/* ==========================================================================
   Camera Essentials Guide — Styles
   Visual, interactive reference guide for DSLR/Mirrorless cameras
   ========================================================================== */

/* --------------------------------------------------------------------------
   Fonts & Base
   -------------------------------------------------------------------------- */
.guide-page {
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;
  
  /* Guide-specific accent colors */
  --color-aperture: #6366f1;
  --color-shutter: #f59e0b;
  --color-iso: #10b981;
  --color-focus: #ec4899;
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.9em;
}

/* --------------------------------------------------------------------------
   Guide Page — Section Padding Override
   The guide sections use slightly more padding for visual breathing room
   -------------------------------------------------------------------------- */
.guide-page .ref-section {
  padding: var(--space-16) 0;
}

/* --------------------------------------------------------------------------
   Exposure Triangle — Interactive Simulator
   -------------------------------------------------------------------------- */
.exposure-simulator {
  position: relative;
  width: 100%;
  max-width: 800px;
  height: 520px;
  margin: 0 auto var(--space-8);
}

@media (max-width: 768px) {
  .exposure-simulator {
    height: auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
    padding: var(--space-4);
  }
}

/* Central Exposure Meter */
.exposure-center {
  position: absolute;
  top: 55%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  z-index: 2;
}

@media (max-width: 768px) {
  .exposure-center {
    position: relative;
    top: auto;
    left: auto;
    transform: none;
    order: -1;
  }
}

.exposure-meter-ring {
  position: relative;
  width: 100px;
  height: 100px;
}

.exposure-meter-ring svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

#exposure-arc {
  transition: stroke-dashoffset 0.4s ease, stroke 0.3s ease;
}

.exposure-meter-center {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.meter-value {
  font-size: var(--text-2xl);
  font-weight: var(--font-weight-bold);
  font-family: var(--font-mono);
  line-height: 1;
  transition: color 0.3s ease;
}

.meter-label {
  font-size: 10px;
  color: var(--color-gray-500);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
}

.exposure-status {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-600);
  transition: color 0.3s ease;
  white-space: nowrap;
}

.exposure-status[data-status="under"] { color: #1a1a1a; }
.exposure-status[data-status="over"] { color: #1a1a1a; }
.exposure-status[data-status="balanced"] { color: var(--color-gray-500); }

/* Triangle Connections */
.triangle-connections {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

@media (max-width: 768px) {
  .triangle-connections {
    display: none;
  }
}

/* Triangle Controls */
.triangle-control {
  position: absolute;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-4);
  background: var(--color-white);
  border: 2px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.triangle-control:hover {
  box-shadow: var(--shadow-lg);
}

@media (max-width: 768px) {
  .triangle-control {
    position: relative;
    width: 100%;
    justify-content: space-between;
  }
}

.triangle-control--aperture {
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  flex-direction: row;
}

.triangle-control--shutter {
  bottom: 60px;
  left: 0;
  flex-direction: row;
}

.triangle-control--iso {
  bottom: 60px;
  right: 0;
  flex-direction: row;
}

@media (max-width: 768px) {
  .triangle-control--aperture,
  .triangle-control--shutter,
  .triangle-control--iso {
    position: relative;
    top: auto;
    left: auto;
    right: auto;
    bottom: auto;
    transform: none;
  }
}

/* Control buttons */
.control-btn {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-lg);
  font-weight: var(--font-weight-medium);
  background: var(--color-gray-100);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
  flex-shrink: 0;
}

.control-btn:hover {
  background: var(--color-black);
  color: white;
  border-color: var(--color-black);
}

.control-btn:active {
  transform: scale(0.95);
}

/* Control display */
.control-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 70px;
  padding: 0 var(--space-2);
}

@media (max-width: 768px) {
  .control-display {
    flex: 1;
  }
}

.control-value {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-bold);
  font-family: var(--font-mono);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.control-label {
  font-size: 10px;
  color: var(--color-gray-500);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
}

.control-stops {
  font-size: 10px;
  font-family: var(--font-mono);
  color: var(--color-gray-400);
  margin-top: 1px;
  transition: color 0.3s ease;
}

.control-stops[data-direction="positive"] {
  color: var(--color-black);
}

.control-stops[data-direction="negative"] {
  color: var(--color-black);
}

/* Effect bar */
.control-effect {
  width: 90px;
  padding-left: var(--space-3);
  margin-left: var(--space-2);
  border-left: 1px solid var(--color-gray-100);
}

.effect-label {
  display: block;
  font-size: 10px;
  color: var(--color-gray-500);
  margin-bottom: 4px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.effect-bar {
  height: 4px;
  background: var(--color-gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.effect-fill {
  height: 100%;
  background: var(--color-black);
  border-radius: var(--radius-full);
  transition: width 0.3s ease;
  width: 30%;
}

.effect-range {
  display: flex;
  justify-content: space-between;
  font-size: 9px;
  color: var(--color-gray-400);
  margin-top: 2px;
}

/* Exposure Preview Strip */
.exposure-preview {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  width: 180px;
  height: 20px;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-gray-200);
}

@media (max-width: 768px) {
  .exposure-preview {
    position: relative;
    bottom: auto;
    left: auto;
    transform: none;
    width: 100%;
    margin-top: var(--space-4);
  }
}

.preview-gradient {
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, #000 0%, #555 25%, #999 50%, #ccc 75%, #fff 100%);
}

.preview-indicator {
  position: absolute;
  top: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: calc(100% + 4px);
  background: var(--color-black);
  box-shadow: 0 0 0 1px white;
  transition: left 0.3s ease;
}

/* Triangle Actions */
.triangle-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-6);
  margin-bottom: var(--space-10);
  flex-wrap: wrap;
}

.action-btn {
  padding: var(--space-2) var(--space-5);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  background: var(--color-white);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.action-btn:hover {
  background: var(--color-black);
  color: white;
  border-color: var(--color-black);
}

.action-hint {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-gray-500);
}

.hint-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: var(--color-gray-100);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
}

/* Equivalent Exposures */
.equivalent-exposures {
  padding: var(--space-6);
  background: var(--color-gray-50);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
}

.equiv-title {
  font-size: var(--text-base);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-1);
}

.equiv-subtitle {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
  margin-bottom: var(--space-5);
}

.equiv-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-3);
}

.equiv-card {
  display: flex;
  flex-direction: column;
  padding: var(--space-3);
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.equiv-card:hover {
  border-color: var(--color-black);
  box-shadow: var(--shadow-sm);
}

.equiv-card.active {
  border-color: var(--color-black);
  background: var(--color-black);
  color: white;
}

.equiv-values {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  margin-bottom: var(--space-2);
}

.equiv-card.active .equiv-values {
  color: white;
}

.equiv-effects {
  display: flex;
  gap: var(--space-2);
}

.equiv-effect {
  font-size: 10px;
  padding: 2px 6px;
  background: var(--color-gray-100);
  border-radius: var(--radius-sm);
  color: var(--color-gray-600);
}

.equiv-card.active .equiv-effect {
  background: rgba(255,255,255,0.2);
  color: rgba(255,255,255,0.8);
}

/* --------------------------------------------------------------------------
   Aperture Section
   -------------------------------------------------------------------------- */
.aperture-demo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-10);
}

@media (max-width: 768px) {
  .aperture-demo {
    grid-template-columns: 1fr;
  }
}

.aperture-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-6);
}

/* Realistic Aperture Assembly */
.aperture-assembly {
  position: relative;
  width: 260px;
  height: 260px;
}

.lens-barrel {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  pointer-events: none;
}

.barrel-ring {
  position: absolute;
  border-radius: 50%;
}

.barrel-ring--outer {
  inset: 0;
  background: linear-gradient(145deg, #2a2a2a 0%, #1a1a1a 50%, #252525 100%);
  box-shadow: 
    inset 0 2px 4px rgba(255,255,255,0.1),
    inset 0 -2px 4px rgba(0,0,0,0.3),
    0 4px 20px rgba(0,0,0,0.5),
    0 8px 40px rgba(0,0,0,0.3);
}

.barrel-ring--inner {
  inset: 8px;
  background: linear-gradient(145deg, #1f1f1f 0%, #141414 100%);
  box-shadow: 
    inset 0 1px 2px rgba(255,255,255,0.05),
    inset 0 -1px 2px rgba(0,0,0,0.5);
}

.aperture-iris {
  position: absolute;
  inset: 12px;
  width: calc(100% - 24px);
  height: calc(100% - 24px);
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.3));
}

/* Iris blade styling - 3-color cycle for 9 blades */
.iris-blade {
  stroke: #3a3a3a;
  stroke-width: 0.5;
  transition: d 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  filter: drop-shadow(1px 1px 1px rgba(0,0,0,0.3));
}

/* Three-shade cycle ensures no adjacent blades share the same color */
.iris-blade:nth-child(3n+1) {
  fill: #1a1a1a;
}

.iris-blade:nth-child(3n+2) {
  fill: #2a2a2a;
}

.iris-blade:nth-child(3n+3) {
  fill: #222222;
}

.iris-opening {
  transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  filter: drop-shadow(0 0 8px rgba(120, 180, 220, 0.3));
}

.glass-reflection {
  transition: all 0.4s ease;
  pointer-events: none;
}

/* F-stop display */
.fstop-display {
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-black);
  color: white;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-md);
}

.fstop-current {
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  font-weight: var(--font-weight-bold);
  letter-spacing: -0.02em;
}

/* Aperture control ring */
.aperture-controls {
  width: 100%;
  max-width: 300px;
}

.aperture-ring {
  position: relative;
  margin-bottom: var(--space-2);
}

.ring-track {
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 6px;
  transform: translateY(-50%);
  background: linear-gradient(90deg, 
    #1a1a1a 0%, 
    #2a2a2a 20%,
    #333 50%,
    #2a2a2a 80%,
    #1a1a1a 100%
  );
  border-radius: var(--radius-full);
  box-shadow: 
    inset 0 1px 3px rgba(0,0,0,0.5),
    0 1px 0 rgba(255,255,255,0.1);
  pointer-events: none;
}

.ring-indicator {
  position: absolute;
  top: 50%;
  left: 33%;
  transform: translate(-50%, -50%);
  width: 4px;
  height: 4px;
  background: var(--color-aperture);
  border-radius: 50%;
  box-shadow: 0 0 6px var(--color-aperture);
  transition: left 0.15s ease;
}

.aperture-slider,
.shutter-slider,
.iso-slider {
  width: 100%;
  height: 24px;
  appearance: none;
  background: transparent;
  cursor: pointer;
  position: relative;
  z-index: 2;
}

.aperture-slider::-webkit-slider-thumb {
  appearance: none;
  width: 28px;
  height: 28px;
  background: linear-gradient(145deg, #404040 0%, #1a1a1a 100%);
  border: 2px solid #555;
  border-radius: 50%;
  cursor: grab;
  box-shadow: 
    0 2px 8px rgba(0,0,0,0.4),
    inset 0 1px 2px rgba(255,255,255,0.2);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.aperture-slider::-webkit-slider-thumb:hover {
  transform: scale(1.1);
  box-shadow: 
    0 4px 12px rgba(0,0,0,0.5),
    inset 0 1px 2px rgba(255,255,255,0.2),
    0 0 0 3px rgba(99, 102, 241, 0.2);
}

.aperture-slider::-webkit-slider-thumb:active {
  cursor: grabbing;
  transform: scale(1.05);
}

.shutter-slider {
  height: 8px;
  background: var(--color-gray-200);
  border-radius: var(--radius-full);
  /* 8 labels, each is 12.5% wide, so offset by half (6.25%) to align thumb with label centers */
  width: calc(100% - 12.5%);
  margin: 0 6.25%;
}

.iso-slider {
  height: 8px;
  background: var(--color-gray-200);
  border-radius: var(--radius-full);
  /* 7 labels, each is 14.29% wide, so offset by half (7.14%) to align thumb with label centers */
  width: calc(100% - 14.29%);
  margin: 0 7.14%;
}

.shutter-slider::-webkit-slider-thumb,
.iso-slider::-webkit-slider-thumb {
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--color-black);
  border-radius: 50%;
  cursor: grab;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-fast);
}

.shutter-slider::-webkit-slider-thumb:hover,
.iso-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.aperture-stops,
.shutter-speeds,
.iso-stops {
  display: flex;
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--color-gray-500);
}

.aperture-stops span,
.shutter-speeds span,
.iso-stops span {
  flex: 1;
  text-align: center;
}

.aperture-stops span,
.shutter-speeds span,
.iso-stops span {
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.aperture-stops span.active,
.shutter-speeds span.active,
.iso-stops span.active {
  color: var(--color-black);
  font-weight: var(--font-weight-bold);
  transform: scale(1.1);
}

/* Aperture Result / DOF Preview */
.aperture-result {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.dof-preview {
  position: relative;
  background: linear-gradient(180deg, #a8d5e5 0%, #89c4b8 100%);
  border-radius: var(--radius-lg);
  height: 200px;
  overflow: hidden;
}

.dof-scene {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: var(--space-4);
}

/* Person silhouettes */
.dof-person {
  position: absolute;
  transition: filter 0.5s ease, opacity 0.5s ease;
}

.dof-person svg {
  display: block;
  width: 100%;
  height: 100%;
}

/* Main subject - always sharp, centered, largest */
.dof-person--subject {
  width: 48px;
  height: 108px;
  color: #1a1a1a;
  z-index: 3;
  left: 50%;
  bottom: 8px;
  transform: translateX(-50%);
}

/* Near person - foreground left, blurred at shallow DOF */
.dof-person--near {
  width: 38px;
  height: 86px;
  color: #444;
  z-index: 2;
  left: 20%;
  bottom: 18px;
}

/* Far person - background right, blurred at shallow DOF, smallest */
.dof-person--far {
  width: 32px;
  height: 72px;
  color: #555;
  z-index: 1;
  right: 20%;
  bottom: 28px;
}

.dof-label {
  position: absolute;
  bottom: var(--space-3);
  left: var(--space-3);
  display: flex;
  flex-direction: column;
  color: white;
  text-shadow: 0 1px 4px rgba(0,0,0,0.4);
  z-index: 10;
}

.dof-value {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-bold);
}

.dof-desc {
  font-size: var(--text-xs);
  opacity: 0.85;
}

.aperture-info {
  background: var(--color-gray-100);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.info-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.info-label {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-500);
  min-width: 80px;
}

.info-meter {
  flex: 1;
  height: 8px;
  background: var(--color-gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.meter-fill {
  height: 100%;
  background: var(--color-aperture);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
  width: 80%;
}

.meter-fill--dof {
  background: var(--color-focus);
}

.meter-fill--motion {
  background: var(--color-shutter);
}

.meter-fill--noise {
  background: var(--color-aurora-storm);
}

.info-value {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  min-width: 60px;
  text-align: right;
}

/* F-Stop Reference Grid */
.fstop-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-3);
}

@media (max-width: 1024px) {
  .fstop-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 640px) {
  .fstop-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.fstop-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

.fstop-card--wide {
  border-color: var(--color-aperture);
  border-width: 2px;
}

.fstop-card--caution {
  background: var(--color-gray-100);
  border-style: dashed;
}

.fstop-value {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-bold);
  font-family: var(--font-mono);
  margin-bottom: var(--space-2);
}

.fstop-traits {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin-bottom: var(--space-2);
}

.trait {
  display: inline-block;
  padding: 2px var(--space-2);
  font-size: var(--text-xs);
  border-radius: var(--radius-sm);
}

.trait--light {
  background: rgba(99, 102, 241, 0.1);
  color: var(--color-aperture);
}

.trait--dof {
  background: rgba(236, 72, 153, 0.1);
  color: var(--color-focus);
}

.trait--warning {
  background: rgba(239, 68, 68, 0.1);
  color: var(--color-aurora-storm);
}

.fstop-use {
  font-size: var(--text-xs);
  color: var(--color-gray-600);
  line-height: var(--leading-relaxed);
}

/* --------------------------------------------------------------------------
   Shutter Speed Section
   -------------------------------------------------------------------------- */
.shutter-demo {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-10);
}

@media (max-width: 768px) {
  .shutter-demo {
    grid-template-columns: 1fr;
  }
}

.shutter-visual {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.shutter-preview {
  background: linear-gradient(180deg, #e0e7ff 0%, #c7d2fe 100%);
  border-radius: var(--radius-lg);
  height: 200px;
  overflow: hidden;
  position: relative;
}

.motion-subject {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: flex;
  align-items: center;
}

.motion-object {
  width: 50px;
  height: 50px;
  background: var(--color-shutter);
  border-radius: 50%;
  position: relative;
  z-index: 2;
  flex-shrink: 0;
}

/* Motion trail - horizontal streak behind the ball */
.motion-blur {
  position: absolute;
  top: 50%;
  right: 25px; /* Start from center of the ball */
  transform: translateY(-50%);
  height: 50px;
  width: 0;
  background: linear-gradient(to left, var(--color-shutter) 0%, rgba(245, 158, 11, 0.3) 60%, transparent 100%);
  border-radius: 25px 0 0 25px;
  opacity: 0;
  transition: width 0.4s ease, opacity 0.4s ease, filter 0.4s ease;
}

.shutter-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.shutter-current {
  text-align: center;
  padding: var(--space-4);
  background: var(--color-black);
  color: white;
  border-radius: var(--radius-lg);
}

.shutter-current-value {
  display: block;
  font-size: var(--text-4xl);
  font-weight: var(--font-weight-bold);
  font-family: var(--font-mono);
}

.shutter-current-desc {
  font-size: var(--text-sm);
  color: var(--color-gray-400);
}

.shutter-meters {
  background: var(--color-gray-100);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

/* Handheld Rule */
.handheld-rule {
  margin-top: var(--space-10);
  padding: var(--space-6);
  background: var(--color-gray-100);
  border-radius: var(--radius-xl);
}

.rule-title {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-4);
}

.rule-content {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-6);
  align-items: center;
}

@media (max-width: 768px) {
  .rule-content {
    grid-template-columns: 1fr;
  }
}

.rule-formula {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-white);
  border-radius: var(--radius-lg);
}

.formula-text {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
}

.formula-fraction {
  display: flex;
  flex-direction: column;
  align-items: center;
  font-family: var(--font-mono);
  font-weight: var(--font-weight-bold);
}

.fraction-num {
  font-size: var(--text-xl);
}

.fraction-line {
  width: 100%;
  height: 2px;
  background: var(--color-black);
  margin: 2px 0;
}

.fraction-den {
  font-size: var(--text-xs);
  text-transform: lowercase;
}

.rule-examples {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.rule-example {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-sm);
}

.example-lens {
  font-weight: var(--font-weight-medium);
  min-width: 100px;
}

.example-arrow {
  color: var(--color-gray-400);
}

.example-speed {
  font-family: var(--font-mono);
  font-weight: var(--font-weight-bold);
}

/* Enhanced Reciprocal Rule Layout */
.rule-content-enhanced {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
}

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

.rule-left {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.rule-right {
  display: flex;
  flex-direction: column;
}

/* Focal Length Calculator */
.focal-calculator {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  border: 2px solid var(--color-gray-200);
}

.calc-label {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-600);
}

.calc-input-group {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.calc-input {
  width: 70px;
  padding: var(--space-2);
  font-size: var(--text-lg);
  font-family: var(--font-mono);
  font-weight: var(--font-weight-bold);
  text-align: center;
  border: 2px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  background: var(--color-white);
}

.calc-input:focus {
  outline: none;
  border-color: var(--color-black);
}

.calc-unit {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
}

.calc-arrow {
  font-size: var(--text-lg);
  color: var(--color-gray-400);
}

.calc-result {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
}

.calc-result-value {
  font-size: var(--text-2xl);
  font-family: var(--font-mono);
  font-weight: var(--font-weight-bold);
}

.calc-result-label {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
}

/* Crop Factor Toggle */
.crop-factor-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.crop-label {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
}

.crop-btn {
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  background: var(--color-white);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.crop-btn:hover {
  border-color: var(--color-gray-400);
}

.crop-btn.active {
  background: var(--color-black);
  color: var(--color-white);
  border-color: var(--color-black);
}

/* Focal Length Visual Scale */
.focal-scale {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  border: 1px solid var(--color-gray-200);
}

.scale-header {
  display: flex;
  justify-content: space-between;
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-gray-500);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-gray-200);
  margin-bottom: var(--space-3);
}

.scale-items {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.scale-item {
  display: grid;
  grid-template-columns: 50px 1fr 60px 70px;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  font-size: var(--text-sm);
}

.scale-item--highlight {
  background: rgba(0, 0, 0, 0.03);
  margin: 0 calc(-1 * var(--space-4));
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
}

.scale-focal {
  font-family: var(--font-mono);
  font-weight: var(--font-weight-semibold);
}

.scale-bar {
  height: 6px;
  background: linear-gradient(90deg, var(--color-shutter) 0%, var(--color-shutter) var(--bar-width), var(--color-gray-200) var(--bar-width));
  border-radius: var(--radius-full);
}

.scale-shutter {
  font-family: var(--font-mono);
  font-weight: var(--font-weight-bold);
  text-align: right;
}

.scale-type {
  font-size: var(--text-xs);
  color: var(--color-gray-500);
  text-align: right;
}

/* Stabilization Note */
.stabilization-note {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  border-left: 3px solid var(--color-shutter);
}

.stabilization-note--compact {
  align-items: center;
  margin-top: var(--space-2);
}

.stabilization-note--compact .stab-icon {
  width: 24px;
  height: 24px;
}

.stabilization-note--compact .stab-content {
  flex-direction: row;
  gap: var(--space-1);
}

.stab-icon {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(245, 158, 11, 0.1);
  border-radius: var(--radius-md);
  color: var(--color-shutter);
}

.stab-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  font-size: var(--text-sm);
}

.stab-content strong {
  color: var(--color-black);
}

.stab-content span {
  color: var(--color-gray-600);
  line-height: var(--leading-relaxed);
}

.rule-note {
  grid-column: 1 / -1;
  font-size: var(--text-sm);
  color: var(--color-gray-600);
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-gray-200);
}

/* Badge color overrides for guide page accent colors */
.guide-page .badge--yes {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-iso);
}

.guide-page .badge--caution {
  background: rgba(245, 158, 11, 0.1);
  color: var(--color-shutter);
}

.guide-page .badge--no {
  background: rgba(239, 68, 68, 0.1);
  color: var(--color-aurora-storm);
}

/* --------------------------------------------------------------------------
   ISO Section
   -------------------------------------------------------------------------- */
.iso-demo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-10);
}

@media (max-width: 768px) {
  .iso-demo {
    grid-template-columns: 1fr;
  }
}

.iso-visual {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.iso-preview {
  position: relative;
  background: linear-gradient(135deg, #334155 0%, #1e293b 100%);
  border-radius: var(--radius-lg);
  height: 200px;
  overflow: hidden;
}

.iso-image {
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 30% 40%, rgba(255,255,255,0.1) 0%, transparent 50%),
    radial-gradient(circle at 70% 60%, rgba(255,255,255,0.05) 0%, transparent 40%);
}

.noise-overlay {
  position: absolute;
  inset: 0;
  opacity: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  mix-blend-mode: overlay;
  transition: opacity var(--transition-slow);
}

.iso-current {
  position: absolute;
  bottom: var(--space-3);
  right: var(--space-3);
  display: flex;
  align-items: baseline;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  background: rgba(0,0,0,0.7);
  border-radius: var(--radius-md);
  color: white;
}

.iso-current-label {
  font-size: var(--text-xs);
  opacity: 0.7;
}

.iso-current-value {
  font-size: var(--text-xl);
  font-weight: var(--font-weight-bold);
  font-family: var(--font-mono);
}

.iso-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.iso-meters {
  background: var(--color-gray-100);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.iso-quality {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3);
  background: var(--color-gray-100);
  border-radius: var(--radius-lg);
}

.quality-indicator {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  transition: background-color var(--transition-base);
}

.quality-indicator--good {
  background: var(--color-iso);
}

.quality-indicator--moderate {
  background: var(--color-shutter);
}

.quality-indicator--noisy {
  background: var(--color-aurora-storm);
}

.quality-text {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
}

/* ISO Reference Grid */
.iso-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
}

@media (max-width: 1024px) {
  .iso-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .iso-grid {
    grid-template-columns: 1fr;
  }
}

.iso-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

.iso-card--clean { border-top: 3px solid var(--color-iso); }
.iso-card--good { border-top: 3px solid var(--color-aurora-quiet); }
.iso-card--moderate { border-top: 3px solid var(--color-shutter); }
.iso-card--high { border-top: 3px solid var(--color-aurora-storm); }

.iso-range {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-bold);
  font-family: var(--font-mono);
  margin-bottom: var(--space-2);
}

.iso-quality-badge {
  display: inline-block;
  padding: 2px var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-sm);
  background: var(--color-gray-100);
  margin-bottom: var(--space-2);
}

.iso-card--clean .iso-quality-badge { background: rgba(16, 185, 129, 0.1); color: var(--color-iso); }
.iso-card--good .iso-quality-badge { background: rgba(34, 197, 94, 0.1); color: var(--color-aurora-quiet); }
.iso-card--moderate .iso-quality-badge { background: rgba(245, 158, 11, 0.1); color: var(--color-shutter); }
.iso-card--high .iso-quality-badge { background: rgba(239, 68, 68, 0.1); color: var(--color-aurora-storm); }

.iso-card p {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-3);
}

.iso-when {
  font-size: var(--text-xs);
  color: var(--color-gray-500);
  padding-top: var(--space-2);
  border-top: 1px solid var(--color-gray-100);
}

.iso-when strong {
  color: var(--color-gray-700);
}

/* --------------------------------------------------------------------------
   Focus Section
   -------------------------------------------------------------------------- */
.focus-modes {
  margin-bottom: var(--space-10);
}

.focus-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
}

@media (max-width: 1024px) {
  .focus-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .focus-grid {
    grid-template-columns: 1fr;
  }
}

.focus-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}

.focus-card--highlight {
  border-color: var(--color-focus);
  border-width: 2px;
}

.focus-icon {
  width: 48px;
  height: 48px;
  margin-bottom: var(--space-3);
  color: var(--color-gray-600);
}

.focus-card--highlight .focus-icon {
  color: var(--color-focus);
}

.focus-card h4 {
  font-size: var(--text-base);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-2);
}

.focus-names {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin-bottom: var(--space-3);
}

.camera-brand {
  font-size: var(--text-xs);
  padding: 2px var(--space-2);
  background: var(--color-gray-100);
  border-radius: var(--radius-sm);
  color: var(--color-gray-600);
}

.focus-card p {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-3);
}

.focus-best {
  font-size: var(--text-xs);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-gray-100);
  color: var(--color-gray-500);
}

.focus-best strong {
  color: var(--color-black);
}

/* Focus Areas Grid */
.area-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
}

@media (max-width: 1024px) {
  .area-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .area-grid {
    grid-template-columns: 1fr;
  }
}

.area-card {
  background: var(--color-gray-100);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

.area-visual {
  margin-bottom: var(--space-3);
}

.area-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 4/3;
  background: var(--color-gray-200);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.area-point {
  position: absolute;
}

.area-point--single {
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 12px;
  height: 12px;
  border: 2px solid var(--color-focus);
  background: rgba(236, 72, 153, 0.2);
}

.area-point--zone {
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 50%;
  height: 50%;
  border: 2px solid var(--color-focus);
  background: rgba(236, 72, 153, 0.1);
  border-radius: var(--radius-sm);
}

.area-point--wide {
  inset: 10%;
  border: 2px dashed var(--color-focus);
  background: rgba(236, 72, 153, 0.05);
  border-radius: var(--radius-sm);
}

.area-point--eye {
  top: 35%;
  left: 40%;
  width: 20%;
  height: 15%;
  border: 2px solid var(--color-focus);
  background: rgba(236, 72, 153, 0.2);
  border-radius: 50%;
}

.area-card h4 {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-2);
}

.area-card p {
  font-size: var(--text-xs);
  color: var(--color-gray-600);
}

/* --------------------------------------------------------------------------
   White Balance Section
   -------------------------------------------------------------------------- */
.wb-visual {
  margin-bottom: var(--space-10);
}

.kelvin-scale {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
}

.kelvin-bar {
  position: relative;
  margin-bottom: var(--space-4);
}

.kelvin-gradient {
  height: 32px;
  border-radius: var(--radius-md);
  background: linear-gradient(90deg, 
    #ff8c00 0%, 
    #ffa500 15%, 
    #ffd700 25%, 
    #fffacd 35%, 
    #ffffff 45%, 
    #f0f8ff 55%, 
    #add8e6 70%, 
    #87ceeb 85%, 
    #6495ed 100%
  );
}

.kelvin-markers {
  position: relative;
  height: 60px;
  margin-top: var(--space-2);
}

.kelvin-marker {
  position: absolute;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

/* First marker: align to left edge */
.kelvin-marker:first-child {
  transform: translateX(0);
  align-items: flex-start;
  text-align: left;
}

/* Last marker: align to right edge */
.kelvin-marker:last-child {
  transform: translateX(-100%);
  align-items: flex-end;
  text-align: right;
}

.marker-value {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  font-weight: var(--font-weight-semibold);
}

.marker-label {
  font-size: var(--text-xs);
  color: var(--color-gray-500);
}

.kelvin-labels {
  display: flex;
  justify-content: space-between;
}

.kelvin-label {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
}

.kelvin-label--warm { color: #f59e0b; }
.kelvin-label--cool { color: #3b82f6; }

/* WB Presets */
.preset-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
}

@media (max-width: 1024px) {
  .preset-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 640px) {
  .preset-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.preset-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  text-align: center;
}

.preset-card--custom {
  border-style: dashed;
}

.preset-icon {
  width: 40px;
  height: 40px;
  margin: 0 auto var(--space-2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xl);
  border-radius: var(--radius-md);
}

.preset-icon--auto { background: var(--color-gray-100); font-size: var(--text-xs); font-weight: bold; }
.preset-icon--daylight { background: #fef3c7; }
.preset-icon--cloudy { background: #f3f4f6; }
.preset-icon--shade { background: #dbeafe; }
.preset-icon--tungsten { background: #fef3c7; color: #f59e0b; }
.preset-icon--fluoro { background: #d1fae5; }
.preset-icon--flash { background: #fff7ed; }
.preset-icon--custom { background: var(--color-gray-100); font-size: var(--text-sm); font-weight: bold; }

.preset-card h4 {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-1);
}

.preset-kelvin {
  display: block;
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--color-gray-500);
  margin-bottom: var(--space-2);
}

.preset-card p {
  font-size: var(--text-xs);
  color: var(--color-gray-600);
  line-height: var(--leading-relaxed);
}

/* --------------------------------------------------------------------------
   Metering Section
   -------------------------------------------------------------------------- */
.metering-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
  margin-bottom: var(--space-10);
}

@media (max-width: 1024px) {
  .metering-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .metering-grid {
    grid-template-columns: 1fr;
  }
}

.metering-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}

.metering-card--highlight {
  border-color: var(--color-black);
  border-width: 2px;
}

.metering-visual {
  margin-bottom: var(--space-4);
}

.metering-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 4/3;
  background: var(--color-gray-100);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.metering-pattern {
  position: absolute;
  inset: 0;
}

.metering-pattern--matrix {
  background: 
    linear-gradient(90deg, transparent 24%, var(--color-gray-300) 25%, var(--color-gray-300) 26%, transparent 27%),
    linear-gradient(transparent 24%, var(--color-gray-300) 25%, var(--color-gray-300) 26%, transparent 27%);
  background-size: 20% 20%;
}

.metering-pattern--center {
  background: radial-gradient(ellipse 60% 50% at center, var(--color-gray-300) 0%, transparent 70%);
}

.metering-pattern--spot {
  background: radial-gradient(circle 10% at center, var(--color-black) 0%, transparent 100%);
}

.metering-pattern--highlight {
  background: 
    linear-gradient(135deg, var(--color-gray-300) 0%, transparent 40%),
    linear-gradient(45deg, transparent 60%, var(--color-gray-300) 100%);
}

.metering-card h3 {
  font-size: var(--text-base);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-2);
}

.metering-card p {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-3);
}

.metering-when {
  font-size: var(--text-xs);
  color: var(--color-gray-500);
  margin-bottom: var(--space-2);
}

.metering-when strong {
  color: var(--color-black);
}

.metering-tip {
  font-size: var(--text-xs);
  color: var(--color-gray-400);
  font-style: italic;
}

/* Exposure Compensation */
.exposure-comp {
  padding: var(--space-6);
  background: var(--color-gray-100);
  border-radius: var(--radius-xl);
}

.comp-visual {
  margin-bottom: var(--space-4);
}

.comp-scale {
  position: relative;
  height: 40px;
  background: linear-gradient(90deg, #1e293b 0%, #64748b 50%, #fef9c3 100%);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-2);
}

.comp-markers {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
  padding: 0 var(--space-4);
}

.comp-marker {
  font-size: var(--text-sm);
  font-family: var(--font-mono);
  font-weight: var(--font-weight-medium);
  color: white;
  text-shadow: 0 1px 2px rgba(0,0,0,0.5);
}

.comp-marker--center {
  font-weight: var(--font-weight-bold);
  font-size: var(--text-base);
}

.comp-labels {
  display: flex;
  justify-content: space-between;
}

.comp-label {
  font-size: var(--text-xs);
  color: var(--color-gray-500);
}

.comp-tips p {
  font-size: var(--text-sm);
  color: var(--color-gray-700);
  margin-bottom: var(--space-3);
}

.comp-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.comp-list li {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
  padding-left: var(--space-4);
  position: relative;
}

.comp-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--color-gray-400);
}

.comp-list strong {
  color: var(--color-black);
}

/* --------------------------------------------------------------------------
   Shooting Modes Section
   -------------------------------------------------------------------------- */
.modes-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
  margin-bottom: var(--space-10);
}

@media (max-width: 1024px) {
  .modes-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .modes-grid {
    grid-template-columns: 1fr;
  }
}

.mode-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}

.mode-card--popular {
  border-color: var(--color-aperture);
  border-width: 2px;
  position: relative;
}

.mode-card--popular::before {
  content: 'Most Used';
  position: absolute;
  top: -10px;
  right: var(--space-3);
  padding: 2px var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  background: var(--color-aperture);
  color: white;
  border-radius: var(--radius-sm);
}

.mode-card--advanced {
  background: var(--color-black);
  color: white;
  border: none;
}

.mode-dial {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xl);
  font-weight: var(--font-weight-bold);
  border: 3px solid var(--color-gray-300);
  border-radius: 50%;
  margin-bottom: var(--space-3);
}

.mode-card--advanced .mode-dial {
  border-color: var(--color-gray-600);
}

.mode-alt {
  font-size: var(--text-sm);
  color: var(--color-gray-400);
  margin-left: 2px;
}

.mode-card h3 {
  font-size: var(--text-base);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-3);
}

.mode-controls {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  margin-bottom: var(--space-3);
  padding: var(--space-3);
  background: var(--color-gray-50);
  border-radius: var(--radius-md);
}

.mode-card--advanced .mode-controls {
  background: rgba(255,255,255,0.1);
}

.control-item {
  font-size: var(--text-xs);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}

.control-item--auto {
  color: var(--color-gray-500);
}

.control-item--you {
  background: var(--color-black);
  color: white;
}

.mode-card--advanced .control-item--you {
  background: white;
  color: var(--color-black);
}

.mode-card p {
  font-size: var(--text-sm);
  color: var(--color-gray-600);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-3);
}

.mode-card--advanced p {
  color: var(--color-gray-400);
}

.mode-when {
  font-size: var(--text-xs);
  color: var(--color-gray-500);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-gray-100);
}

.mode-card--advanced .mode-when {
  border-top-color: var(--color-gray-700);
  color: var(--color-gray-400);
}

.mode-when strong {
  color: var(--color-gray-700);
}

.mode-card--advanced .mode-when strong {
  color: var(--color-gray-300);
}

/* Mode Recommendation Flow */
.mode-recommendation {
  padding: var(--space-6);
  background: var(--color-gray-100);
  border-radius: var(--radius-xl);
}

.mode-recommendation h3 {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-5);
}

/* New Flowchart Styles */
.mode-flowchart {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.flow-step {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.flow-question-card {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.flow-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  font-size: var(--text-sm);
  font-weight: var(--font-weight-bold);
  background: var(--color-black);
  color: var(--color-white);
  border-radius: 50%;
  flex-shrink: 0;
}

.flow-q-text {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
}

.flow-branches {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
  padding-left: var(--space-10);
}

@media (max-width: 640px) {
  .flow-branches {
    grid-template-columns: 1fr;
    padding-left: var(--space-6);
  }
}

.flow-branch {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.branch-label {
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.flow-branch--yes .branch-label {
  color: var(--color-iso);
}

.flow-branch--no .branch-label {
  color: var(--color-gray-500);
}

.branch-arrow {
  font-size: var(--text-lg);
  color: var(--color-gray-400);
}

.flow-result {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  background: rgba(16, 185, 129, 0.08);
  border: 1px solid rgba(16, 185, 129, 0.2);
  border-radius: var(--radius-lg);
}

.flow-result--default {
  background: var(--color-gray-50);
  border-color: var(--color-gray-200);
}

.result-dial {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  font-size: var(--text-lg);
  font-weight: var(--font-weight-bold);
  background: var(--color-white);
  border: 2px solid var(--color-iso);
  border-radius: 50%;
  color: var(--color-iso);
  flex-shrink: 0;
}

.result-dial--manual {
  border-color: var(--color-black);
  color: var(--color-black);
}

.flow-result--default .result-dial {
  border-color: var(--color-gray-400);
  color: var(--color-gray-600);
}

.result-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.result-info strong {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
}

.result-info span {
  font-size: var(--text-xs);
  color: var(--color-gray-600);
}

.mode-tip {
  margin-top: var(--space-5);
  padding: var(--space-4);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  border-left: 3px solid var(--color-aperture);
}

.mode-tip strong {
  color: var(--color-aperture);
}

/* Guide page uses row layout for cheat items */
.guide-page .cheat-item {
  flex-direction: row;
  justify-content: space-between;
  align-items: center;
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
}

.guide-page .cheat-answer {
  font-family: var(--font-mono);
}

/* Animations and scroll-margin-top use shared definitions from styles.css */

/* --------------------------------------------------------------------------
   Night Vision Mode — Camera Guide Specific
   -------------------------------------------------------------------------- */
body.night-vision.guide-page {
  --color-aperture: #993333;
  --color-shutter: #996633;
  --color-iso: #339933;
  --color-focus: #993366;
}

/* Exposure Simulator in Night Vision */
body.night-vision .triangle-control {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .triangle-control:hover {
  box-shadow: 0 8px 32px rgba(100, 30, 30, 0.2);
}

body.night-vision .control-btn {
  background: var(--nv-bg-elevated);
  border-color: var(--nv-border);
  color: var(--nv-text);
}

body.night-vision .control-btn:hover {
  background: var(--nv-text);
  color: var(--nv-bg);
  border-color: var(--nv-text);
}

body.night-vision .control-value {
  color: var(--nv-text);
}

body.night-vision .control-label,
body.night-vision .control-stops {
  color: var(--nv-text-dim);
}

body.night-vision .exposure-center {
  color: var(--nv-text);
}

body.night-vision .meter-value {
  color: var(--nv-text);
}

body.night-vision .meter-label {
  color: var(--nv-text-dim);
}

body.night-vision .exposure-status {
  color: var(--nv-text-muted);
}

body.night-vision .effect-bar {
  background: var(--nv-bg-elevated);
}

body.night-vision .effect-fill {
  background: var(--nv-text);
}

body.night-vision .effect-label {
  color: var(--nv-text-dim);
}

body.night-vision .effect-range {
  color: var(--nv-text-dim);
}

body.night-vision .control-effect {
  border-left-color: var(--nv-border);
}

body.night-vision .action-btn {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
  color: var(--nv-text);
}

body.night-vision .action-btn:hover {
  background: var(--nv-text);
  color: var(--nv-bg);
  border-color: var(--nv-text);
}

body.night-vision .action-hint {
  color: var(--nv-text-dim);
}

body.night-vision .hint-icon {
  background: var(--nv-bg-elevated);
}

/* Equivalent Exposures in Night Vision */
body.night-vision .equivalent-exposures {
  background: var(--nv-bg-elevated);
  border-color: var(--nv-border);
}

body.night-vision .equiv-title {
  color: var(--nv-text);
}

body.night-vision .equiv-subtitle {
  color: var(--nv-text-muted);
}

body.night-vision .equiv-card {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .equiv-card:hover {
  border-color: var(--nv-text-dim);
}

body.night-vision .equiv-card.active {
  background: var(--nv-text);
  border-color: var(--nv-text);
  color: var(--nv-bg);
}

body.night-vision .equiv-values {
  color: var(--nv-text);
}

body.night-vision .equiv-card.active .equiv-values {
  color: var(--nv-bg);
}

body.night-vision .equiv-effect {
  background: var(--nv-bg-elevated);
  color: var(--nv-text-muted);
}

/* Aperture Demo in Night Vision */
body.night-vision .fstop-display {
  background: var(--nv-text);
  color: var(--nv-bg);
}

body.night-vision .aperture-stops span,
body.night-vision .shutter-speeds span,
body.night-vision .iso-stops span {
  color: var(--nv-text-dim);
}

body.night-vision .aperture-stops span.active,
body.night-vision .shutter-speeds span.active,
body.night-vision .iso-stops span.active {
  color: var(--nv-text);
}

body.night-vision .aperture-info,
body.night-vision .iso-meters,
body.night-vision .shutter-meters {
  background: var(--nv-bg-elevated);
}

body.night-vision .info-label {
  color: var(--nv-text-dim);
}

body.night-vision .info-meter {
  background: var(--nv-border);
}

body.night-vision .meter-fill {
  background: var(--nv-text);
}

body.night-vision .info-value {
  color: var(--nv-text);
}

body.night-vision .dof-label {
  color: var(--nv-text);
}

/* F-Stop Grid in Night Vision */
body.night-vision .fstop-card {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .fstop-card--wide {
  border-color: var(--nv-text-dim);
}

body.night-vision .fstop-card--caution {
  background: var(--nv-bg-elevated);
}

body.night-vision .fstop-value {
  color: var(--nv-text);
}

body.night-vision .fstop-use {
  color: var(--nv-text-muted);
}

body.night-vision .trait {
  color: var(--nv-text-muted);
}

body.night-vision .trait--light {
  background: rgba(153, 51, 51, 0.2);
  color: var(--nv-text);
}

body.night-vision .trait--dof {
  background: rgba(153, 51, 102, 0.2);
  color: var(--nv-text);
}

body.night-vision .trait--warning {
  background: rgba(153, 51, 51, 0.3);
  color: var(--nv-accent);
}

/* Shutter Demo in Night Vision */
body.night-vision .shutter-current {
  background: var(--nv-text);
  color: var(--nv-bg);
}

body.night-vision .shutter-current-desc {
  color: var(--nv-bg-card);
}

body.night-vision .shutter-slider,
body.night-vision .iso-slider {
  background: var(--nv-border);
}

/* Handheld Rule in Night Vision */
body.night-vision .handheld-rule {
  background: var(--nv-bg-elevated);
}

body.night-vision .rule-title {
  color: var(--nv-text);
}

body.night-vision .rule-formula {
  background: var(--nv-bg-card);
}

body.night-vision .formula-text {
  color: var(--nv-text-muted);
}

body.night-vision .fraction-line {
  background: var(--nv-text);
}

body.night-vision .rule-example {
  color: var(--nv-text-muted);
}

body.night-vision .example-lens {
  color: var(--nv-text);
}

body.night-vision .example-speed {
  color: var(--nv-text);
}

body.night-vision .focal-calculator {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .calc-label {
  color: var(--nv-text-muted);
}

body.night-vision .calc-input {
  background: var(--nv-bg);
  border-color: var(--nv-border);
  color: var(--nv-text);
}

body.night-vision .calc-input:focus {
  border-color: var(--nv-text);
}

body.night-vision .calc-unit,
body.night-vision .calc-arrow,
body.night-vision .calc-result-label {
  color: var(--nv-text-dim);
}

body.night-vision .calc-result-value {
  color: var(--nv-text);
}

body.night-vision .crop-btn {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
  color: var(--nv-text-muted);
}

body.night-vision .crop-btn:hover {
  border-color: var(--nv-text-dim);
}

body.night-vision .crop-btn.active {
  background: var(--nv-text);
  color: var(--nv-bg);
  border-color: var(--nv-text);
}

body.night-vision .focal-scale {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .scale-header {
  color: var(--nv-text-dim);
  border-bottom-color: var(--nv-border);
}

body.night-vision .scale-focal,
body.night-vision .scale-shutter {
  color: var(--nv-text);
}

body.night-vision .scale-type {
  color: var(--nv-text-dim);
}

body.night-vision .stabilization-note {
  background: var(--nv-bg-card);
  border-left-color: var(--nv-text-dim);
}

body.night-vision .stab-icon {
  background: rgba(153, 102, 51, 0.2);
  color: var(--nv-text);
}

body.night-vision .stab-content strong {
  color: var(--nv-text);
}

body.night-vision .stab-content span {
  color: var(--nv-text-muted);
}

body.night-vision .rule-note {
  color: var(--nv-text-muted);
  border-top-color: var(--nv-border);
}

/* ISO Cards in Night Vision */
body.night-vision .iso-card {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .iso-card--clean { border-top-color: #339933; }
body.night-vision .iso-card--good { border-top-color: #336633; }
body.night-vision .iso-card--moderate { border-top-color: #996633; }
body.night-vision .iso-card--high { border-top-color: var(--nv-text); }

body.night-vision .iso-range {
  color: var(--nv-text);
}

body.night-vision .iso-quality-badge {
  background: var(--nv-bg-elevated);
}

body.night-vision .iso-card p {
  color: var(--nv-text-muted);
}

body.night-vision .iso-when {
  color: var(--nv-text-dim);
  border-top-color: var(--nv-border);
}

body.night-vision .iso-when strong {
  color: var(--nv-text);
}

body.night-vision .iso-quality {
  background: var(--nv-bg-elevated);
}

body.night-vision .quality-text {
  color: var(--nv-text-muted);
}

/* Focus Section in Night Vision */
body.night-vision .focus-card {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .focus-card--highlight {
  border-color: var(--nv-text-dim);
}

body.night-vision .focus-icon {
  color: var(--nv-text-muted);
}

body.night-vision .focus-card--highlight .focus-icon {
  color: var(--nv-text);
}

body.night-vision .focus-card h4 {
  color: var(--nv-text);
}

body.night-vision .camera-brand {
  background: var(--nv-bg-elevated);
  color: var(--nv-text-muted);
}

body.night-vision .focus-card p {
  color: var(--nv-text-muted);
}

body.night-vision .focus-best {
  color: var(--nv-text-dim);
  border-top-color: var(--nv-border);
}

body.night-vision .focus-best strong {
  color: var(--nv-text);
}

body.night-vision .area-card {
  background: var(--nv-bg-elevated);
}

body.night-vision .area-frame {
  background: var(--nv-bg-card);
}

body.night-vision .area-card h4 {
  color: var(--nv-text);
}

body.night-vision .area-card p {
  color: var(--nv-text-muted);
}

body.night-vision .area-point {
  border-color: var(--nv-text);
  background: rgba(204, 51, 51, 0.2);
}

/* White Balance in Night Vision */
body.night-vision .kelvin-scale {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .marker-value {
  color: var(--nv-text);
}

body.night-vision .marker-label {
  color: var(--nv-text-dim);
}

body.night-vision .kelvin-label {
  color: var(--nv-text-dim);
}

body.night-vision .preset-card {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .preset-card h4 {
  color: var(--nv-text);
}

body.night-vision .preset-kelvin {
  color: var(--nv-text-dim);
}

body.night-vision .preset-card p {
  color: var(--nv-text-muted);
}

body.night-vision .preset-icon {
  background: var(--nv-bg-elevated);
}

/* Metering Section in Night Vision */
body.night-vision .metering-card {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .metering-card--highlight {
  border-color: var(--nv-text);
}

body.night-vision .metering-frame {
  background: var(--nv-bg-elevated);
}

body.night-vision .metering-pattern--matrix {
  background: 
    linear-gradient(90deg, transparent 24%, var(--nv-border) 25%, var(--nv-border) 26%, transparent 27%),
    linear-gradient(transparent 24%, var(--nv-border) 25%, var(--nv-border) 26%, transparent 27%);
  background-size: 20% 20%;
}

body.night-vision .metering-pattern--center {
  background: radial-gradient(ellipse 60% 50% at center, var(--nv-border) 0%, transparent 70%);
}

body.night-vision .metering-pattern--spot {
  background: radial-gradient(circle 10% at center, var(--nv-text) 0%, transparent 100%);
}

body.night-vision .metering-card h3 {
  color: var(--nv-text);
}

body.night-vision .metering-card p {
  color: var(--nv-text-muted);
}

body.night-vision .metering-when {
  color: var(--nv-text-dim);
}

body.night-vision .metering-when strong {
  color: var(--nv-text);
}

body.night-vision .metering-tip {
  color: var(--nv-text-dim);
}

body.night-vision .exposure-comp {
  background: var(--nv-bg-elevated);
}

body.night-vision .comp-markers .comp-marker {
  color: var(--nv-text);
}

body.night-vision .comp-label {
  color: var(--nv-text-dim);
}

body.night-vision .comp-tips p {
  color: var(--nv-text-muted);
}

body.night-vision .comp-list li {
  color: var(--nv-text-muted);
}

body.night-vision .comp-list li::before {
  color: var(--nv-text-dim);
}

body.night-vision .comp-list strong {
  color: var(--nv-text);
}

/* Shooting Modes in Night Vision */
body.night-vision .mode-card {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .mode-card--popular {
  border-color: var(--nv-text-dim);
}

body.night-vision .mode-card--popular::before {
  background: var(--nv-text);
}

body.night-vision .mode-card--advanced {
  background: #200000;
  border: 1px solid var(--nv-border);
}

body.night-vision .mode-dial {
  border-color: var(--nv-border);
  color: var(--nv-text);
}

body.night-vision .mode-card h3 {
  color: var(--nv-text);
}

body.night-vision .mode-controls {
  background: var(--nv-bg-elevated);
}

body.night-vision .mode-card--advanced .mode-controls {
  background: rgba(204, 51, 51, 0.1);
}

body.night-vision .control-item--auto {
  color: var(--nv-text-dim);
}

body.night-vision .control-item--you {
  background: var(--nv-text);
  color: var(--nv-bg);
}

body.night-vision .mode-card--advanced .control-item--you {
  background: var(--nv-text);
  color: var(--nv-bg);
}

body.night-vision .mode-card p {
  color: var(--nv-text-muted);
}

body.night-vision .mode-card--advanced p {
  color: var(--nv-text-dim);
}

body.night-vision .mode-when {
  color: var(--nv-text-dim);
  border-top-color: var(--nv-border);
}

body.night-vision .mode-when strong {
  color: var(--nv-text);
}

body.night-vision .mode-recommendation {
  background: var(--nv-bg-elevated);
}

body.night-vision .mode-recommendation h3 {
  color: var(--nv-text);
}

body.night-vision .flow-question-card {
  background: var(--nv-bg-card);
}

body.night-vision .flow-number {
  background: var(--nv-text);
  color: var(--nv-bg);
}

body.night-vision .flow-q-text {
  color: var(--nv-text);
}

body.night-vision .branch-label {
  color: var(--nv-text-muted);
}

body.night-vision .flow-branch--yes .branch-label {
  color: #339933;
}

body.night-vision .branch-arrow {
  color: var(--nv-text-dim);
}

body.night-vision .flow-result {
  background: rgba(51, 153, 51, 0.1);
  border-color: rgba(51, 153, 51, 0.3);
}

body.night-vision .flow-result--default {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}

body.night-vision .result-dial {
  background: var(--nv-bg);
  border-color: #339933;
  color: #339933;
}

body.night-vision .result-dial--manual {
  border-color: var(--nv-text);
  color: var(--nv-text);
}

body.night-vision .flow-result--default .result-dial {
  border-color: var(--nv-text-dim);
  color: var(--nv-text-dim);
}

body.night-vision .result-info strong {
  color: var(--nv-text);
}

body.night-vision .result-info span {
  color: var(--nv-text-muted);
}

body.night-vision .mode-tip {
  background: var(--nv-bg-card);
  border-left-color: var(--nv-text-dim);
}

body.night-vision .mode-tip strong {
  color: var(--nv-text);
}

/* Guide Cheat Items in Night Vision */
body.night-vision .guide-page .cheat-item {
  background: var(--nv-bg-card);
  border-color: var(--nv-border);
}