/* ============================================================
   LEVRON AEROGEL FELT — Product Landing Page Styles
   Premium Deep-Tech Product Page Design System Extension
   ============================================================ */

/* --- Felt Hero Enhancements --- */
.felt-hero__micro-strip {
  display: flex;
  gap: 2px;
  margin-top: 48px;
  border-radius: var(--radius-md);
  overflow: hidden;
  max-width: 680px;
}

.felt-hero__micro-item {
  flex: 1;
  padding: 16px 14px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-subtle);
  text-align: center;
  transition: all var(--transition-base);
}

.felt-hero__micro-item:first-child {
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.felt-hero__micro-item:last-child {
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.felt-hero__micro-item:hover {
  background: rgba(232, 81, 45, 0.06);
  border-color: rgba(232, 81, 45, 0.15);
}

.felt-hero__micro-value {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--accent-heat-light);
  margin-bottom: 4px;
}

.felt-hero__micro-label {
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--text-tertiary);
  letter-spacing: 0.02em;
}

/* --- Sticky Section Navigation --- */
.felt-section-nav {
  position: sticky;
  top: 72px;
  z-index: 900;
  background: rgba(10, 12, 16, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  transition: all var(--transition-base);
}

.felt-section-nav__inner {
  display: flex;
  gap: 0;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding: 0 8px;
}

.felt-section-nav__inner::-webkit-scrollbar {
  display: none;
}

.felt-section-nav__link {
  flex-shrink: 0;
  padding: 14px 16px;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--text-tertiary);
  text-transform: uppercase;
  white-space: nowrap;
  position: relative;
  transition: all var(--transition-fast);
}

.felt-section-nav__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 16px;
  right: 16px;
  height: 2px;
  background: var(--accent-heat);
  transform: scaleX(0);
  transition: transform var(--transition-base);
}

.felt-section-nav__link:hover {
  color: var(--text-secondary);
}

.felt-section-nav__link.active {
  color: var(--accent-heat-light);
}

.felt-section-nav__link.active::after {
  transform: scaleX(1);
}

/* --- Product Overview Section --- */
.felt-overview__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.felt-overview__visual {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.felt-overview__visual img {
  width: 100%;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-subtle);
}

.felt-overview__content {
  max-width: 540px;
}

.felt-overview__features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 32px;
}

.felt-overview__feature {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 14px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.felt-overview__feature:hover {
  border-color: rgba(232, 81, 45, 0.12);
  background: rgba(232, 81, 45, 0.04);
}

.felt-overview__feature-icon {
  flex-shrink: 0;
  font-size: 1.25rem;
  margin-top: 2px;
}

.felt-overview__feature h5 {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.felt-overview__feature p {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  line-height: 1.5;
}

/* --- Why Felt Format --- */
.felt-format__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.felt-format__points {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 36px;
}

.felt-format__point {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 20px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.felt-format__point:hover {
  border-color: var(--border-medium);
  transform: translateX(4px);
}

.felt-format__point-icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: rgba(232, 81, 45, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.felt-format__point h5 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.felt-format__point p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.felt-format__visual {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.felt-format__visual img {
  width: 100%;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-subtle);
}

/* --- Performance Grid --- */
.felt-perf__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.felt-perf__card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  position: relative;
  overflow: hidden;
  transition: all var(--transition-base);
}

.felt-perf__card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-heat);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.felt-perf__card:hover {
  border-color: var(--border-medium);
  transform: translateY(-3px);
  box-shadow: var(--shadow-card);
}

.felt-perf__card:hover::before {
  transform: scaleX(1);
}

.felt-perf__card--highlight {
  border-color: rgba(232, 81, 45, 0.15);
  background: linear-gradient(180deg, rgba(232, 81, 45, 0.04) 0%, var(--bg-secondary) 100%);
}

.felt-perf__card--highlight::before {
  transform: scaleX(1);
}

.felt-perf__card-header {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 12px;
}

.felt-perf__card-value {
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.felt-perf__card-unit {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent-heat-light);
  margin-top: 4px;
  margin-bottom: 12px;
}

.felt-perf__card-desc {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.felt-perf__card-detail {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-tertiary);
}

/* --- Material Properties Table --- */
.felt-specs__table-wrap {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-top: 48px;
}

.felt-specs__table {
  width: 100%;
  border-collapse: collapse;
}

.felt-specs__table th {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  background: rgba(255, 255, 255, 0.02);
  padding: 16px 24px;
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
}

.felt-specs__table td {
  padding: 14px 24px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
}

.felt-specs__table td:first-child {
  font-weight: 600;
  color: var(--text-primary);
}

.felt-specs__table td:last-child {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--accent-heat-light);
}

.felt-specs__table tbody tr:hover {
  background: rgba(255, 255, 255, 0.02);
}

.felt-specs__table tbody tr:last-child td {
  border-bottom: none;
}

/* --- Material Science Section --- */
.felt-science__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.felt-science__visual {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.felt-science__visual img {
  width: 100%;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-subtle);
}

.felt-science__blocks {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 32px;
}

.felt-science__block {
  padding: 20px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--accent-heat);
  transition: all var(--transition-base);
}

.felt-science__block:hover {
  background: rgba(232, 81, 45, 0.04);
  border-color: rgba(232, 81, 45, 0.12);
}

.felt-science__block h5 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.felt-science__block p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- Application Clusters --- */
.felt-apps__clusters {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  margin-top: 48px;
}

.felt-app-cluster {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.felt-app-cluster::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-heat);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.felt-app-cluster:hover {
  border-color: var(--border-medium);
  box-shadow: var(--shadow-card);
}

.felt-app-cluster:hover::before {
  transform: scaleX(1);
}

.felt-app-cluster__header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}

.felt-app-cluster__icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: rgba(232, 81, 45, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.375rem;
}

.felt-app-cluster__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-heat-light);
}

.felt-app-cluster h4 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-primary);
}

.felt-app-cluster__items {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.felt-app-cluster__item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px;
  background: rgba(255, 255, 255, 0.02);
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}

.felt-app-cluster__item:hover {
  background: rgba(255, 255, 255, 0.04);
}

.felt-app-cluster__item-dot {
  flex-shrink: 0;
  width: 6px;
  height: 6px;
  margin-top: 7px;
  border-radius: 50%;
  background: var(--accent-heat);
}

.felt-app-cluster__item h5 {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.felt-app-cluster__item p {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  line-height: 1.5;
}

/* --- Comparison Section --- */
.felt-comparison__visual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  margin-top: 48px;
  margin-bottom: 48px;
}

.felt-comparison__thickness {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
}

.felt-comparison__thickness h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.felt-thickness__bars {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.felt-thickness__bar {
  display: flex;
  align-items: center;
  gap: 16px;
}

.felt-thickness__bar-label {
  flex-shrink: 0;
  width: 120px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-align: right;
}

.felt-thickness__bar-fill {
  height: 32px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 12px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: #fff;
  transition: width 1s cubic-bezier(0.4, 0, 0.2, 1);
}

.felt-thickness__bar-fill--stone {
  width: 100%;
  background: linear-gradient(90deg, #4A5568, #718096);
}

.felt-thickness__bar-fill--glass {
  width: 85%;
  background: linear-gradient(90deg, #4A5568, #718096);
}

.felt-thickness__bar-fill--levron {
  width: 33%;
  background: var(--gradient-heat);
  box-shadow: 0 0 20px rgba(232, 81, 45, 0.3);
}

/* Radar Chart */
.felt-comparison__radar {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.felt-comparison__radar h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.felt-radar__chart {
  width: 100%;
  max-width: 320px;
  aspect-ratio: 1;
}

.felt-radar__legend {
  display: flex;
  gap: 24px;
  margin-top: 20px;
}

.felt-radar__legend-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.felt-radar__legend-color {
  width: 12px;
  height: 12px;
  border-radius: 2px;
}

.felt-radar__legend-color--levron {
  background: var(--accent-heat);
}

.felt-radar__legend-color--conventional {
  background: #4A5568;
}

/* --- Fire & Moisture Section --- */
.felt-fire__grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 64px;
  align-items: center;
}

.felt-fire__visual {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.felt-fire__visual img {
  width: 100%;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-subtle);
}

.felt-fire__blocks {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 32px;
}

.felt-fire__block {
  padding: 20px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.felt-fire__block:hover {
  border-color: var(--border-medium);
}

.felt-fire__block h5 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.felt-fire__block p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.felt-fire__metric {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
  padding: 12px 16px;
  background: rgba(232, 81, 45, 0.06);
  border-radius: var(--radius-sm);
}

.felt-fire__metric-highlight {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--accent-heat-light);
}

.felt-fire__metric-vs {
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.felt-fire__metric-compare {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-tertiary);
}

/* --- Dual Property Panels --- */
.felt-dual__panels {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 48px;
}

.felt-dual__panel {
  padding: 32px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
  transition: all var(--transition-base);
}

.felt-dual__panel::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
}

.felt-dual__panel--fire::before {
  background: linear-gradient(180deg, #E8512D, #F59E0B);
}

.felt-dual__panel--moisture::before {
  background: linear-gradient(180deg, #3B82F6, #60A5FA);
}

.felt-dual__panel:hover {
  border-color: var(--border-medium);
  transform: translateY(-2px);
}

.felt-dual__panel-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.felt-dual__panel h4 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.felt-dual__panel p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.felt-dual__panel-metric {
  margin-top: 16px;
  padding: 12px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 600;
}

.felt-dual__panel--fire .felt-dual__panel-metric {
  color: var(--accent-heat-light);
}

.felt-dual__panel--moisture .felt-dual__panel-metric {
  color: var(--accent-cool-light);
}

/* --- Lightweight / Long-Life Section --- */
.felt-value__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.felt-value__card {
  padding: 32px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  text-align: center;
  transition: all var(--transition-base);
}

.felt-value__card:hover {
  border-color: var(--border-medium);
  transform: translateY(-3px);
  box-shadow: var(--shadow-card);
}

.felt-value__card-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.felt-value__card h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.felt-value__card p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.felt-value__card-metric {
  margin-top: 16px;
  padding: 10px;
  background: rgba(232, 81, 45, 0.06);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-heat-light);
}

/* --- Why Levron Company Section --- */
.felt-company__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.felt-company__visual img {
  width: 100%;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-subtle);
}

.felt-company__pillars {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 32px;
}

.felt-company__pillar {
  padding: 20px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.felt-company__pillar:hover {
  border-color: var(--border-medium);
  background: rgba(255, 255, 255, 0.04);
}

.felt-company__pillar-number {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  color: var(--accent-heat);
  margin-bottom: 8px;
}

.felt-company__pillar h5 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.felt-company__pillar p {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  line-height: 1.5;
}

/* --- Validation / Support --- */
.felt-validation__flow {
  display: flex;
  gap: 0;
  margin-top: 48px;
  position: relative;
}

.felt-validation__step {
  flex: 1;
  text-align: center;
  padding: 32px 20px;
  position: relative;
}

.felt-validation__step-number {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(232, 81, 45, 0.1);
  border: 2px solid rgba(232, 81, 45, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent-heat-light);
}

.felt-validation__step-line {
  position: absolute;
  top: 56px;
  right: -50%;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, rgba(232, 81, 45, 0.2), rgba(232, 81, 45, 0.05));
  z-index: 0;
}

.felt-validation__step:last-child .felt-validation__step-line {
  display: none;
}

.felt-validation__step h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.felt-validation__step p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 200px;
  margin: 0 auto;
}

/* --- Resource Hub --- */
.felt-resources__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.felt-resource {
  padding: 28px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

.felt-resource:hover {
  border-color: var(--border-medium);
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

.felt-resource__icon {
  font-size: 1.5rem;
  margin-bottom: 14px;
}

.felt-resource h5 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.felt-resource p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.felt-resource__link {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--accent-heat-light);
  transition: color var(--transition-fast);
}

.felt-resource__link:hover {
  color: var(--accent-heat);
}

/* --- FAQ --- */
.felt-faq {
  margin-top: 64px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.felt-faq__title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-primary);
  padding: 28px 32px;
  border-bottom: 1px solid var(--border-subtle);
  background: rgba(255, 255, 255, 0.02);
}

.felt-faq__items {
  padding: 0;
}

.felt-faq__item {
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
}

.felt-faq__item:last-child {
  border-bottom: none;
}

.felt-faq__item summary {
  padding: 20px 32px;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  transition: background var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.felt-faq__item summary::-webkit-details-marker {
  display: none;
}

.felt-faq__item summary::after {
  content: '+';
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--text-tertiary);
  transition: transform var(--transition-base);
}

.felt-faq__item[open] summary::after {
  content: '−';
  color: var(--accent-heat-light);
}

.felt-faq__item summary:hover {
  background: rgba(255, 255, 255, 0.02);
}

.felt-faq__item p {
  padding: 0 32px 20px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Final CTA Paths --- */
.felt-cta__paths {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 48px;
}

.felt-cta-path {
  padding: 32px 24px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  text-align: center;
  transition: all var(--transition-base);
}

.felt-cta-path:hover {
  border-color: rgba(232, 81, 45, 0.2);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow-heat);
}

.felt-cta-path__icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  border-radius: 50%;
  background: rgba(232, 81, 45, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-heat-light);
}

.felt-cta-path__icon svg {
  width: 24px;
  height: 24px;
}

.felt-cta-path h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
}

.felt-cta-path p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
}

/* --- Sticky CTA Bar --- */
.felt-sticky-cta {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 800;
  padding: 12px 32px;
  background: rgba(10, 12, 16, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--border-subtle);
  transform: translateY(100%);
  transition: transform var(--transition-base);
}

.felt-sticky-cta.visible {
  transform: translateY(0);
}

.felt-sticky-cta__inner {
  max-width: var(--container-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.felt-sticky-cta__info {
  display: flex;
  align-items: center;
  gap: 20px;
}

.felt-sticky-cta__title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text-primary);
}

.felt-sticky-cta__meta {
  display: flex;
  gap: 16px;
}

.felt-sticky-cta__meta span {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  color: var(--text-tertiary);
}

.felt-sticky-cta__actions {
  display: flex;
  gap: 10px;
}

/* --- Comparison Bar Chart --- */
.felt-bar-chart {
  margin-top: 32px;
}

.felt-bar-chart__row {
  display: flex;
  align-items: center;
  margin-bottom: 12px;
}

.felt-bar-chart__label {
  flex-shrink: 0;
  width: 140px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-align: right;
  padding-right: 16px;
}

.felt-bar-chart__track {
  flex: 1;
  height: 28px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 4px;
  position: relative;
  overflow: hidden;
}

.felt-bar-chart__fill {
  height: 100%;
  border-radius: 4px;
  display: flex;
  align-items: center;
  padding-left: 12px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.9);
  transition: width 1.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.felt-bar-chart__fill--levron {
  background: var(--gradient-heat);
}

.felt-bar-chart__fill--conventional {
  background: linear-gradient(90deg, #374151, #4B5563);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .felt-perf__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .felt-apps__clusters {
    grid-template-columns: 1fr;
  }

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

  .felt-validation__flow {
    flex-wrap: wrap;
  }

  .felt-validation__step {
    flex: 0 0 50%;
  }

  .felt-validation__step-line {
    display: none;
  }
}

@media (max-width: 768px) {
  .felt-hero__micro-strip {
    flex-direction: column;
  }

  .felt-hero__micro-item:first-child,
  .felt-hero__micro-item:last-child {
    border-radius: var(--radius-md);
  }

  .felt-section-nav__link {
    padding: 12px 12px;
    font-size: 0.625rem;
  }

  .felt-overview__grid,
  .felt-format__grid,
  .felt-science__grid,
  .felt-fire__grid,
  .felt-company__grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .felt-perf__grid {
    grid-template-columns: 1fr;
  }

  .felt-overview__features {
    grid-template-columns: 1fr;
  }

  .felt-comparison__visual {
    grid-template-columns: 1fr;
  }

  .felt-dual__panels {
    grid-template-columns: 1fr;
  }

  .felt-value__grid {
    grid-template-columns: 1fr;
  }

  .felt-company__pillars {
    grid-template-columns: 1fr;
  }

  .felt-resources__grid {
    grid-template-columns: 1fr;
  }

  .felt-cta__paths {
    grid-template-columns: 1fr;
  }

  .felt-validation__step {
    flex: 0 0 100%;
  }

  .felt-specs__table-wrap {
    overflow-x: auto;
  }

  .felt-sticky-cta__meta {
    display: none;
  }

  .felt-sticky-cta__inner {
    gap: 16px;
  }
}