* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #0e1116;
  --bg-panel: #161b23;
  --border: #262d38;
  --text: #e8ecf2;
  --text-dim: #8a94a3;
  --primary: #3b82f6;
  --accent: #10b981;
}

html, body { height: 100%; }

body {
  background: radial-gradient(1200px 700px at 30% -10%, #1a2230 0%, var(--bg) 60%);
  color: var(--text);
  font-family: "Segoe UI", system-ui, sans-serif;
  display: flex;
  flex-direction: column;
}

header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 22px;
  border-bottom: 1px solid var(--border);
}

h1 { font-size: 1.25rem; font-weight: 600; }

.status {
  font-size: 0.8rem;
  padding: 4px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--text-dim);
}
.status.ready { color: #34d399; border-color: #1d4a3a; background: #10281f; }
.status.working { color: #fbbf24; border-color: #4a3d1d; background: #2a2210; }
.status.error { color: #f87171; border-color: #4a1d1d; background: #2a1010; }

.lang-toggle {
  margin-left: auto;
  font-size: 0.8rem;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: 999px;
  background: #1f2632;
  border: 1px solid var(--border);
  color: var(--text);
  cursor: pointer;
}
.lang-toggle:hover { filter: brightness(1.25); }

main {
  flex: 1;
  display: flex;
  min-height: 0;
}

.viewport {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

#cube-canvas {
  flex: 1;
  width: 100%;
  min-height: 0;
  cursor: grab;
  touch-action: none;
}
#cube-canvas:active { cursor: grabbing; }
#cube-canvas.painting { cursor: crosshair; }
#cube-canvas.painting:active { cursor: crosshair; }

.hint {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.78rem;
  padding: 8px 12px 14px;
}

.panel {
  width: 320px;
  flex-shrink: 0;
  border-left: 1px solid var(--border);
  background: var(--bg-panel);
  padding: 18px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.panel h2 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  font-weight: 600;
}

.actions { display: flex; gap: 8px; }

button {
  font: inherit;
  color: var(--text);
  background: #1f2632;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 9px 14px;
  cursor: pointer;
  transition: filter 0.12s, transform 0.05s;
}
button:hover:not(:disabled) { filter: brightness(1.2); }
button:active:not(:disabled) { transform: scale(0.97); }
button:disabled { opacity: 0.45; cursor: default; }

.actions button { flex: 1; font-weight: 600; font-size: 0.82rem; padding: 9px 4px; white-space: nowrap; }
button.primary { background: var(--primary); border-color: transparent; }
button.accent { background: var(--accent); border-color: transparent; color: #06281c; }

.speed-row {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.85rem;
  color: var(--text-dim);
}
.speed-row input { flex: 1; accent-color: var(--primary); }

.moves-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
}
.move-btn { padding: 8px 0; font-family: Consolas, monospace; font-weight: 600; }

.solution {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  min-height: 40px;
}
.chip {
  font-family: Consolas, monospace;
  font-size: 0.85rem;
  padding: 4px 9px;
  border-radius: 6px;
  background: #1f2632;
  border: 1px solid var(--border);
  color: var(--text-dim);
}
.chip.active { background: var(--primary); color: #fff; border-color: transparent; }
.chip.done { color: #34d399; border-color: #1d4a3a; }

.section-hint {
  font-size: 0.8rem;
  color: var(--text-dim);
  line-height: 1.45;
}
.section-hint b { color: var(--text); }

.stepper[hidden] { display: none; }
.stepper {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: #10151d;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
}
.step-desc {
  font-size: 0.92rem;
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 22px;
}
.swatch {
  display: inline-block;
  width: 14px;
  height: 14px;
  border-radius: 4px;
  border: 1px solid rgba(0,0,0,0.4);
  flex-shrink: 0;
}
.stepper-controls {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.stepper-controls button { padding: 7px 10px; font-size: 0.82rem; }
.step-progress {
  margin-left: auto;
  font-size: 0.78rem;
  color: var(--text-dim);
  white-space: nowrap;
}

.palette {
  display: flex;
  gap: 8px;
}
.palette-swatch {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  border: 2px solid transparent;
  padding: 0;
  cursor: pointer;
}
.palette-swatch.selected {
  border-color: #fff;
  box-shadow: 0 0 0 2px var(--primary);
}

.edit-row { display: flex; gap: 8px; }
.edit-row button { flex: 1; font-size: 0.8rem; padding: 8px 4px; line-height: 1.2; }
#btn-edit.active {
  background: var(--primary);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 0 0 2px rgba(59,130,246,0.35);
}

.net-actions { display: flex; gap: 8px; }
.net-actions button { flex: 1; font-size: 0.85rem; padding: 8px 6px; }

.net-msg { font-size: 0.8rem; line-height: 1.4; min-height: 1em; }
.net-msg.error { color: #f87171; }
.net-msg.ok { color: #34d399; }

@media (max-width: 760px) {
  main { flex-direction: column; }
  .panel { width: 100%; border-left: none; border-top: 1px solid var(--border); }
  .viewport { min-height: 46vh; }
}