/* === Height in Inches Calculator — Premium Luxury Design === */

:root {
  --gold-50: #fffdf5;
  --gold-100: #fef9e7;
  --gold-200: #fcefc7;
  --gold-300: #f5d98a;
  --gold-400: #e8c44d;
  --gold-500: #d4a528;
  --gold-600: #b8860b;
  --gold-700: #96690a;
  --gold-800: #7a5209;
  --gold-900: #5c3d07;
  --rose-300: #f5d0d3;
  --rose-400: #e8b4b8;
  --rose-500: #d4949a;
  --white: #ffffff;
  --gray-50: #fafafa;
  --gray-100: #f4f4f5;
  --gray-200: #e4e4e7;
  --gray-300: #d4d4d8;
  --gray-400: #a1a1aa;
  --gray-500: #71717a;
  --gray-600: #52525b;
  --bg-dark: #050608;
  --bg-card: rgba(255,255,255,0.025);
  --glass: rgba(255,255,255,0.04);
  --glass-border: rgba(212,165,40,0.12);
  --glass-border-subtle: rgba(255,255,255,0.06);
  --glow-gold: rgba(212,165,40,0.3);
  --glow-rose: rgba(232,180,184,0.2);
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.5);
  --shadow-xl: 0 30px 80px rgba(0,0,0,0.6);
  --shadow-gold: 0 8px 40px rgba(212,165,40,0.15);
  --radius: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
  --transition-slow: all 0.6s cubic-bezier(0.4,0,0.2,1);
}

/* === SECTION COMMON === */
.section {
  position: relative;
  z-index: 1;
  padding: 120px 40px;
}
.section-header {
  text-align: center;
  margin-bottom: 72px;
}
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  border-radius: 50px;
  background: linear-gradient(135deg, rgba(212,165,40,0.08), rgba(232,180,184,0.04));
  border: 1px solid rgba(212,165,40,0.25);
  font-size: 0.72rem;
  color: var(--gold-400);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2.5px;
  margin-bottom: 20px;
}
.section-header h1,
.section-header h2 {
  font-family: 'Playfair Display', serif;
  font-size: clamp(2.2rem, 4.5vw, 3.4rem);
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--white);
  line-height: 1.15;
}
.section-header p {
  font-size: 1.05rem;
  color: var(--gray-400);
  max-width: 580px;
  margin: 0 auto;
  line-height: 1.7;
}

.gradient-text {
  background: linear-gradient(135deg, var(--gold-300), var(--gold-500), var(--rose-400), var(--gold-300));
  background-size: 300% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: shimmer 4s linear infinite;
}
@keyframes shimmer { 0%{background-position:0% center;} 100%{background-position:300% center;} }

/* === HERO SECTION === */
.hero-section {
  position: relative;
  z-index: 1;
  padding: 180px 40px 100px;
  text-align: center;
  overflow: hidden;
}
.hero-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(212,165,40,0.06) 0%, transparent 70%);
  pointer-events: none;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 24px;
  border-radius: 50px;
  background: linear-gradient(135deg, rgba(212,165,40,0.1), rgba(232,180,184,0.05));
  border: 1px solid rgba(212,165,40,0.3);
  font-size: 0.8rem;
  color: var(--gold-300);
  font-weight: 600;
  letter-spacing: 1px;
  margin-bottom: 32px;
  animation: fadeInUp 0.8s ease-out;
}
.hero-badge .badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold-400);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse { 0%,100%{opacity:1;transform:scale(1);} 50%{opacity:0.5;transform:scale(0.8);} }

.hero-title {
  font-family: 'Playfair Display', serif;
  font-size: clamp(2.8rem, 5.5vw, 4.2rem);
  font-weight: 700;
  color: var(--white);
  margin-bottom: 24px;
  line-height: 1.1;
  animation: fadeInUp 0.8s ease-out 0.1s both;
}
.hero-subtitle {
  font-size: 1.15rem;
  color: var(--gray-400);
  max-width: 620px;
  margin: 0 auto 40px;
  line-height: 1.8;
  animation: fadeInUp 0.8s ease-out 0.2s both;
}
.hero-cta-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease-out 0.3s both;
}
.hero-btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 36px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--gold-500), var(--gold-400), var(--gold-600));
  color: #0a0a0a;
  font-weight: 700;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  letter-spacing: 0.3px;
  box-shadow: var(--shadow-gold);
}
.hero-btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 50px rgba(212,165,40,0.35);
}
.hero-btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 36px;
  border-radius: 12px;
  background: transparent;
  color: var(--gold-300);
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid rgba(212,165,40,0.3);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}
.hero-btn-secondary:hover {
  background: rgba(212,165,40,0.08);
  border-color: var(--gold-400);
  transform: translateY(-2px);
}

/* Stats bar */
.stats-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 48px;
  margin-top: 80px;
  padding: 32px 40px;
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  border: 1px solid var(--glass-border-subtle);
  backdrop-filter: blur(20px);
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
  animation: fadeInUp 0.8s ease-out 0.5s both;
}
.stat-item {
  text-align: center;
}
.stat-number {
  font-family: 'Playfair Display', serif;
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--gold-400);
  display: block;
}
.stat-label {
  font-size: 0.78rem;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: 4px;
}
.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--glass-border);
}

/* === CALCULATOR === */
.calculator-wrapper {
  max-width: 920px;
  margin: 0 auto;
  background: linear-gradient(165deg, rgba(15,15,20,0.95), rgba(8,8,12,0.98));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: 56px;
  backdrop-filter: blur(30px);
  box-shadow: var(--shadow-lg), inset 0 1px 0 rgba(212,165,40,0.08);
  position: relative;
  overflow: hidden;
}
.calculator-wrapper::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--gold-500), var(--rose-400), var(--gold-500), transparent);
}
.calculator-wrapper::after {
  content: '';
  position: absolute;
  top: -200px;
  right: -200px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(212,165,40,0.03) 0%, transparent 70%);
  pointer-events: none;
}

.calc-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 44px;
  background: rgba(255,255,255,0.02);
  border-radius: 14px;
  padding: 5px;
  border: 1px solid var(--glass-border-subtle);
}
.calc-tab {
  flex: 1;
  padding: 14px 20px;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  background: transparent;
  color: var(--gray-500);
  font-weight: 600;
  font-size: 0.88rem;
  transition: var(--transition);
  font-family: 'Inter', sans-serif;
  position: relative;
}
.calc-tab.active {
  background: linear-gradient(135deg, var(--gold-600), var(--gold-500));
  color: #0a0a0a;
  box-shadow: var(--shadow-gold);
}
.calc-tab:hover:not(.active) {
  color: var(--gold-300);
  background: rgba(212,165,40,0.06);
}

.calc-panel { display: none; }
.calc-panel.active { display: block; animation: fadeInUp 0.4s ease-out; }

.converter-label {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--gold-300);
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 2px;
}

/* === UNIT PILLS === */
.unit-pills {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}
.unit-pill {
  padding: 10px 20px;
  border-radius: 10px;
  border: 1px solid var(--glass-border-subtle);
  background: transparent;
  color: var(--gray-400);
  font-weight: 600;
  font-size: 0.82rem;
  cursor: pointer;
  transition: var(--transition);
  font-family: 'Inter', sans-serif;
}
.unit-pill:hover {
  color: var(--gold-300);
  border-color: rgba(212,165,40,0.3);
  background: rgba(212,165,40,0.05);
}
.unit-pill.active {
  background: linear-gradient(135deg, var(--gold-600), var(--gold-500));
  color: #0a0a0a;
  border-color: transparent;
  box-shadow: 0 4px 20px var(--glow-gold);
  font-weight: 700;
}

/* === UNIT PANELS === */
.unit-panel { display: none; margin-bottom: 24px; }
.unit-panel.active { display: block; animation: fadeInUp 0.3s ease-out; }

/* === INPUT === */
.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 32px;
}
.input-group { display: flex; flex-direction: column; gap: 10px; }
.input-group label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--gray-300);
  letter-spacing: 0.5px;
}
.input-field {
  padding: 16px 20px;
  border-radius: 12px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--glass-border-subtle);
  color: var(--white);
  font-size: 1rem;
  font-family: 'Inter', sans-serif;
  transition: var(--transition);
  outline: none;
}
.input-field:focus {
  border-color: var(--gold-500);
  box-shadow: 0 0 0 3px rgba(212,165,40,0.12), 0 0 20px rgba(212,165,40,0.05);
  background: rgba(212,165,40,0.02);
}
.input-field::placeholder { color: var(--gray-600); }

.calc-btn {
  width: 100%;
  padding: 18px;
  border-radius: 14px;
  border: none;
  cursor: pointer;
  background: linear-gradient(135deg, var(--gold-600), var(--gold-500), var(--gold-400));
  color: #0a0a0a;
  font-weight: 700;
  font-size: 1rem;
  transition: var(--transition);
  box-shadow: var(--shadow-gold);
  font-family: 'Inter', sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  letter-spacing: 0.3px;
}
.calc-btn:hover { transform: translateY(-2px); box-shadow: 0 12px 50px rgba(212,165,40,0.3); }
.calc-btn:active { transform: translateY(0); }

/* === RESULTS === */
.result-card {
  margin-top: 36px;
  padding: 36px;
  border-radius: var(--radius-lg);
  background: linear-gradient(145deg, rgba(212,165,40,0.06), rgba(232,180,184,0.03));
  border: 1px solid rgba(212,165,40,0.2);
  text-align: center;
  display: none;
  animation: fadeInUp 0.5s ease-out;
  position: relative;
}
.result-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold-500), transparent);
}
.result-card.show { display: block; }
.result-heading {
  font-family: 'Playfair Display', serif;
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--white);
}
.result-highlight { color: var(--gold-400); }
.results-table-wrap { overflow-x: auto; }
.results-table { width: 100%; border-collapse: collapse; }
.results-table th {
  text-align: left;
  padding: 14px 18px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--gray-400);
  border-bottom: 1px solid rgba(212,165,40,0.1);
  white-space: nowrap;
}
.results-table td {
  padding: 14px 18px;
  font-size: 1rem;
  border-bottom: 1px solid rgba(212,165,40,0.06);
}
.res-val {
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  color: var(--gold-300);
  transition: all 0.4s ease;
  font-size: 1.05rem;
}
.result-actions {
  display: flex;
  gap: 12px;
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid rgba(212,165,40,0.1);
}
.result-action-btn {
  padding: 10px 22px;
  border-radius: 10px;
  border: 1px solid var(--glass-border-subtle);
  background: transparent;
  color: var(--gray-400);
  font-weight: 600;
  font-size: 0.82rem;
  cursor: pointer;
  transition: var(--transition);
  font-family: 'Inter', sans-serif;
}
.result-action-btn:hover {
  border-color: var(--gold-500);
  color: var(--gold-300);
  background: rgba(212,165,40,0.06);
}

/* === ARITHMETIC CALCULATOR === */
.calc-sub-desc {
  font-size: 0.88rem;
  color: var(--gray-500);
  margin-bottom: 28px;
  font-style: italic;
}
.arith-section {
  margin-bottom: 20px;
  padding: 24px;
  border-radius: var(--radius);
  background: rgba(255,255,255,0.015);
  border: 1px solid var(--glass-border-subtle);
}
.arith-label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--gold-400);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 14px;
}
.operation-row {
  display: flex;
  justify-content: center;
  margin-bottom: 20px;
}
.operation-select {
  padding: 14px 28px;
  border-radius: 12px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--glass-border-subtle);
  color: var(--white);
  font-size: 1rem;
  font-weight: 600;
  font-family: 'Inter', sans-serif;
  cursor: pointer;
  transition: var(--transition);
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%23d4a528' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 48px;
  min-width: 200px;
}
.operation-select:focus {
  border-color: var(--gold-500);
  box-shadow: 0 0 0 3px rgba(212,165,40,0.12);
}
.operation-select option { background: var(--bg-dark); color: var(--white); }

.arith-btn-row { display: flex; gap: 12px; margin-bottom: 0; }
.calc-btn-half { flex: 1; }
.calc-btn-outline {
  background: transparent !important;
  border: 1px solid var(--glass-border) !important;
  color: var(--gold-300) !important;
  box-shadow: none !important;
}
.calc-btn-outline:hover {
  border-color: var(--gold-500) !important;
  background: rgba(212,165,40,0.08) !important;
}

.arith-results { padding: 8px 0; }
.arith-result-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(212,165,40,0.06);
}
.arith-result-row:last-child { border-bottom: none; }
.arith-eq {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--gold-500);
  width: 24px;
  text-align: center;
  flex-shrink: 0;
}
.arith-res-val {
  font-family: 'Playfair Display', serif;
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--gold-300);
  transition: all 0.4s ease;
}

/* === HEIGHT CHARTS === */
.chart-filter-row {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
}
.chart-filter-label { font-size: 0.85rem; color: var(--gray-400); font-weight: 500; }
.chart-table-wrap {
  max-height: 500px;
  overflow-y: auto;
  border-radius: var(--radius);
  border: 1px solid var(--glass-border-subtle);
}
.chart-table-wrap::-webkit-scrollbar { width: 6px; }
.chart-table-wrap::-webkit-scrollbar-track { background: rgba(255,255,255,0.01); }
.chart-table-wrap::-webkit-scrollbar-thumb { background: var(--gold-600); border-radius: 3px; }
.chart-table-wrap .conv-table { margin: 0; }
.chart-table-wrap .conv-table thead th {
  position: sticky;
  top: 0;
  z-index: 2;
  background: rgba(20,16,8,0.95);
  backdrop-filter: blur(10px);
}

/* === INTERACTIVE DIAGRAM === */
.diagram-container {
  max-width: 1100px;
  margin: 0 auto;
  position: relative;
}
.diagram-box {
  background: linear-gradient(165deg, rgba(15,15,20,0.95), rgba(8,8,12,0.98));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: 56px;
  backdrop-filter: blur(30px);
  box-shadow: var(--shadow-lg);
  position: relative;
  overflow: hidden;
}
.diagram-box::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--gold-400), var(--rose-400), var(--gold-400), transparent);
}

/* Diagram flow steps */
.diagram-flow {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 0;
  flex-wrap: nowrap;
  position: relative;
  padding: 20px 0;
}
.diagram-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 28px 20px;
  border-radius: var(--radius);
  flex: 1;
  min-width: 150px;
  background: rgba(255,255,255,0.015);
  border: 1px solid transparent;
  transition: var(--transition);
  cursor: pointer;
  position: relative;
}
.diagram-step:hover,
.diagram-step.active {
  background: rgba(212,165,40,0.06);
  border-color: rgba(212,165,40,0.25);
  transform: translateY(-6px);
  box-shadow: 0 12px 40px rgba(212,165,40,0.1);
}
.step-icon {
  width: 68px;
  height: 68px;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(212,165,40,0.15), rgba(212,165,40,0.05));
  border: 1px solid rgba(212,165,40,0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.7rem;
  margin-bottom: 18px;
  transition: var(--transition);
}
.diagram-step.active .step-icon {
  transform: scale(1.1);
  background: linear-gradient(135deg, rgba(212,165,40,0.25), rgba(212,165,40,0.1));
  box-shadow: 0 8px 30px var(--glow-gold);
  border-color: rgba(212,165,40,0.4);
}
.step-num {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: rgba(212,165,40,0.2);
  border: 1px solid rgba(212,165,40,0.3);
  font-size: 0.7rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gold-300);
}
.step-title { font-weight: 700; font-size: 0.95rem; margin-bottom: 6px; color: var(--white); }
.step-desc { font-size: 0.78rem; color: var(--gray-500); line-height: 1.4; }
.diagram-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gold-500);
  font-size: 1.4rem;
  min-width: 36px;
  animation: arrowPulse 2s ease-in-out infinite;
}
@keyframes arrowPulse { 0%,100%{opacity:0.3;} 50%{opacity:1;} }

.diagram-detail {
  margin-top: 36px;
  padding: 32px;
  border-radius: var(--radius);
  background: rgba(212,165,40,0.04);
  border: 1px solid rgba(212,165,40,0.15);
  min-height: 120px;
  transition: var(--transition);
}
.diagram-detail h4 {
  font-family: 'Playfair Display', serif;
  font-size: 1.15rem;
  margin-bottom: 12px;
  color: var(--gold-300);
}
.diagram-detail p { font-size: 0.92rem; color: var(--gray-400); line-height: 1.8; }
.diagram-detail .formula-box {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 10px;
  background: rgba(0,0,0,0.4);
  border: 1px solid rgba(212,165,40,0.2);
  font-family: 'JetBrains Mono', 'Courier New', monospace;
  color: var(--gold-300);
  font-size: 0.88rem;
  margin-top: 14px;
}

/* === VISUAL HEIGHT DIAGRAM (SVG) === */
.visual-diagram-section {
  position: relative;
  z-index: 1;
  padding: 120px 40px;
}
.visual-diagram-wrapper {
  max-width: 1000px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 60px;
  align-items: center;
}
.visual-diagram-svg {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}
.visual-diagram-svg svg {
  width: 100%;
  max-width: 320px;
  height: auto;
}
.visual-diagram-controls {
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.visual-diagram-card {
  background: linear-gradient(165deg, rgba(15,15,20,0.95), rgba(8,8,12,0.98));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 40px;
  position: relative;
  overflow: hidden;
}
.visual-diagram-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold-500), transparent);
}
.visual-diagram-title {
  font-family: 'Playfair Display', serif;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 8px;
}
.visual-diagram-desc {
  font-size: 0.9rem;
  color: var(--gray-400);
  margin-bottom: 28px;
  line-height: 1.6;
}
.visual-input-row {
  display: flex;
  gap: 16px;
  margin-bottom: 20px;
}
.visual-input-group {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.visual-input-group label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--gray-400);
  text-transform: uppercase;
  letter-spacing: 1px;
}
.visual-input {
  padding: 14px 18px;
  border-radius: 10px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--glass-border-subtle);
  color: var(--white);
  font-size: 1.1rem;
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  outline: none;
  transition: var(--transition);
  width: 100%;
}
.visual-input:focus {
  border-color: var(--gold-500);
  box-shadow: 0 0 0 3px rgba(212,165,40,0.1);
}
.visual-result-display {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px 24px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(212,165,40,0.1), rgba(212,165,40,0.03));
  border: 1px solid rgba(212,165,40,0.25);
}
.visual-result-label {
  font-size: 0.78rem;
  color: var(--gray-400);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  font-weight: 600;
}
.visual-result-value {
  font-family: 'Playfair Display', serif;
  font-size: 2rem;
  font-weight: 700;
  color: var(--gold-400);
}
.visual-result-unit {
  font-size: 0.9rem;
  color: var(--gray-400);
  margin-left: 4px;
}
.visual-breakdown {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 20px;
}
.visual-breakdown-item {
  padding: 14px 16px;
  border-radius: 10px;
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--glass-border-subtle);
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.visual-breakdown-label {
  font-size: 0.72rem;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 1px;
}
.visual-breakdown-value {
  font-family: 'Playfair Display', serif;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--gold-300);
}

/* Ruler markings animation */
.ruler-mark {
  transition: var(--transition-slow);
}
.ruler-mark.active {
  stroke: var(--gold-400);
  stroke-width: 2;
}

/* Live demo */
.live-demo {
  margin-top: 36px;
  padding: 32px;
  border-radius: var(--radius);
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--glass-border-subtle);
}
.live-demo h4 {
  font-family: 'Playfair Display', serif;
  font-size: 1rem;
  margin-bottom: 18px;
  color: var(--gold-300);
}
.demo-row { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.demo-input {
  padding: 12px 16px;
  border-radius: 10px;
  width: 85px;
  text-align: center;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--glass-border-subtle);
  color: var(--white);
  font-size: 1.05rem;
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  outline: none;
  transition: var(--transition);
}
.demo-input:focus { border-color: var(--gold-500); box-shadow: 0 0 0 3px rgba(212,165,40,0.1); }
.demo-label { font-size: 0.85rem; color: var(--gray-500); font-weight: 500; }
.demo-equals { font-size: 1.4rem; color: var(--gold-500); font-weight: 700; margin: 0 6px; }
.demo-result {
  padding: 12px 24px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--gold-600), var(--gold-500));
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  font-size: 1.15rem;
  min-width: 110px;
  text-align: center;
  color: #0a0a0a;
  box-shadow: var(--shadow-gold);
}

/* === FEATURES === */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 1100px;
  margin: 0 auto;
}
.feature-card {
  padding: 40px 32px;
  border-radius: var(--radius-lg);
  background: linear-gradient(165deg, rgba(15,15,20,0.9), rgba(8,8,12,0.95));
  border: 1px solid var(--glass-border-subtle);
  backdrop-filter: blur(10px);
  transition: var(--transition);
  cursor: default;
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(212,165,40,0.3), transparent);
  opacity: 0;
  transition: var(--transition);
}
.feature-card:hover::before { opacity: 1; }
.feature-card:hover {
  transform: translateY(-8px);
  border-color: rgba(212,165,40,0.2);
  box-shadow: 0 24px 60px rgba(0,0,0,0.4), 0 0 60px rgba(212,165,40,0.05);
}
.feature-icon {
  width: 60px;
  height: 60px;
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(212,165,40,0.12), rgba(232,180,184,0.06));
  border: 1px solid rgba(212,165,40,0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 24px;
  transition: var(--transition);
}
.feature-card:hover .feature-icon {
  transform: scale(1.1);
  box-shadow: 0 8px 30px var(--glow-gold);
  border-color: rgba(212,165,40,0.4);
}
.feature-card h3 {
  font-family: 'Playfair Display', serif;
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--white);
}
.feature-card p { font-size: 0.88rem; color: var(--gray-500); line-height: 1.7; }

/* === CONVERSION TABLE === */
.table-wrapper {
  max-width: 920px;
  margin: 0 auto;
  background: linear-gradient(165deg, rgba(15,15,20,0.95), rgba(8,8,12,0.98));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-lg);
}
.conv-table { width: 100%; border-collapse: collapse; }
.conv-table thead { background: rgba(212,165,40,0.08); }
.conv-table th {
  padding: 18px 24px;
  text-align: left;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--gold-400);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  border-bottom: 1px solid rgba(212,165,40,0.12);
}
.conv-table td {
  padding: 16px 24px;
  font-size: 0.93rem;
  color: var(--gray-300);
  border-bottom: 1px solid var(--glass-border-subtle);
  transition: var(--transition);
}
.conv-table tr:hover td { background: rgba(212,165,40,0.03); color: var(--white); }
.conv-table td:last-child { color: var(--gold-300); font-weight: 600; font-family: 'Playfair Display', serif; }

/* === CONTENT SECTIONS === */
.content-sections {
  padding: 80px 40px;
}
.content-wrapper {
  max-width: 920px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 40px;
}
.content-wrapper .content-card {
  background: linear-gradient(165deg, rgba(15,15,20,0.9), rgba(8,8,12,0.95));
  border: 1px solid var(--glass-border-subtle);
  border-radius: var(--radius-lg);
  padding: 48px;
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
}
.content-wrapper .content-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(212,165,40,0.2), transparent);
}
.content-wrapper .content-card h2 {
  font-family: 'Playfair Display', serif;
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 20px;
}
.content-wrapper .content-card h3 {
  font-family: 'Playfair Display', serif;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--gold-300);
  margin-bottom: 16px;
  margin-top: 28px;
}
.content-wrapper .content-card h3:first-child {
  margin-top: 0;
}
.content-wrapper .content-card p {
  font-size: 0.95rem;
  color: var(--gray-300);
  line-height: 1.85;
  margin-bottom: 16px;
}
.content-wrapper .content-card ul,
.content-wrapper .content-card ol {
  padding-left: 24px;
  margin-bottom: 18px;
}
.content-wrapper .content-card li {
  font-size: 0.93rem;
  color: var(--gray-300);
  line-height: 1.85;
  margin-bottom: 8px;
}
.content-wrapper .content-card li::marker {
  color: var(--gold-500);
}
.content-wrapper .content-card strong {
  color: var(--white);
}
.content-wrapper .formula-box {
  display: block;
  padding: 18px 28px;
  border-radius: 12px;
  background: rgba(0,0,0,0.4);
  border: 1px solid rgba(212,165,40,0.2);
  font-family: 'JetBrains Mono', 'Courier New', monospace;
  color: var(--gold-300);
  font-size: 0.92rem;
  margin: 18px 0;
  line-height: 1.7;
}

/* === FAQ === */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.faq-item {
  background: rgba(255,255,255,0.015);
  border: 1px solid var(--glass-border-subtle);
  border-radius: 14px;
  overflow: hidden;
  transition: var(--transition);
}
.faq-item[open] {
  border-color: rgba(212,165,40,0.25);
  background: rgba(212,165,40,0.03);
}
.faq-question {
  padding: 20px 28px;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--white);
  cursor: pointer;
  list-style: none;
  transition: var(--transition);
}
.faq-question::-webkit-details-marker { display: none; }
.faq-question::before {
  content: '+';
  float: right;
  font-size: 1.3rem;
  color: var(--gold-500);
  font-weight: 700;
  transition: var(--transition);
}
.faq-item[open] .faq-question::before {
  content: '\2212';
  color: var(--gold-400);
}
.faq-question:hover { color: var(--gold-300); }
.faq-answer {
  padding: 0 28px 20px;
}
.faq-answer p {
  font-size: 0.9rem;
  color: var(--gray-400);
  line-height: 1.8;
  margin-bottom: 10px;
}
.faq-answer ul {
  padding-left: 20px;
  margin-bottom: 10px;
}
.faq-answer li {
  font-size: 0.9rem;
  color: var(--gray-400);
  line-height: 1.8;
  margin-bottom: 4px;
}

/* === SCROLL REVEAL === */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

/* === RESPONSIVE === */
@media (max-width: 1024px) {
  .visual-diagram-wrapper {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .visual-diagram-svg { order: -1; }
}

@media (max-width: 768px) {
  .section { padding: 80px 20px; }
  .hero-section { padding: 140px 20px 80px; }
  .input-grid { grid-template-columns: 1fr; }
  .calculator-wrapper { padding: 32px 20px; }
  .features-grid { grid-template-columns: 1fr; }
  .diagram-flow { flex-direction: column; align-items: center; }
  .diagram-arrow { transform: rotate(90deg); }
  .unit-pills { flex-wrap: wrap; }
  .unit-pill { font-size: 0.75rem; padding: 8px 14px; }
  .results-table th,
  .results-table td { padding: 10px 12px; font-size: 0.85rem; }
  .arith-btn-row { flex-direction: column; }
  .arith-btn-row .calc-btn-half { width: 100%; }
  .chart-filter-row { flex-direction: column; align-items: stretch; }
  .chart-table-wrap { overflow-x: auto; }
  .content-sections { padding: 40px 20px; }
  .content-wrapper .content-card { padding: 28px 20px; }
  .demo-row { flex-direction: column; align-items: stretch; }
  .diagram-box { padding: 28px 20px; }
  .stats-bar { flex-direction: column; gap: 24px; padding: 28px 20px; }
  .stat-divider { width: 40px; height: 1px; }
  .visual-diagram-wrapper { padding: 0; }
  .visual-diagram-card { padding: 28px 20px; }
  .visual-input-row { flex-direction: column; gap: 12px; }
  .visual-breakdown { grid-template-columns: 1fr; }
  .hero-title { font-size: clamp(2rem, 6vw, 3rem); }
  .visual-diagram-section { padding: 80px 20px; }
}