/* ============================================================
   4-to-2 Encoder Virtual Laboratory — Style Sheet
   Virtual Instrumentation Labs Interactive Learning Platform
   ============================================================ */

/* ── Reset & Base Styles ────────────────────────────────────── */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Laboratory Colour Palette */
  --lab-bg:           #ffffff;
  --panel-bg:         #f8fafc;
  --panel-border:     #cbd5e1;
  --header-bg:        #0f172a;
  --header-text:      #ffffff;
  --accent:           #2563eb;
  --accent-hover:     #1d4ed8;
  --accent-light:     #dbeafe;
  --text-primary:     #0f172a;
  --text-secondary:   #475569;
  --text-muted:       #94a3b8;
  
  /* Signal & Wire Colors */
  --wire-off:         #94a3b8;
  --wire-on:          #2563eb;
  --wire-on-glow:     rgba(37, 99, 235, 0.4);
  --signal-high:      #2563eb;
  --signal-low:       #64748b;
  --wire-invalid:     #ef4444;
  
  /* Accent distinction */
  --input-accent-bg:  #f1f5f9;
  --input-accent:     #3b82f6;

  /* Output / LED Colors */
  --led-off-bg:       #475569;
  --led-off-border:   #334155;
  --led-on-bg:        #10b981;
  --led-on-border:    #059669;
  --led-on-glow:      0 0 14px rgba(16, 185, 129, 0.7);

  --danger-bg:        #fef2f2;
  --danger-border:    #fca5a5;
  --danger-text:      #dc2626;

  --success:          #16a34a;
  --success-bg:       #dcfce7;
  --success-border:   #86efac;
  
  --gate-fill:        #f1f5f9;
  --gate-stroke:      #1e293b;
  --gate-active-fill: #eff6ff;
  --gate-active-stroke:#2563eb;
  
  --shadow-sm:        0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md:        0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg:        0 10px 25px rgba(0, 0, 0, 0.1);
  
  --radius-sm:        4px;
  --radius-md:        8px;
  --radius-lg:        12px;
  
  --font-sans:        'Segoe UI', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono:        'Cascadia Code', 'Fira Code', 'Consolas', monospace;
}

html {
  font-size: 15px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--lab-bg);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ── Laboratory Title Bar ──────────────────────────────────── */
.lab-title-bar {
  background: var(--header-bg);
  color: var(--header-text);
  padding: 16px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 10px rgba(0,0,0,0.25);
}

.lab-title-container h1 {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.3px;
}

.lab-title-bar .lab-subtitle {
  font-size: 0.8rem;
  color: #94a3b8;
  font-weight: 400;
  display: block;
}

.lab-badge {
  background: var(--accent);
  color: #fff;
  font-size: 0.72rem;
  padding: 4px 12px;
  border-radius: 12px;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

/* ── Main Layout Container ─────────────────────────────────── */
.lab-main {
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px 20px 48px;
  display: flex;
  flex-direction: column;
  gap: 24px;
  width: 100%;
  flex: 1;
}

/* ── Toolbar & Control Bar ─────────────────────────────────── */
.lab-toolbar {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-lg);
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  box-shadow: var(--shadow-sm);
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.toolbar-label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-secondary);
  letter-spacing: 0.5px;
}

.toolbar-divider {
  width: 1px;
  height: 28px;
  background: var(--panel-border);
}

/* Button Component Styles */
.btn {
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
  user-select: none;
}

.btn .icon {
  font-size: 1rem;
}

.btn--mode {
  background: #ffffff;
  border-color: var(--panel-border);
  color: var(--text-secondary);
}

.btn--mode:hover {
  background: #f1f5f9;
  color: var(--text-primary);
}

.btn--mode.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #ffffff;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.3);
}

.btn--secondary {
  background: #ffffff;
  border-color: var(--panel-border);
  color: var(--text-primary);
}

.btn--secondary:hover:not(:disabled) {
  background: #f1f5f9;
  border-color: #94a3b8;
}

.btn--secondary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn--outline {
  background: transparent;
  border-color: #cbd5e1;
  color: var(--text-secondary);
}

.btn--outline:hover {
  background: #fee2e2;
  border-color: #f87171;
  color: #dc2626;
}

.btn--accent {
  background: #0f172a;
  color: #ffffff;
}

.btn--accent:hover {
  background: #1e293b;
}

.btn--danger {
  background: #ef4444;
  color: #ffffff;
}

.btn--danger:hover {
  background: #dc2626;
}

/* ── Generic Panel Container ────────────────────────────────── */
.lab-panel {
  background: #ffffff;
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.lab-panel__header {
  background: var(--panel-bg);
  border-bottom: 1px solid var(--panel-border);
  padding: 12px 20px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.lab-panel__body {
  padding: 20px;
}

/* ── Top Grid: Input Controls & Output Monitor ───────────────── */
.lab-top-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

@media (max-width: 900px) {
  .lab-top-grid {
    grid-template-columns: 1fr;
  }
}

/* Input Section Titles */
.input-section-title {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 12px;
}

.inputs-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

@media (max-width: 500px) {
  .inputs-grid {
    grid-template-columns: 1fr;
  }
}

/* Input Card Component */
.input-control-card {
  background: #ffffff;
  border: 1.5px solid var(--panel-border);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: all 0.2s ease;
}

.input-control-card.active {
  border-color: var(--accent);
  background: #eff6ff;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.15);
}

.input-control-card.invalid-state {
  border-color: #f87171;
  background: #fef2f2;
}

.input-meta {
  display: flex;
  flex-direction: column;
}

.input-symbol {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-primary);
}

.input-role {
  font-size: 0.72rem;
  color: var(--text-secondary);
}

/* Toggle Switch Component */
.toggle-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 2px;
  user-select: none;
}

.toggle-btn__track {
  width: 44px;
  height: 24px;
  background: #cbd5e1;
  border-radius: 12px;
  position: relative;
  transition: background-color 0.2s ease;
}

.toggle-btn__knob {
  width: 18px;
  height: 18px;
  background: #ffffff;
  border-radius: 50%;
  position: absolute;
  top: 3px;
  left: 3px;
  transition: transform 0.2s ease;
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.toggle-btn.high .toggle-btn__track {
  background: var(--accent);
}

.toggle-btn.high .toggle-btn__knob {
  transform: translateX(20px);
}

.toggle-btn__state {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.95rem;
  min-width: 16px;
  text-align: center;
  color: var(--text-secondary);
}

.toggle-btn.high .toggle-btn__state {
  color: var(--accent);
}

/* ── Output Monitor Panel ───────────────────────────────────── */
.output-body {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.badge-row-active {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 10px;
  background: #dbeafe;
  color: #1e40af;
  letter-spacing: 0.5px;
}

/* Banner Displays */
.output-banners-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

@media (max-width: 500px) {
  .output-banners-container {
    grid-template-columns: 1fr;
  }
}

.encoded-display-banner {
  background: #0f172a;
  color: #ffffff;
  border-radius: var(--radius-md);
  padding: 14px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.encoded-display-banner.invalid {
  background: #7f1d1d;
  border: 1px solid #f87171;
}

.encoded-display-banner .banner-title {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: #94a3b8;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.encoded-display-banner .banner-value {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  font-weight: 800;
  color: #60a5fa;
  letter-spacing: 4px;
  line-height: 1;
  margin: 4px 0;
}

.encoded-display-banner.invalid .banner-value {
  color: #fca5a5;
  font-size: 1.4rem;
  letter-spacing: 1px;
}

.encoded-display-banner .banner-subtext {
  font-size: 0.78rem;
  color: #cbd5e1;
}

/* Invalid Warning Banner */
.invalid-warning-box {
  background: var(--danger-bg);
  border: 1px solid var(--danger-border);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  animation: fadeIn 0.3s ease-in-out;
}

.invalid-warning-content {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--danger-text);
  font-size: 0.85rem;
  font-weight: 600;
}

.invalid-warning-content .warning-icon {
  font-size: 1.4rem;
}

/* Outputs LED Grid */
.outputs-led-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.led-card {
  background: #ffffff;
  border: 1.5px solid var(--panel-border);
  border-radius: var(--radius-md);
  padding: 12px;
  display: flex;
  align-items: center;
  gap: 14px;
  transition: all 0.2s ease;
}

.led-card.active-led {
  border-color: var(--success-border);
  background: var(--success-bg);
}

.led-card.invalid-led {
  border-color: var(--danger-border);
  background: var(--danger-bg);
}

.led-indicator-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
}

.led-light {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--led-off-bg);
  border: 2px solid var(--led-off-border);
  transition: all 0.3s ease;
}

.led-light.active {
  background: var(--led-on-bg);
  border-color: var(--led-on-border);
  box-shadow: var(--led-on-glow);
}

.led-light.invalid {
  background: #ef4444;
  border-color: #b91c1c;
  box-shadow: 0 0 14px rgba(239, 68, 68, 0.7);
}

.led-info {
  display: flex;
  flex-direction: column;
}

.led-name {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1rem;
  color: var(--text-primary);
}

.led-expr {
  font-size: 0.73rem;
  color: var(--text-secondary);
  font-family: var(--font-mono);
}

.led-state-badge {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  display: inline-block;
  margin-top: 2px;
  width: fit-content;
}

.led-state-badge.high {
  background: #dcfce7;
  color: #15803d;
}

.led-state-badge.low {
  background: #f1f5f9;
  color: #64748b;
}

.led-state-badge.invalid {
  background: #fee2e2;
  color: #b91c1c;
}

/* ── Schematic Diagram Panel ────────────────────────────────── */
.schematic-panel {
  position: relative;
}

.schematic-wrapper {
  position: relative;
  width: 100%;
  overflow-x: auto;
  background: #ffffff;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.schematic-svg {
  width: 100%;
  min-width: 750px;
  height: auto;
  display: block;
  user-select: none;
}

/* SVG Wires & Gates Styling */
.wire {
  stroke: var(--wire-off);
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  transition: stroke 0.25s ease, stroke-width 0.25s ease;
}

.wire.active {
  stroke: var(--wire-on);
  stroke-width: 3.5;
  filter: drop-shadow(0 0 3px var(--wire-on-glow));
}

.wire.invalid {
  stroke: var(--wire-invalid);
  stroke-width: 3.5;
}

.wire-label {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  fill: var(--text-secondary);
}

.wire-val {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 800;
  fill: var(--text-secondary);
}

.wire-val.active {
  fill: var(--accent);
}

.wire-val.invalid {
  fill: var(--wire-invalid);
}

.gate-body {
  fill: var(--gate-fill);
  stroke: var(--gate-stroke);
  stroke-width: 2;
  transition: all 0.3s ease;
}

.gate-body.active {
  fill: var(--gate-active-fill);
  stroke: var(--gate-active-stroke);
  stroke-width: 2.5;
}

.gate-label {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  fill: var(--text-primary);
  text-anchor: middle;
}

.gate-sublabel {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  fill: var(--text-secondary);
  text-anchor: middle;
}

.junction-dot {
  fill: var(--wire-off);
  transition: fill 0.25s ease;
}

.junction-dot.active {
  fill: var(--wire-on);
}

/* Signal Flow Pulse Dot Animation */
.pulse-dot {
  fill: #60a5fa;
  r: 5;
  filter: drop-shadow(0 0 6px #2563eb);
  opacity: 0;
}

.pulse-dot.animating {
  opacity: 1;
}

/* IC Block Styling */
.ic-box {
  fill: #1e293b;
  stroke: #0f172a;
  stroke-width: 3;
  rx: 8;
}

.ic-title {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 800;
  fill: #ffffff;
  text-anchor: middle;
}

.ic-subtitle {
  font-family: var(--font-sans);
  font-size: 11px;
  fill: #94a3b8;
  text-anchor: middle;
}

.ic-pin-label {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  fill: #cbd5e1;
}

/* ── Evaluation Logic Breakdown Panel ───────────────────────── */
.eval-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 16px;
}

@media (max-width: 700px) {
  .eval-grid {
    grid-template-columns: 1fr;
  }
}

.eval-card {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-md);
  padding: 14px 16px;
}

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

.eval-card__title {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.eval-card__calc {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-secondary);
  background: #ffffff;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid #e2e8f0;
}

.eval-summary-box {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-md);
  padding: 12px 16px;
  font-size: 0.88rem;
  color: #1e40af;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.eval-summary-box .info-icon {
  font-size: 1.1rem;
}

/* ── Truth Table Panel ──────────────────────────────────────── */
.truth-table-container {
  overflow-x: auto;
}

.truth-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  text-align: center;
}

.truth-table th {
  background: var(--header-bg);
  color: #ffffff;
  padding: 10px 14px;
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.5px;
  border: 1px solid #334155;
}

.truth-table td {
  padding: 10px 14px;
  border: 1px solid var(--panel-border);
  color: var(--text-primary);
  transition: background-color 0.2s ease;
}

.truth-table tr:nth-child(even) td {
  background: #f8fafc;
}

.truth-table tr.active-row td {
  background: #dbeafe !important;
  color: #1e40af;
  font-weight: 700;
}

.truth-table tr.active-row td:first-child {
  border-left: 4px solid var(--accent);
}

.truth-table .badge-row-active-tag {
  background: var(--accent);
  color: #ffffff;
  font-size: 0.7rem;
  padding: 2px 6px;
  border-radius: 4px;
  margin-left: 6px;
}

.truth-table-note {
  margin-top: 14px;
  padding: 10px 14px;
  background: var(--panel-bg);
  border-left: 4px solid var(--accent);
  font-size: 0.82rem;
  color: var(--text-secondary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* ── Theory & Educational Panels ───────────────────────────── */
.educational-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

@media (max-width: 900px) {
  .educational-grid {
    grid-template-columns: 1fr;
  }
}

.theory-card {
  background: #ffffff;
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.theory-card__header {
  background: var(--panel-bg);
  border-bottom: 1px solid var(--panel-border);
  padding: 12px 18px;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.theory-card__body {
  padding: 18px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.theory-card__body h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 12px 0 6px;
}

.theory-card__body h4:first-child {
  margin-top: 0;
}

.theory-card__body ul {
  padding-left: 20px;
  margin-bottom: 12px;
}

.theory-card__body li {
  margin-bottom: 4px;
}

.theory-card__body p {
  margin-bottom: 12px;
}

.equation-box {
  background: var(--panel-bg);
  border: 1px dashed var(--panel-border);
  border-radius: var(--radius-md);
  padding: 12px;
  margin: 10px 0;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--text-primary);
  text-align: center;
  font-size: 1rem;
}

/* Comparison Table */
.comp-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
  font-size: 0.85rem;
}

.comp-table th, .comp-table td {
  padding: 8px 12px;
  border: 1px solid var(--panel-border);
  text-align: left;
}

.comp-table th {
  background: #f1f5f9;
  font-weight: 700;
  color: var(--text-primary);
}

/* ── Lab Footer ────────────────────────────────────────────── */
.lab-footer {
  background: var(--header-bg);
  color: #94a3b8;
  text-align: center;
  padding: 16px;
  font-size: 0.8rem;
  margin-top: auto;
}

.lab-footer a {
  color: #60a5fa;
  text-decoration: none;
}

.lab-footer a:hover {
  text-decoration: underline;
}

/* Keyframes & Utility Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ── Dark Theme Overrides ───────────────────────────────────── */
[data-theme="dark"] {
  --lab-bg:           #0f172a;
  --panel-bg:         #1e293b;
  --panel-border:     #334155;
  --header-bg:        #020617;
  --header-text:      #f1f5f9;
  --accent:           #3b82f6;
  --accent-hover:     #60a5fa;
  --accent-light:     #1e3a5f;
  --text-primary:     #f1f5f9;
  --text-secondary:   #94a3b8;
  --text-muted:       #64748b;

  --wire-off:         #475569;
  --wire-on:          #60a5fa;
  --wire-on-glow:     rgba(96, 165, 250, 0.4);
  --signal-high:      #60a5fa;
  --signal-low:       #475569;
  --wire-invalid:     #f87171;

  --input-accent-bg:  #1e293b;
  --input-accent:     #3b82f6;

  --led-off-bg:       #334155;
  --led-off-border:   #475569;
  --led-on-bg:        #10b981;
  --led-on-border:    #059669;
  --led-on-glow:      0 0 14px rgba(16, 185, 129, 0.7);

  --danger-bg:        #3b0f0f;
  --danger-border:    #7f1d1d;
  --danger-text:      #fca5a5;

  --success:          #10b981;
  --success-bg:       #052e16;
  --success-border:   #166534;

  --gate-fill:        #1e293b;
  --gate-stroke:      #cbd5e1;
  --gate-active-fill: #1e3a5f;
  --gate-active-stroke:#60a5fa;

  --shadow-sm:        0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md:        0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg:        0 10px 25px rgba(0, 0, 0, 0.5);
}

/* Dark: body & general backgrounds */
[data-theme="dark"] body {
  background: var(--lab-bg);
  color: var(--text-primary);
}

/* Dark: panels */
[data-theme="dark"] .lab-panel {
  background: #1e293b;
  border-color: var(--panel-border);
}

[data-theme="dark"] .lab-toolbar {
  background: #1e293b;
  border-color: var(--panel-border);
}

/* Dark: buttons */
[data-theme="dark"] .btn--mode,
[data-theme="dark"] .btn--secondary {
  background: #1e293b;
  border-color: var(--panel-border);
  color: var(--text-secondary);
}

[data-theme="dark"] .btn--mode:hover,
[data-theme="dark"] .btn--secondary:hover:not(:disabled) {
  background: #334155;
  color: var(--text-primary);
}

[data-theme="dark"] .btn--mode.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #ffffff;
}

/* Dark: input cards */
[data-theme="dark"] .input-control-card {
  background: #1e293b;
  border-color: var(--panel-border);
}

[data-theme="dark"] .input-control-card.active {
  background: #1e3a5f;
  border-color: var(--accent);
}

[data-theme="dark"] .input-control-card.invalid-state {
  background: #3b0f0f;
  border-color: #f87171;
}

/* Dark: toggle track */
[data-theme="dark"] .toggle-btn__track {
  background: #475569;
}

/* Dark: LED cards */
[data-theme="dark"] .led-card {
  background: #1e293b;
  border-color: var(--panel-border);
}

[data-theme="dark"] .led-card.active-led {
  background: #052e16;
  border-color: #166534;
}

[data-theme="dark"] .led-card.invalid-led {
  background: #3b0f0f;
  border-color: #7f1d1d;
}

/* Dark: led state badges */
[data-theme="dark"] .led-state-badge.high {
  background: #052e16;
  color: #4ade80;
}

[data-theme="dark"] .led-state-badge.low {
  background: #1e293b;
  color: #94a3b8;
}

[data-theme="dark"] .led-state-badge.invalid {
  background: #3b0f0f;
  color: #fca5a5;
}

/* Dark: schematic & SVG wrappers */
[data-theme="dark"] .schematic-wrapper {
  background: #0f172a;
}

/* Dark: eval cards */
[data-theme="dark"] .eval-card {
  background: #1e293b;
  border-color: var(--panel-border);
}

[data-theme="dark"] .eval-card__calc {
  background: #0f172a;
  border-color: #334155;
  color: var(--text-secondary);
}

[data-theme="dark"] .eval-summary-box {
  background: #1e3a5f;
  border-color: #2563eb;
  color: #93c5fd;
}

/* Dark: truth table */
[data-theme="dark"] .truth-table th {
  background: #020617;
  border-color: #334155;
}

[data-theme="dark"] .truth-table td {
  border-color: var(--panel-border);
  color: var(--text-primary);
}

[data-theme="dark"] .truth-table tr:nth-child(even) td {
  background: #1e293b;
}

[data-theme="dark"] .truth-table tr.active-row td {
  background: #1e3a5f !important;
  color: #93c5fd;
}

[data-theme="dark"] .truth-table-note {
  background: #1e293b;
  color: var(--text-secondary);
}

/* Dark: theory cards */
[data-theme="dark"] .theory-card {
  background: #1e293b;
  border-color: var(--panel-border);
}

[data-theme="dark"] .theory-card__body {
  color: var(--text-secondary);
}

[data-theme="dark"] .theory-card__body h4 {
  color: var(--text-primary);
}

[data-theme="dark"] .equation-box {
  background: #0f172a;
  border-color: #334155;
  color: var(--text-primary);
}

/* Dark: comparison table */
[data-theme="dark"] .comp-table th {
  background: #334155;
  color: var(--text-primary);
}

[data-theme="dark"] .comp-table td {
  border-color: var(--panel-border);
  color: var(--text-secondary);
}

/* Dark: badge row active */
[data-theme="dark"] .badge-row-active {
  background: #1e3a5f;
  color: #93c5fd;
}

/* Dark: invalid warning */
[data-theme="dark"] .invalid-warning-box {
  background: #3b0f0f;
  border-color: #7f1d1d;
}

[data-theme="dark"] .invalid-warning-content {
  color: #fca5a5;
}