/* ── Helmholtz module layout ── */
html, body {
  height: 100%;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* ── Sub-nav bar (below main nav) ── */
.sub-nav-bar {
  height: 34px;
  background: var(--bg-primary);
  border-bottom: 1px solid rgba(108,99,255,0.1);
  display: flex;
  align-items: center;
  padding: 0 20px;
  gap: 16px;
  flex-shrink: 0;
}

.sub-nav-item {
  font-family: 'Inter', sans-serif;
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text-muted);
  background: none;
  border: none;
  padding: 5px 14px;
  border-radius: 6px;
  cursor: pointer;
  transition: color 0.15s, background 0.15s;
  display: flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
}
.sub-nav-item:hover {
  color: var(--text-secondary);
  background: rgba(108,99,255,0.08);
}
.sub-nav-item.active {
  color: var(--text-primary);
  background: rgba(108,99,255,0.2);
}
.sub-nav-icon {
  width: 16px; height: 16px;
  flex-shrink: 0;
}

/* ── App container ── */
.app {
  display: flex;
  flex: 1;
  width: 100%;
  overflow: hidden;
}

/* ── Left: Display panel ── */
.display-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 18px 24px;
  position: relative;
}
.display-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 30% 20%, rgba(0,212,170,0.06) 0%, transparent 60%),
              radial-gradient(ellipse at 70% 80%, rgba(108,99,255,0.05) 0%, transparent 60%);
  pointer-events: none;
}

h1 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 10px;
  background: linear-gradient(135deg, var(--accent-3), var(--accent-1));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-align: center;
  position: relative;
  z-index: 1;
}

.canvas-wrap {
  position: relative;
  z-index: 1;
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 12px;
  border: 1px solid rgba(108,99,255,0.15);
  box-shadow: 0 8px 32px rgba(0,0,0,0.3);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.canvas-container {
  position: relative;
  width: 800px;
  height: 600px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  cursor: crosshair;
}
.canvas-container canvas {
  position: absolute;
  top: 0;
  left: 0;
  display: block;
  border-radius: var(--radius-sm);
}
#fieldCanvas {
  image-rendering: pixelated;
  z-index: 0;
}
#overlayCanvas {
  z-index: 1;
  pointer-events: none;
}

/* When in placement mode, show crosshair */
.canvas-container.placing {
  cursor: crosshair;
}
.canvas-container.panning {
  cursor: grab;
}
.canvas-container.panning:active {
  cursor: grabbing;
}

.canvas-label {
  margin-top: 8px;
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
}

.status-bar {
  margin-top: 8px;
  font-size: 0.78rem;
  color: var(--text-muted);
  font-family: 'Fira Code', monospace;
  position: relative;
  z-index: 1;
}

/* ── Right: Control panel ── */
.control-panel {
  width: 320px;
  background: var(--bg-slide);
  border-left: 1px solid rgba(108,99,255,0.12);
  overflow-y: auto;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  flex-shrink: 0;
}
.control-panel::-webkit-scrollbar { width: 6px; }
.control-panel::-webkit-scrollbar-track { background: transparent; }
.control-panel::-webkit-scrollbar-thumb { background: rgba(108,99,255,0.3); border-radius: 3px; }

.panel-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--accent-1);
  text-align: center;
  padding-bottom: 8px;
  border-bottom: 2px solid rgba(108,99,255,0.2);
}

.section {
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  border: 1px solid rgba(108,99,255,0.1);
}
.section h3 {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--accent-3);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.subsection-title {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin: 0 0 8px 0;
}

.separator {
  height: 1px;
  background: rgba(108,99,255,0.12);
  margin: 10px 0;
}

/* ── Slider ── */
.slider-group {
  display: flex;
  flex-direction: column;
  gap: 3px;
  margin-bottom: 10px;
}
.slider-group:last-child { margin-bottom: 0; }
.slider-group label {
  font-size: 0.78rem;
  color: var(--text-secondary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.slider-group label .param-name { font-weight: 500; }
.slider-group label .val {
  font-family: 'Fira Code', monospace;
  font-size: 0.72rem;
  color: var(--accent-4);
}
.slider-group input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: rgba(108,99,255,0.15);
  outline: none;
}
.slider-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--accent-1);
  cursor: pointer;
  transition: transform 0.1s;
}
.slider-group input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.2); }
.slider-group input[type="range"]::-moz-range-thumb {
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--accent-1);
  cursor: pointer;
  border: none;
}

/* ── Select ── */
.select-group { margin-bottom: 10px; }
.select-group:last-child { margin-bottom: 0; }
.select-group label {
  font-size: 0.78rem;
  color: var(--text-secondary);
  display: block;
  margin-bottom: 4px;
  font-weight: 500;
}
.select-group select {
  width: 100%;
  padding: 6px 10px;
  background: rgba(108,99,255,0.1);
  border: 1px solid rgba(108,99,255,0.2);
  border-radius: 6px;
  color: var(--text-primary);
  font-family: 'Inter', sans-serif;
  font-size: 0.82rem;
  outline: none;
  cursor: pointer;
}
.select-group select:focus { border-color: var(--accent-1); }
.select-group select option { background: var(--bg-card); }

/* ── Toggle ── */
.toggle-group {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}
.toggle-group label {
  font-size: 0.78rem;
  color: var(--text-secondary);
  cursor: pointer;
}
.toggle-group input[type="checkbox"] {
  accent-color: var(--accent-1);
  width: 16px; height: 16px;
  cursor: pointer;
}

/* ── Number input rows ── */
.input-row {
  display: flex;
  gap: 8px;
  margin-bottom: 8px;
}
.input-group {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.input-group label {
  font-size: 0.72rem;
  color: var(--text-secondary);
  font-weight: 500;
}
.input-group input[type="number"] {
  width: 100%;
  padding: 5px 8px;
  background: rgba(108,99,255,0.1);
  border: 1px solid rgba(108,99,255,0.2);
  border-radius: 6px;
  color: var(--text-primary);
  font-family: 'Fira Code', monospace;
  font-size: 0.78rem;
  outline: none;
  box-sizing: border-box;
}
.input-group input[type="number"]:focus {
  border-color: var(--accent-1);
}

/* ── Buttons ── */
.action-btn {
  width: 100%;
  padding: 8px 0;
  margin-top: 6px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  border: none;
  border-radius: 8px;
  color: #fff;
  font-family: 'Inter', sans-serif;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s;
  letter-spacing: 0.02em;
}
.action-btn:hover { opacity: 0.88; transform: translateY(-1px); }
.action-btn:active { transform: scale(0.98); }
.action-btn.active {
  background: linear-gradient(135deg, var(--accent-3), var(--accent-1));
  box-shadow: 0 0 12px rgba(0,212,170,0.3);
}
.action-btn.danger {
  background: linear-gradient(135deg, var(--accent-2), #ff6b6b);
  margin-top: 8px;
}

.placement-hint {
  font-size: 0.72rem;
  color: var(--accent-3);
  margin-top: 6px;
  padding: 6px 10px;
  background: rgba(0,212,170,0.08);
  border-radius: 6px;
  border: 1px solid rgba(0,212,170,0.2);
}
.placement-hint.hidden { display: none; }

/* ── Placement warning ── */
.placement-warning {
  font-size: 0.72rem;
  color: var(--accent-2);
  margin-top: 6px;
  padding: 6px 10px;
  background: rgba(233,69,96,0.08);
  border-radius: 6px;
  border: 1px solid rgba(233,69,96,0.3);
}
.placement-warning.hidden { display: none; }

/* ── Bragg indicators ── */
.bragg-indicator {
  font-size: 0.68rem;
  font-family: 'Fira Code', monospace;
  color: var(--accent-4);
  margin-top: 2px;
  padding: 2px 0;
  opacity: 0.85;
}
.bragg-indicator.hidden { display: none; }

/* ── Bragg tick marks on sliders ── */
.bragg-ticks {
  position: relative;
  width: 100%;
  height: 8px;
  margin-top: -2px;
  pointer-events: none;
}
.bragg-tick {
  position: absolute;
  width: 2px;
  height: 8px;
  background: var(--accent-2);
  transform: translateX(-1px);
  opacity: 0.8;
  border-radius: 1px;
}

/* ── Hidden helper ── */
.slider-group.hidden, .select-group.hidden { display: none; }

.lattice-hint {
  font-size: 0.72rem;
  color: var(--text-muted);
  margin-top: 6px;
  margin-bottom: 0;
}

.scatterer-count {
  font-size: 0.78rem;
  color: var(--text-secondary);
  font-family: 'Fira Code', monospace;
  margin-bottom: 4px;
}

/* ── Info icon tooltip ── */
.info-icon {
  cursor: help;
  font-size: 0.85rem;
  color: var(--text-muted);
  position: relative;
}
.info-icon:hover { color: var(--accent-1); }
.info-icon[data-tooltip]:hover::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 0;
  min-width: 220px;
  padding: 8px 10px;
  background: var(--bg-card);
  border: 1px solid rgba(108,99,255,0.25);
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
  font-size: 0.72rem;
  color: var(--text-secondary);
  line-height: 1.5;
  white-space: pre-line;
  z-index: 50;
  font-weight: 400;
}

/* ── Loading overlay ── */
.loading {
  position: fixed; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: rgba(15,15,26,0.85);
  z-index: 200;
  font-size: 1.1rem;
  color: var(--accent-1);
}
.loading.hidden { display: none; }

/* ── Fullscreen tweaks ── */
.canvas-wrap:fullscreen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--bg-primary);
  padding: 0;
}
.canvas-wrap:fullscreen .canvas-container {
  width: 100vw;
  height: calc(100vh - 40px);
}
.canvas-wrap:fullscreen .canvas-container canvas {
  width: 100%;
  height: 100%;
}

/* ── Atom picker ── */
.atom-picker { margin-top: 6px; }
.atom-picker.hidden { display: none; }

.atom-quick-btns {
  display: flex;
  gap: 5px;
  margin-bottom: 5px;
}
.atom-quick-btn {
  padding: 2px 10px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.atom-quick-btn:hover {
  background: rgba(108,99,255,0.12);
  color: var(--text-primary);
}
.atom-quick-btn.active {
  background: rgba(245,166,35,0.25);
  border-color: rgba(245,166,35,0.6);
  color: #f5a623;
}

.atom-search-wrap {
  position: relative;
  margin-bottom: 5px;
}
.atom-search-wrap input {
  width: 100%;
  box-sizing: border-box;
  padding: 3px 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 0.78rem;
  font-family: 'Inter', sans-serif;
}
.atom-search-wrap input::placeholder {
  color: var(--text-muted);
}

.atom-suggestions {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  max-height: 160px;
  overflow-y: auto;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 0 0 4px 4px;
  z-index: 100;
}
.atom-suggestions.hidden { display: none; }

.atom-suggestion-item {
  padding: 4px 8px;
  font-size: 0.78rem;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
}
.atom-suggestion-item:hover {
  background: rgba(108,99,255,0.15);
  color: var(--text-primary);
}
.atom-suggestion-item .sym {
  font-weight: 600;
  color: #f5a623;
  min-width: 28px;
}

.selected-atom {
  font-size: 0.78rem;
  color: var(--text-muted);
  padding: 2px 0;
}
.selected-atom .sym {
  font-weight: 600;
  color: #f5a623;
}