/**
 * 3D Interactive Wave & Acoustics Laboratory
 * Modern Dark-Themed Physics Laboratory Stylesheet
 */

:root {
  --bg-main: #090d16;
  --bg-panel: #0f172a;
  --bg-card: #1e293b;
  --bg-input: #0b1120;
  --border-color: #334155;
  --border-light: #475569;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-cyan: #38bdf8;
  --accent-blue: #2563eb;
  --accent-green: #10b981;
  --accent-rose: #f43f5e;
  --accent-gold: #fbbf24;
  --accent-purple: #a855f7;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --radius: 8px;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-primary);
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* =========================================================
   TOP NAVIGATION & CONTROL HEADER
   ========================================================= */
.top-header {
  height: 56px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  z-index: 100;
  flex-shrink: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-icon {
  font-size: 24px;
}

.brand h1 {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.3px;
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-badge {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 12px;
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-cyan);
  border: 1px solid rgba(56, 189, 248, 0.3);
}

.header-center-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn-ctrl {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s ease;
}

.btn-ctrl:hover {
  background: #334155;
  border-color: var(--border-light);
}

.btn-ctrl.paused {
  background: rgba(244, 63, 94, 0.2);
  color: #fca5a5;
  border-color: var(--accent-rose);
}

.btn-ctrl.muted {
  color: var(--text-muted);
}

.sim-speed-ctrl {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--text-secondary);
}

.sim-speed-ctrl select {
  background: var(--bg-input);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 5px 8px;
  border-radius: 6px;
  font-size: 12px;
  cursor: pointer;
}

.volume-ctrl {
  display: flex;
  align-items: center;
  gap: 6px;
}

.volume-ctrl input[type="range"] {
  width: 75px;
}

.wave-model-toggle-group {
  display: flex;
  background: var(--bg-input);
  padding: 2px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  margin-right: 8px;
}

.btn-wave-model {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 4px;
}

.btn-wave-model:hover {
  color: #fff;
}

.btn-wave-model.active {
  background: linear-gradient(135deg, #10b981, #059669);
  color: #fff;
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.4);
}

.dimension-toggle-group {
  display: flex;
  background: var(--bg-input);
  padding: 2px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  margin-right: 8px;
}

.btn-dim-toggle {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 4px;
}

.btn-dim-toggle.active {
  background: linear-gradient(135deg, #0284c7, #2563eb);
  color: #fff;
  box-shadow: 0 0 10px rgba(37, 99, 235, 0.4);
}

.mode-toggle-group {
  display: flex;
  background: var(--bg-input);
  padding: 2px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
}

.btn-toggle-mode {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-toggle-mode.active {
  background: var(--accent-blue);
  color: #fff;
}

/* =========================================================
   MAIN APP BODY (Left Panel, 3D Canvas, Right Panel)
   ========================================================= */
.main-content-layout {
  flex: 1;
  display: flex;
  position: relative;
  overflow: hidden;
}

/* Left & Right Panels */
.side-panel {
  width: 290px;
  background: var(--bg-panel);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  z-index: 20;
  flex-shrink: 0;
}

.right-panel {
  width: 320px;
  border-right: none;
  border-left: 1px solid var(--border-color);
}

.panel-section {
  padding: 14px 16px;
  border-bottom: 1px solid rgba(51, 65, 85, 0.6);
}

.section-label {
  display: block;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.preset-dropdown {
  width: 100%;
  background: var(--bg-input);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 8px 10px;
  border-radius: var(--radius);
  font-size: 13px;
  outline: none;
  cursor: pointer;
}

.preset-dropdown:focus {
  border-color: var(--accent-cyan);
}

/* Object buttons */
.object-buttons-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.btn-tool {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 8px 10px;
  border-radius: var(--radius);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: all 0.15s;
}

.btn-tool:hover {
  background: #334155;
  border-color: var(--accent-cyan);
  transform: translateY(-1px);
}

/* Visual modes */
.mode-select-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
}

.btn-mode {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 6px 2px;
  font-size: 11px;
  font-weight: 600;
  border-radius: 5px;
  cursor: pointer;
  text-align: center;
}

.btn-mode.active {
  background: rgba(56, 189, 248, 0.2);
  color: var(--accent-cyan);
  border-color: var(--accent-cyan);
}

/* Checkbox lists */
.checkbox-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.chk-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-secondary);
  cursor: pointer;
}

.chk-label input[type="checkbox"] {
  accent-color: var(--accent-cyan);
  cursor: pointer;
}

/* Camera buttons */
.cam-buttons-grid, .share-buttons-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.btn-cam, .btn-secondary {
  background: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  padding: 6px 8px;
  border-radius: 6px;
  font-size: 11px;
  cursor: pointer;
  text-align: center;
}

.btn-cam:hover, .btn-secondary:hover {
  color: var(--text-primary);
  border-color: var(--border-light);
  background: #334155;
}

/* =========================================================
   CENTER 3D VIEWPORT
   ========================================================= */
.viewport-wrapper {
  flex: 1;
  position: relative;
  background: var(--bg-main);
  overflow: hidden;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

#viewport-3d {
  width: 100%;
  height: 100%;
  touch-action: none;
}

#viewport-3d canvas {
  touch-action: none;
}

.viewport-overlay-hints {
  position: absolute;
  top: 14px;
  left: 16px;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.hint-pill {
  background: rgba(15, 23, 42, 0.82);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(51, 65, 85, 0.8);
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 11px;
  color: var(--text-secondary);
}

.hint-pill strong {
  color: var(--accent-cyan);
}

/* =========================================================
   RIGHT PANEL: INSPECTOR & EDUCATIONAL GUIDE
   ========================================================= */
.right-panel-tabs {
  display: flex;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-input);
}

.tab-btn {
  flex: 1;
  background: transparent;
  border: none;
  padding: 10px 0;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  border-bottom: 2px solid transparent;
}

.tab-btn.active {
  color: var(--accent-cyan);
  border-bottom-color: var(--accent-cyan);
}

.right-tab-content {
  flex: 1;
  overflow-y: auto;
  padding: 14px;
}

.empty-inspector {
  text-align: center;
  padding: 30px 14px;
  color: var(--text-muted);
}

.empty-inspector .inspector-icon {
  font-size: 36px;
  margin-bottom: 12px;
  opacity: 0.6;
}

.empty-inspector h4 {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.empty-inspector p {
  font-size: 12px;
  line-height: 1.5;
}

.inspector-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.inspector-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
}

.title-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}

.color-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}

.inspector-header h4 {
  font-size: 14px;
  font-weight: 700;
}

.param-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.param-header {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-secondary);
}

.param-header strong {
  color: var(--accent-cyan);
  font-family: monospace;
}

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

.computed-badge {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 12px;
  display: flex;
  justify-content: space-between;
}

.computed-badge strong {
  color: var(--accent-gold);
  font-family: monospace;
}

.param-group-coords {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  padding: 10px;
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.coord-label {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
}

.coord-inputs {
  display: flex;
  gap: 10px;
}

.coord-inputs label {
  font-size: 12px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 4px;
}

.coord-inputs input[type="number"] {
  width: 70px;
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 3px 6px;
  border-radius: 4px;
  font-size: 12px;
}

/* Educational Card */
.edu-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.edu-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.edu-badge {
  font-size: 11px;
  font-weight: 700;
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 2px 8px;
  border-radius: 10px;
}

.edu-badge.free {
  background: rgba(168, 85, 247, 0.15);
  color: var(--accent-purple);
  border-color: rgba(168, 85, 247, 0.3);
}

.edu-tag {
  font-size: 11px;
  color: var(--text-muted);
}

.edu-title {
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  line-height: 1.3;
}

.edu-desc {
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-secondary);
}

.edu-section {
  background: var(--bg-card);
  border-left: 3px solid;
  padding: 10px 12px;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.edu-section.observation {
  border-left-color: var(--accent-cyan);
}

.edu-section.why {
  border-left-color: var(--accent-purple);
}

.edu-section.try-this {
  border-left-color: var(--accent-gold);
}

.section-title {
  font-size: 12px;
  color: var(--text-primary);
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.section-text {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.45;
}

/* =========================================================
   BOTTOM OSCILLOSCOPE & MEASUREMENT PANEL
   ========================================================= */
.bottom-measurement-panel {
  height: 200px;
  background: var(--bg-panel);
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  z-index: 30;
  flex-shrink: 0;
}

.measurements-banner {
  height: 38px;
  background: var(--bg-input);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
}

.readout-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
}

.readout-label {
  color: var(--text-muted);
}

.readout-val {
  font-family: monospace;
  font-weight: 700;
  color: var(--text-primary);
}

.val-condition {
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 11px;
}

.val-condition.constructive {
  background: rgba(16, 185, 129, 0.2);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.4);
}

.val-condition.destructive {
  background: rgba(244, 63, 94, 0.2);
  color: #fb7185;
  border: 1px solid rgba(244, 63, 94, 0.4);
}

.val-condition.intermediate {
  background: rgba(251, 191, 36, 0.2);
  color: #fde047;
  border: 1px solid rgba(251, 191, 36, 0.4);
}

.scope-body {
  flex: 1;
  display: flex;
  position: relative;
}

.scope-canvas-container {
  flex: 1;
  position: relative;
  background: #0b0f19;
}

#oscilloscope-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.scope-controls-strip {
  width: 260px;
  background: var(--bg-panel);
  border-left: 1px solid var(--border-color);
  padding: 10px 14px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.trace-toggles {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.trace-chk {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  color: var(--text-secondary);
  cursor: pointer;
}

.trace-pill {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  display: inline-block;
}

.btn-freeze {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 5px 8px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
}

.btn-freeze.active {
  background: var(--accent-rose);
  color: #fff;
  border-color: var(--accent-rose);
}

/* Toggle Switch Component */
.toggle-switch {
  position: relative;
  display: inline-block;
  width: 36px;
  height: 20px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider-toggle {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  transition: 0.3s;
  border-radius: 20px;
}

.slider-toggle:before {
  position: absolute;
  content: "";
  height: 14px;
  width: 14px;
  left: 2px;
  bottom: 2px;
  background-color: var(--text-secondary);
  transition: 0.3s;
  border-radius: 50%;
}

input:checked + .slider-toggle {
  background-color: var(--accent-blue);
  border-color: var(--accent-blue);
}

input:checked + .slider-toggle:before {
  transform: translateX(16px);
  background-color: #fff;
}

/* =========================================================
   ADVANCED FEATURES: STYLES FOR PHASE WHEEL, PROBES & MISSIONS
   ========================================================= */
.sync-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 12px;
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.35);
}

.btn-lock {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 5px;
  cursor: pointer;
}

.btn-lock.locked {
  background: rgba(244, 63, 94, 0.2);
  color: #fb7185;
  border-color: var(--accent-rose);
}

.name-edit-input {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 14px;
  padding: 2px 4px;
  border-radius: 4px;
  width: 140px;
}

.name-edit-input:focus {
  background: var(--bg-input);
  border-color: var(--accent-cyan);
}

.vector-inspector-box {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 8px 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.vec-row {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-muted);
}

.vec-row strong {
  color: var(--accent-cyan);
  font-family: monospace;
}

.panel-section-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 12px;
  margin-bottom: 12px;
}

.card-title {
  font-size: 13px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 4px;
}

.card-desc {
  font-size: 11px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.card-header-flex {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--text-secondary);
  padding: 4px 0;
  border-bottom: 1px solid rgba(51, 65, 85, 0.4);
}

.stat-row strong {
  color: var(--accent-gold);
  font-family: monospace;
}

.strobe-row {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.probes-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 11px;
  margin-top: 6px;
}

.probes-table th, .probes-table td {
  padding: 5px 6px;
  border-bottom: 1px solid rgba(51, 65, 85, 0.4);
  text-align: left;
}

.probes-table th {
  color: var(--text-muted);
}

.probes-table td strong {
  font-family: monospace;
  color: var(--accent-cyan);
}

.empty-hint {
  font-size: 11px;
  color: var(--text-muted);
  font-style: italic;
  padding: 6px 0;
}

/* Mission / Challenge Card */
.mission-box {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 10px;
}

.mission-badge {
  align-self: flex-start;
  font-size: 10px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 10px;
  background: rgba(168, 85, 247, 0.2);
  color: var(--accent-purple);
  border: 1px solid rgba(168, 85, 247, 0.4);
}

.mission-title {
  font-size: 14px;
  font-weight: 700;
  color: #fff;
}

.mission-desc {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.4;
}

.mission-hint {
  font-size: 11px;
  color: var(--accent-gold);
  background: rgba(251, 191, 36, 0.1);
  padding: 6px 8px;
  border-radius: 4px;
}

.mission-actions {
  display: flex;
  gap: 6px;
}

.btn-secondary-sm {
  flex: 1;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 6px 8px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
}

.btn-secondary-sm:hover {
  background: #334155;
  color: #fff;
}

.btn-sm {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 11px;
  cursor: pointer;
}

/* Annotation Toolbar */
.annotation-toolbar {
  position: absolute;
  top: 14px;
  right: 16px;
  background: rgba(15, 23, 42, 0.9);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 6px 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 100;
}

.annot-label {
  font-size: 12px;
  color: var(--text-secondary);
  font-weight: 600;
}

.btn-tool-sm {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 4px 10px;
  border-radius: 12px;
  font-size: 11px;
  cursor: pointer;
}

/* Modal Overlay */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  z-index: 500;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-card {
  width: 90%;
  max-width: 580px;
  max-height: 80vh;
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6);
}

.modal-header {
  padding: 14px 18px;
  background: var(--bg-input);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h3 {
  font-size: 16px;
  color: #fff;
}

.btn-close-modal {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 16px;
  cursor: pointer;
}

.modal-body {
  padding: 16px 18px;
  overflow-y: auto;
}

.glossary-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.glossary-item {
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-secondary);
}

.glossary-term {
  color: var(--accent-cyan);
}

/* Toast celebration banner */
.celebration-toast {
  position: fixed;
  top: 70px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(15, 23, 42, 0.95);
  border: 2px solid var(--accent-green);
  border-radius: 12px;
  padding: 12px 24px;
  box-shadow: 0 10px 30px rgba(16, 185, 129, 0.4);
  z-index: 999;
  animation: slideDown 0.3s ease;
}

.toast-content {
  display: flex;
  align-items: center;
  gap: 12px;
}

.toast-icon {
  font-size: 28px;
}

#toast-title {
  color: #34d399;
  font-size: 15px;
}

#toast-desc {
  color: var(--text-secondary);
  font-size: 12px;
}

@keyframes slideDown {
  from { top: 30px; opacity: 0; }
  to { top: 70px; opacity: 1; }
}

/* Presentation Mode Fullscreen */
body.presentation-mode .top-header,
body.presentation-mode .side-panel,
body.presentation-mode .bottom-measurement-panel {
  display: none !important;
}

body.presentation-mode .viewport-wrapper {
  width: 100vw;
  height: 100vh;
}

/* Formula Inspector Buttons */
.btn-fx-inspect {
  background: rgba(56, 189, 248, 0.15);
  border: 1px solid rgba(56, 189, 248, 0.4);
  color: #38bdf8;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 11px;
  font-weight: bold;
  padding: 1px 6px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s ease;
  margin-left: auto;
}

.btn-fx-inspect:hover {
  background: rgba(56, 189, 248, 0.35);
  border-color: #38bdf8;
  color: #fff;
  transform: scale(1.05);
}


/* =========================================================
   UNIVERSAL DIRECT KEYBOARD NUMERIC INPUT CONTROLS
   ========================================================= */
.num-input-wrap {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  background: var(--bg-input, #0b1120);
  border: 1px solid var(--border-color, #334155);
  border-radius: 4px;
  padding: 1px 5px;
  transition: all 0.2s ease;
}

.num-input-wrap:focus-within {
  border-color: #38bdf8;
  box-shadow: 0 0 6px rgba(56, 189, 248, 0.4);
}

.param-num-input {
  width: 54px;
  background: transparent;
  border: none;
  outline: none;
  color: #f8fafc;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  font-weight: 700;
  text-align: right;
  -moz-appearance: textfield;
}

.param-num-input::-webkit-outer-spin-button,
.param-num-input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.num-input-wrap .unit {
  font-size: 10px;
  color: #94a3b8;
  font-weight: 600;
}

/* =========================================================
   FULL-SCREEN 2D ACADEMIC CLASSROOM STUDIO (World-Class)
   ========================================================= */
.academic-2d-studio {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 999;
  background: #070b14;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  user-select: none;
}

/* Studio Top Navigation Bar */
.a2d-studio-topbar {
  height: 52px;
  background: #0d1527;
  border-bottom: 1px solid #1e293b;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  flex-shrink: 0;
  gap: 12px;
}

.a2d-brand-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.a2d-badge-pulse {
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.25), rgba(56, 189, 248, 0.15));
  border: 1px solid #0284c7;
  color: #38bdf8;
  font-size: 11px;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 6px;
  letter-spacing: 0.5px;
  box-shadow: 0 0 12px rgba(56, 189, 248, 0.2);
}

.a2d-studio-title {
  font-size: 14px;
  font-weight: 700;
  color: #f1f5f9;
  letter-spacing: 0.2px;
}

/* 4 Graph Display Mode Selectors */
.a2d-mode-selector {
  display: flex;
  background: #070b14;
  padding: 3px;
  border-radius: 8px;
  border: 1px solid #334155;
  gap: 4px;
}

.btn-graph-mode {
  background: transparent;
  border: none;
  color: #94a3b8;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.18s ease;
  display: flex;
  align-items: center;
  gap: 5px;
}

.btn-graph-mode:hover {
  color: #f8fafc;
  background: rgba(51, 65, 85, 0.5);
}

.btn-graph-mode.active {
  background: linear-gradient(135deg, #0284c7, #2563eb);
  color: #fff;
  box-shadow: 0 0 12px rgba(37, 99, 235, 0.5);
}

/* 2D Studio Wave Model Toggle */
.a2d-wave-model-toggle {
  display: flex;
  background: #070b14;
  padding: 3px;
  border-radius: 8px;
  border: 1px solid #334155;
  gap: 3px;
}

.btn-wave-type {
  background: transparent;
  border: none;
  color: #94a3b8;
  padding: 5px 10px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.18s ease;
  display: flex;
  align-items: center;
  gap: 4px;
}

.btn-wave-type:hover {
  color: #f8fafc;
}

.btn-wave-type.active {
  background: linear-gradient(135deg, #10b981, #059669);
  color: #fff;
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.4);
}

/* Axis Range / Direction Selector (অক্ষ বরাবর দিক নির্বাচন) */
.a2d-axis-selector {
  display: flex;
  align-items: center;
  background: #070b14;
  padding: 3px;
  border-radius: 8px;
  border: 1px solid #334155;
  gap: 3px;
}

.axis-lbl {
  font-size: 10px;
  font-weight: 800;
  color: #94a3b8;
  padding: 0 4px;
}

.btn-axis-mode {
  background: transparent;
  border: none;
  color: #94a3b8;
  padding: 5px 9px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.18s ease;
}

.btn-axis-mode:hover {
  color: #f8fafc;
}

.btn-axis-mode.active {
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: #fff;
  box-shadow: 0 0 10px rgba(245, 158, 11, 0.4);
}

.a2d-studio-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.a2d-btn-action {
  background: #1e293b;
  border: 1px solid #475569;
  color: #cbd5e1;
  padding: 5px 12px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
}

.a2d-btn-action:hover {
  background: #334155;
  border-color: #38bdf8;
  color: #fff;
}

.a2d-btn-exit {
  background: rgba(244, 63, 94, 0.2);
  border: 1px solid #f43f5e;
  color: #fca5a5;
  padding: 5px 14px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.15s;
}

.a2d-btn-exit:hover {
  background: #f43f5e;
  color: #fff;
  box-shadow: 0 0 12px rgba(244, 63, 94, 0.5);
}

/* Controls Ribbon (Inputs + Formulas + Phasor) */
.a2d-controls-ribbon {
  background: #090f1d;
  border-bottom: 1px solid #1e293b;
  padding: 10px 16px;
  display: flex;
  gap: 16px;
  flex-shrink: 0;
  align-items: stretch;
}

.a2d-param-console {
  flex: 1.3;
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid #1e293b;
  border-radius: 8px;
  padding: 8px 12px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.console-title {
  font-size: 11px;
  font-weight: 800;
  color: #38bdf8;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
  text-transform: uppercase;
}

.console-inputs-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
}

@media (max-width: 1200px) {
  .console-inputs-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.inp-field-group {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.inp-field-group label {
  font-size: 10px;
  color: #94a3b8;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 3px;
}

.inp-field-group .dot-s1 { color: #38bdf8; }
.inp-field-group .dot-s2 { color: #f43f5e; }

.inp-field-group .input-wrap {
  display: flex;
  align-items: center;
  background: #070b14;
  border: 1px solid #334155;
  border-radius: 4px;
  padding: 2px 5px;
  transition: all 0.15s;
}

.inp-field-group .input-wrap:focus-within {
  border-color: #38bdf8;
  box-shadow: 0 0 6px rgba(56, 189, 248, 0.3);
}

.inp-field-group input {
  width: 100%;
  background: transparent;
  border: none;
  outline: none;
  color: #f8fafc;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  font-weight: 700;
  -moz-appearance: textfield;
}

.inp-field-group input::-webkit-outer-spin-button,
.inp-field-group input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.inp-field-group .u {
  font-size: 9px;
  color: #64748b;
  margin-left: 2px;
}

.inp-field-group.highlight .input-wrap {
  border-color: #fbbf24;
  background: rgba(251, 191, 36, 0.08);
}

.console-quick-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  padding-top: 6px;
  border-top: 1px solid rgba(51, 65, 85, 0.4);
  flex-wrap: wrap;
}

.quick-label {
  font-size: 10px;
  font-weight: 700;
  color: #94a3b8;
  margin-right: 2px;
}

.a2d-btn-snap {
  background: #1e293b;
  border: 1px solid #475569;
  color: #cbd5e1;
  font-size: 10px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.15s;
}

.a2d-btn-snap:hover {
  background: #334155;
  border-color: #fbbf24;
  color: #fef08a;
}

/* Live Formula Blackboard & Phasor */
.a2d-formula-blackboard {
  flex: 1;
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid #1e293b;
  border-radius: 8px;
  padding: 8px 12px;
  display: flex;
  gap: 12px;
  align-items: center;
}

.blackboard-header {
  display: none;
}

.blackboard-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 11px;
}

.calc-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(7, 11, 20, 0.5);
  padding: 2px 8px;
  border-radius: 4px;
  border: 1px solid rgba(51, 65, 85, 0.3);
}

.calc-row .formula {
  color: #94a3b8;
  font-family: monospace;
  font-size: 10px;
}

.calc-row strong {
  color: #38bdf8;
  font-family: monospace;
  font-size: 11px;
}

.condition-chip {
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 10px;
  font-weight: 700;
  text-align: center;
  border: 1px solid;
}

.condition-chip.constructive {
  background: rgba(16, 185, 129, 0.15);
  border-color: #10b981;
  color: #34d399;
}

.condition-chip.destructive {
  background: rgba(244, 63, 94, 0.15);
  border-color: #f43f5e;
  color: #fca5a5;
}

.condition-chip.intermediate {
  background: rgba(251, 191, 36, 0.15);
  border-color: #fbbf24;
  color: #fef08a;
}

/* Phasor Diagram Box */
.phasor-widget-box {
  width: 130px;
  background: #070b14;
  border: 1px solid #334155;
  border-radius: 6px;
  padding: 4px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.phasor-legend {
  font-size: 8px;
  color: #94a3b8;
  margin-top: 2px;
  text-align: center;
}

/* Main Canvas Viewport */
.a2d-canvas-main-viewport {
  flex: 1;
  position: relative;
  width: 100%;
  min-height: 0;
  overflow: hidden;
  background: #070b14;
}

#a2d-studio-canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: crosshair;
}

.a2d-hint-banner {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(51, 65, 85, 0.8);
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 10px;
  color: #94a3b8;
  pointer-events: none;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

.a2d-hint-banner strong {
  color: #38bdf8;
}

/* =========================================================
   PRESENTATION MODE FLOATING EXIT BUTTON
   ========================================================= */
.btn-exit-presentation {
  display: none;
}

body.presentation-mode .btn-exit-presentation {
  display: flex !important;
  align-items: center;
  gap: 8px;
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 10000;
  background: rgba(15, 23, 42, 0.9);
  color: #fb7185;
  border: 1.5px solid #f43f5e;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 4px 24px rgba(244, 63, 94, 0.45);
  backdrop-filter: blur(8px);
  transition: all 0.2s ease;
  animation: pulseExitBtn 2.2s infinite;
}

@keyframes pulseExitBtn {
  0%, 100% { transform: scale(1); box-shadow: 0 4px 20px rgba(244, 63, 94, 0.4); }
  50% { transform: scale(1.03); box-shadow: 0 6px 30px rgba(244, 63, 94, 0.7); }
}

body.presentation-mode .btn-exit-presentation:hover {
  background: #f43f5e;
  color: #ffffff;
}

/* =========================================================
   COLLAPSIBLE & TOGGLEABLE BOTTOM OSCILLOSCOPE PANEL
   ========================================================= */
.bottom-measurement-panel {
  height: 230px;
  transition: height 0.22s cubic-bezier(0.4, 0, 0.2, 1);
}

.bottom-measurement-panel.collapsed {
  height: 38px !important;
}

.bottom-measurement-panel.collapsed .scope-body {
  display: none !important;
}

.bottom-measurement-panel.hidden-panel {
  display: none !important;
}

.banner-right-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
}

.btn-banner-action {
  background: rgba(51, 65, 85, 0.7);
  color: var(--text-secondary);
  border: 1px solid rgba(71, 85, 105, 0.8);
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-banner-action:hover {
  background: rgba(56, 189, 248, 0.2);
  color: var(--accent-cyan);
  border-color: var(--accent-cyan);
}

.chip-btn {
  background: rgba(30, 41, 59, 0.8);
  color: #38bdf8;
  border: 1px solid rgba(56, 189, 248, 0.3);
  padding: 3px 8px;
  border-radius: 4px;
  font-family: monospace;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.15s;
}

.chip-btn:hover {
  background: rgba(56, 189, 248, 0.25);
  border-color: #38bdf8;
}

/* 2D Academic Classroom Custom Equation Strip */
.a2d-custom-eq-banner {
  background: rgba(15, 23, 42, 0.95);
  border-bottom: 1px solid rgba(56, 189, 248, 0.3);
  padding: 7px 16px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  z-index: 10;
  flex-shrink: 0;
}

.a2d-custom-eq-banner .eq-symbol {
  font-family: 'Times New Roman', serif;
  font-size: 16px;
  font-style: italic;
  color: #38bdf8;
  font-weight: bold;
}

.a2d-custom-eq-banner input[type="text"] {
  flex: 1;
  background: #090d16;
  color: #f8fafc;
  border: 1px solid #334155;
  padding: 5px 10px;
  border-radius: 4px;
  font-family: monospace;
  font-size: 13px;
  outline: none;
}

.a2d-custom-eq-banner input[type="text"]:focus {
  border-color: #38bdf8;
}

.a2d-custom-eq-banner select {
  background: #1e293b;
  color: #e2e8f0;
  border: 1px solid #334155;
  padding: 5px 8px;
  border-radius: 4px;
  font-size: 12px;
  outline: none;
  max-width: 250px;
}

.btn-eq-apply {
  background: #0284c7;
  color: #ffffff;
  border: none;
  padding: 5px 12px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
}

.btn-eq-apply:hover {
  background: #0369a1;
}

.btn-eq-toggle {
  background: rgba(244, 63, 94, 0.15);
  color: #fb7185;
  border: 1px solid rgba(244, 63, 94, 0.4);
  padding: 5px 10px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: bold;
  cursor: pointer;
  white-space: nowrap;
}

.btn-eq-toggle.active {
  background: rgba(52, 211, 153, 0.2);
  color: #34d399;
  border-color: rgba(52, 211, 153, 0.5);
}

.eq-status-pill {
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 4px;
  display: none;
}
.eq-status-pill.error {
  display: inline-block;
  background: rgba(244, 63, 94, 0.2);
  color: #fb7185;
}
.eq-status-pill.active {
  display: inline-block;
  background: rgba(52, 211, 153, 0.2);
  color: #34d399;
}

/* =========================================================
   2D CLASSROOM WAVE MOTION NATURE & FEATURE CONTROLS
   ========================================================= */
.a2d-motion-selector {
  display: flex;
  background: #070b14;
  padding: 3px;
  border-radius: 8px;
  border: 1px solid #334155;
  gap: 3px;
}

.btn-motion-mode {
  background: transparent;
  border: none;
  color: #94a3b8;
  padding: 5px 11px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.18s ease;
  display: flex;
  align-items: center;
  gap: 5px;
  white-space: nowrap;
}

.btn-motion-mode:hover {
  color: #f8fafc;
  background: rgba(51, 65, 85, 0.5);
}

.btn-motion-mode.active {
  background: linear-gradient(135deg, #059669, #10b981);
  color: #fff;
  box-shadow: 0 0 12px rgba(16, 185, 129, 0.45);
}

.a2d-feature-toggles {
  display: flex;
  background: #070b14;
  padding: 3px;
  border-radius: 8px;
  border: 1px solid #334155;
  gap: 3px;
}

.btn-feat-toggle {
  background: transparent;
  border: 1px solid transparent;
  color: #94a3b8;
  padding: 4px 9px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.btn-feat-toggle:hover {
  color: #f8fafc;
  background: rgba(51, 65, 85, 0.4);
}

.btn-feat-toggle.active {
  background: rgba(245, 158, 11, 0.2);
  color: #fbbf24;
  border-color: rgba(245, 158, 11, 0.4);
}

/* =========================================================
   MOBILE RESPONSIVENESS & PWA DRAWER NAVIGATION (<= 900px)
   ========================================================= */

/* Mobile Bottom Floating Quick Dock */
.mobile-bottom-dock {
  display: none;
  position: fixed;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  background: rgba(15, 23, 42, 0.92);
  border: 1px solid rgba(56, 189, 248, 0.4);
  border-radius: 24px;
  padding: 4px 8px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(12px);
  gap: 6px;
}

.btn-mobile-pill {
  background: transparent;
  border: none;
  color: #e2e8f0;
  padding: 6px 14px;
  border-radius: 18px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 5px;
  transition: all 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}

.btn-mobile-pill:active,
.btn-mobile-pill.active {
  background: #0284c7;
  color: #ffffff;
}

/* Mobile Drawer Backdrop */
.mobile-drawer-backdrop {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.65);
  z-index: 998;
  backdrop-filter: blur(3px);
  transition: opacity 0.25s ease;
}

.mobile-drawer-backdrop.active {
  display: block;
}

@media (max-width: 900px) {
  /* Show mobile quick dock */
  .mobile-bottom-dock {
    display: flex;
  }

  /* Top navigation: smooth horizontal scroll on mobile */
  .top-header {
    overflow-x: auto;
    overflow-y: hidden;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
    padding: 6px 10px;
    gap: 8px;
    scrollbar-width: none;
  }

  .top-header::-webkit-scrollbar {
    display: none;
  }

  .brand h1 {
    font-size: 13px;
  }

  /* Side panels become off-canvas slide-in drawers */
  .main-content-layout {
    position: relative;
    overflow: hidden;
    width: 100vw;
  }

  .side-panel {
    position: fixed;
    top: 52px;
    bottom: 0;
    width: 320px;
    max-width: 86vw;
    z-index: 999;
    box-shadow: 0 0 35px rgba(0, 0, 0, 0.85);
    transition: transform 0.28s cubic-bezier(0.4, 0, 0.2, 1);
    background: #0f172a;
  }

  #left-panel {
    left: 0;
    transform: translateX(-105%);
    border-right: 1px solid rgba(56, 189, 248, 0.3);
  }

  #left-panel.mobile-open {
    transform: translateX(0);
  }

  .right-panel {
    right: 0;
    transform: translateX(105%);
    border-left: 1px solid rgba(56, 189, 248, 0.3);
  }

  .right-panel.mobile-open {
    transform: translateX(0);
  }

  /* 3D Viewport takes full 100% width on mobile */
  .viewport-wrapper {
    width: 100vw;
    flex: 1;
  }

  /* Bottom Oscilloscope collapses by default on mobile screens */
  .bottom-measurement-panel {
    height: 38px;
  }

  .bottom-measurement-panel:not(.expanded-mobile) .scope-body {
    display: none;
  }

  .bottom-measurement-panel.expanded-mobile {
    height: 220px;
  }

  .measurements-banner {
    overflow-x: auto;
    scrollbar-width: none;
  }

  /* 2D Classroom Studio Mobile Layout */
  .a2d-studio-topbar {
    overflow-x: auto;
    scrollbar-width: none;
    padding: 6px 10px;
    gap: 6px;
  }

  .a2d-controls-ribbon {
    flex-direction: column;
    max-height: 48vh;
    overflow-y: auto;
  }

  .a2d-param-console {
    width: 100%;
  }

  .a2d-formula-blackboard {
    width: 100%;
  }

  .console-inputs-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* Prevent iOS automatic zoom on inputs */
  input[type="number"],
  input[type="text"],
  select {
    font-size: 15px !important;
  }
}