 8px;
  background: var(--panel-2);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  transition: border-color 0.15s ease, transform 0.1s ease;
  position: relative;
  overflow: hidden;
}
.face-slot:hover { border-color: var(--accent); transform: scale(1.03); }
.face-slot.active { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(79,209,197,0.35); }
.face-slot.done { border-style: solid; }
.face-slot .face-letter {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 13px;
  color: var(--text-dim);
  z-index: 1;
  background: rgba(0,0,0,0.5);
  padding: 1px 6px;
  border-radius: 4px;
}
.face-slot.done .face-letter { color: #fff; }
.face-slot .mini-grid {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
}
.face-slot .mini-grid div { border: 0.5px solid rgba(0,0,0,0.25); }

.protocol { margin-top: 4px; }

/* ---------- net export panel ---------- */

.net-export-panel { margin-top: 20px; }

.net-export-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  margin-bottom: 16px;
  color: var(--text-dim);
}
.net-export-state { color: var(--warn); }
.net-export-state.ok { color: var(--accent); }

.net-body {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 28px;
  align-items: start;
}
@media (max-width: 780px) {
  .net-body { grid-template-columns: 1fr; }
}

.net-diagram {
  display: grid;
  grid-template-columns: repeat(4, 52px);
  grid-template-rows: repeat(3, 52px);
  gap: 4px;
}
.net-face {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
}
.net-face div { border: 0.5px solid rgba(0,0,0,0.25); }
.net-face.placeholder {
  background: var(--panel-2);
  display: flex;
  align-items: center;
  justify-content: center;
}
.net-face.placeholder span {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-dim);
}

.net-side { min-width: 0; }

.facelet-string {
  width: 100%;
  resize: none;
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: 7px;
  color: var(--text);
  font-size: 13px;
  letter-spacing: 0.05em;
  padding: 10px 12px;
  margin-top: 8px;
}

.net-actions {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.net-validation {
  margin-top: 10px;
  font-size: 11.5px;
  color: var(--text-dim);
  line-height: 1.6;
  white-space: pre-line;
}
.net-validation.warn { color: var(--warn); }
.net-validation.ok { color: var(--accent); }

.solve-btn {
  width: 100%;
  margin-top: 14px;
  padding: 11px;
  font-size: 14px;
}
.solve-btn:disabled {
  background: var(--panel-2);
  color: var(--text-dim);
  cursor: not-allowed;
}

.solve-result {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-dim);
  word-break: break-word;
}
.solve-result.ok { color: var(--text); }
.solve-result.warn { color: var(--warn); }
.solve-count {
  color: var(--accent);
  font-weight: 700;
}

/* ---------- legend (details/summary blocks) ---------- */

.legend summary {
  cursor: pointer;
  font-size: 12px;
  color: var(--text-dim);
  letter-spacing: 0.04em;
}
.legend summary:hover { color: var(--accent); }
.legend ol {
  margin: 10px 0 0;
  padding-left: 18px;
  font-size: 12px;
  color: var(--text-dim);
  line-height: 1.6;
}

/* ---------- 3D визуализация решения ---------- */

.viz-panel { margin-top: 20px; }

.viz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  margin-bottom: 16px;
  color: var(--text-dim);
}
.viz-state { color: var(--accent); }

.viz-body {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 20px;
  align-items: start;
}
@media (max-width: 780px) {
  .viz-body { grid-template-columns: 1fr; }
}

.viz-canvas-wrap {
  width: 100%;
  aspect-ratio: 1;
  max-width: 360px;
  border-radius: var(--radius);
  background: radial-gradient(circle at 35% 30%, #1c2028, #0a0b0e);
  border: 1px solid var(--line);
  overflow: hidden;
  position: relative;
}
.viz-canvas-wrap canvas {
  display: block;
  width: 100% !important;
  height: 100% !important;
  cursor: grab;
}
.viz-canvas-wrap canvas:active { cursor: grabbing; }

.viz-side { min-width: 0; }

.move-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}

.move-token {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  padding: 6px 11px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--text);
  cursor: pointer;
  transition: border-color 0.12s ease, background 0.12s ease;
}
.move-token:hover { border-color: var(--accent); color: var(--accent); }
.move-token.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #06231f;
}