:root {
  --primary: #2563EB;
  --primary-dark: #1D4ED8;
  --primary-light: #93C5FD;
  --bg: #F8FAFC;
  --bg-card: #FFFFFF;
  --bg-input: #F1F5F9;
  --text: #1E293B;
  --text-dim: #64748B;
  --success: #10B981;
  --error: #EF4444;
  --border: #E2E8F0;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
  --radius: 12px;
  --transition-speed: 0.2s;
  --transition-timing: cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  font-family: 'Inter', -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main { flex: 1; }

.container { max-width: 960px; margin: 0 auto; padding: 0 20px; }

/* Header */
.header {
  background: white;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--text);
  font-weight: 800;
  font-size: 1.2rem;
}

.nav {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.nav a {
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 500;
  padding: 4px 8px;
  border-radius: 6px;
  transition: all var(--transition-speed) var(--transition-timing);
  position: relative;
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--primary);
  transform: translateX(-50%);
  transition: width var(--transition-speed) var(--transition-timing);
}

.nav a:hover {
  color: var(--primary);
  background: #EFF6FF;
}

.nav a:hover::after {
  width: 80%;
}

.nav a.active {
  color: var(--primary);
  background: #EFF6FF;
}

.nav a.active::after {
  width: 80%;
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-left: 8px;
}

.lang-switch a {
  padding: 2px 6px;
  border-radius: 4px;
}

.lang-switch a.active { background: var(--primary); color: white; }

.lang-switch span { color: var(--border); }

.nav-toggle { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; }

/* Breadcrumb Navigation */
.breadcrumb {
  background: white;
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
  font-size: 0.85rem;
}

.breadcrumb ol {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.breadcrumb li {
  display: flex;
  align-items: center;
  color: var(--text-dim);
}

.breadcrumb li:not(:last-child)::after {
  content: '›';
  margin-left: 8px;
  color: var(--border);
  font-size: 1.2rem;
}

.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-speed) var(--transition-timing);
}

.breadcrumb a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

.breadcrumb li:last-child {
  color: var(--text);
  font-weight: 500;
}

/* Hero */
.hero {
  text-align: center;
  padding: 50px 0 30px;
  background: linear-gradient(135deg, #EFF6FF 0%, #DBEAFE 100%);
}

.hero-title {
  font-size: 3rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 1.5rem;
  line-height: 1.2;
}
.hero-subtitle {
  font-size: 1.3rem;
  color: #64748b;
  max-width: 700px;
  margin: 0 auto 2rem;
  line-height: 1.6;
}

/* Hero CTA Buttons */
.hero-cta-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin: 2rem 0;
}

.btn-hero-primary {
  background: var(--primary);
  color: white;
  padding: 1.25rem 2.5rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
  transition: all 0.3s;
  display: inline-block;
}

.btn-hero-secondary {
  background: white;
  color: var(--primary);
  padding: 1.25rem 2.5rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  border: 2px solid var(--primary);
  transition: all 0.3s;
  display: inline-block;
}

/* Trust Signals */
.trust-signals {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1.5rem;
  max-width: 800px;
  margin: 3rem auto;
  flex-wrap: wrap;
  gap: 16px;
  margin: 24px 0 16px;
}

.trust-badge {
  padding: 1.5rem;
  background: white;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  text-align: center;
  padding: 8px 16px;
  background: white;
  border: 1px solid #E5E7EB;
  border-radius: 24px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text);
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.trust-icon {
  font-size: 2.5rem;
  display: block;
  margin-bottom: 0.75rem;
}

.trust-text {
  font-weight: 600;
  display: block;
  margin-bottom: 0.25rem;
  color: var(--text);
}

.trust-desc {
  font-size: 0.85rem;
  color: #64748b;
  display: block;
}

/* Social Proof */
.social-proof {
  margin-top: 16px;
}

.usage-stats {
  color: var(--text-dim);
  font-size: 0.9rem;
}

.usage-stats strong {
  color: var(--primary);
  font-weight: 700;
  font-size: 1.1rem;
}

/* Tools Grid */
.tools-grid-section { padding: 40px 0; }

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.tool-card {
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-decoration: none;
  color: var(--text);
  transition: all var(--transition-speed) var(--transition-timing);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-speed) var(--transition-timing);
}

.tool-card:hover {
  border-color: var(--primary);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.15);
  transform: translateY(-4px);
}

.tool-card:hover::before {
  transform: scaleX(1);
}

.tool-card:active {
  transform: translateY(-2px);
}

.tool-icon {
  font-size: 2rem;
  margin-bottom: 12px;
  display: inline-block;
  transition: transform var(--transition-speed) var(--transition-timing);
}

.tool-card:hover .tool-icon {
  transform: scale(1.1) rotate(5deg);
}

.tool-card h2 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
  transition: color var(--transition-speed) var(--transition-timing);
}

.tool-card:hover h2 {
  color: var(--primary);
}

.tool-card p {
  font-size: 0.88rem;
  color: var(--text-dim);
  flex: 1;
  margin-bottom: 12px;
}

.tool-link {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap var(--transition-speed) var(--transition-timing);
}

.tool-card:hover .tool-link {
  gap: 8px;
}

/* Tool Page */
.tool-page { padding: 30px 0; }

.tool-header {
  text-align: center;
  margin-bottom: 30px;
}

.tool-header h1 { font-size: 1.6rem; font-weight: 700; margin-bottom: 8px; }
.tool-header p { color: var(--text-dim); font-size: 0.95rem; }

.calc-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
  align-items: start;
}

.calc-form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.form-group {
  margin-bottom: 18px;
  position: relative;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text);
  transition: color var(--transition-speed) var(--transition-timing);
}

/* Input wrapper for icons */
.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.input-icon {
  position: absolute;
  left: 12px;
  pointer-events: none;
  opacity: 0.5;
  transition: opacity var(--transition-speed) var(--transition-timing);
}

.input-wrapper input {
  padding-left: 36px !important;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 10px 14px;
  border: 2px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  background: var(--bg-input);
  transition: all var(--transition-speed) var(--transition-timing);
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  background: white;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
  transform: translateY(-1px);
}

.form-group input:focus + .input-icon {
  opacity: 1;
  color: var(--primary);
}

/* Validation feedback */
.form-group.valid input {
  border-color: var(--success);
  background: rgba(16, 185, 129, 0.05);
}

.form-group.invalid input {
  border-color: var(--error);
  background: rgba(239, 68, 68, 0.05);
}

.validation-icon {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  opacity: 0;
  transition: opacity var(--transition-speed) var(--transition-timing);
}

.form-group.valid .validation-icon.check,
.form-group.invalid .validation-icon.cross {
  opacity: 1;
}

.validation-icon.check { color: var(--success); }
.validation-icon.cross { color: var(--error); }

/* Smart number formatting hint */
.input-hint {
  position: absolute;
  right: 12px;
  bottom: -18px;
  font-size: 0.75rem;
  color: var(--text-dim);
  opacity: 0;
  transition: opacity var(--transition-speed) var(--transition-timing);
}

.form-group:focus-within .input-hint {
  opacity: 1;
}

.term-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.form-actions {
  display: flex;
  gap: 10px;
  margin-top: 20px;
}

.btn-primary {
  flex: 1;
  padding: 12px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: all var(--transition-speed) var(--transition-timing);
  position: relative;
  overflow: hidden;
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-primary:active {
  transform: translateY(0) scale(0.98);
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.3);
}

/* Ripple effect */
.btn-primary::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn-primary:active::after {
  width: 300px;
  height: 300px;
}

.btn-primary:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.btn-secondary {
  padding: 12px 20px;
  background: var(--bg-input);
  color: var(--text-dim);
  border: 2px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  cursor: pointer;
  font-family: inherit;
  transition: all var(--transition-speed) var(--transition-timing);
}

.btn-secondary:hover {
  background: var(--border);
  border-color: var(--text-dim);
  transform: translateY(-1px);
}

.btn-secondary:active {
  transform: translateY(0) scale(0.98);
}

/* Results */
.calc-results {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  opacity: 0;
  transform: translateY(20px);
  animation: slideInUp 0.4s var(--transition-timing) forwards;
}

@keyframes slideInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Skeleton loading */
.calc-results.loading {
  animation: none;
  opacity: 1;
}

.skeleton {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: 4px;
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.result-summary { margin-bottom: 20px; }

.result-big {
  text-align: center;
  padding: 20px;
  background: linear-gradient(135deg, #EFF6FF, #DBEAFE);
  border-radius: var(--radius);
  margin-bottom: 16px;
  position: relative;
  overflow: hidden;
}

.result-big::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.1) 0%, transparent 70%);
  animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(0.8); opacity: 0.5; }
  50% { transform: scale(1.2); opacity: 0.8; }
}

.result-label {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
  position: relative;
  z-index: 1;
}

.result-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary-dark);
  position: relative;
  z-index: 1;
  display: inline-block;
  animation: countUp 0.8s var(--transition-timing);
}

@keyframes countUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.result-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.result-stat {
  padding: 12px;
  background: var(--bg-input);
  border-radius: 8px;
  text-align: center;
  transition: all var(--transition-speed) var(--transition-timing);
  animation: fadeIn 0.5s var(--transition-timing) backwards;
}

.result-stat:nth-child(1) { animation-delay: 0.1s; }
.result-stat:nth-child(2) { animation-delay: 0.2s; }

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.result-stat:hover {
  background: white;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.result-value-sm {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  display: inline-block;
}

/* Savings badge */
.savings-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 12px;
  background: rgba(16, 185, 129, 0.1);
  color: var(--success);
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 8px;
  animation: bounceIn 0.6s var(--transition-timing);
}

@keyframes bounceIn {
  0% { transform: scale(0); opacity: 0; }
  50% { transform: scale(1.1); }
  100% { transform: scale(1); opacity: 1; }
}

/* Chart */
.chart-container {
  margin: 20px 0;
  text-align: center;
}

/* Schedule */
.schedule-toggle {
  margin-top: 20px;
}

.schedule-toggle summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 10px;
  background: var(--bg-input);
  border-radius: 8px;
  list-style: none;
}

.schedule-toggle summary::-webkit-details-marker { display: none; }
.schedule-toggle summary::before { content: '📋 '; }

.table-wrapper {
  max-height: 400px;
  overflow-y: auto;
  margin-top: 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
}

thead { position: sticky; top: 0; z-index: 1; }

th {
  background: var(--primary);
  color: white;
  padding: 8px 10px;
  text-align: right;
  font-weight: 600;
  white-space: nowrap;
}

td {
  padding: 6px 10px;
  border-bottom: 1px solid var(--border);
  text-align: right;
}

tr:nth-child(even) { background: var(--bg-input); }

/* Ad Slots */
.ad-slot { text-align: center; padding: 12px 0; min-height: 90px; }

/* Features */
.features { padding: 40px 0; background: linear-gradient(135deg, #EFF6FF, #F8FAFC); }

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}

.feature-card {
  background: white;
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
  border: 1px solid var(--border);
}

.feature-icon { font-size: 1.8rem; margin-bottom: 8px; }
.feature-card h3 { font-size: 0.95rem; font-weight: 600; margin-bottom: 4px; }
.feature-card p { font-size: 0.82rem; color: var(--text-dim); }

/* FAQ */
.faq { padding: 40px 0; }

.section-title { text-align: center; font-size: 1.4rem; font-weight: 700; margin-bottom: 24px; }

.faq-list { max-width: 650px; margin: 0 auto; }

.faq-item {
  margin-bottom: 8px;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow: hidden;
}

.faq-q {
  width: 100%;
  padding: 14px 18px;
  background: transparent;
  border: none;
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-q::after { content: '+'; font-size: 1.2rem; color: var(--primary); transition: transform 0.2s; }
.faq-q.open::after { transform: rotate(45deg); }

.faq-a { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.faq-a p { padding: 0 18px 14px; font-size: 0.88rem; color: var(--text-dim); }

/* Footer */
.footer {
  padding: 24px 0;
  text-align: center;
  border-top: 1px solid rgba(255,255,255,0.1);
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
}

.footer-text {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.8);
  margin-bottom: 4px;
}

.footer-disclaimer {
  font-size: 0.72rem;
  color: rgba(255,255,255,0.6);
  opacity: 0.9;
}

.footer a:hover {
  color: #fff !important;
}

/* Responsive */
@media (max-width: 768px) {
  .calc-layout { grid-template-columns: 1fr; }
  .nav { display: none; }
  .nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    padding: 16px;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
  }
  .nav-toggle { display: block; }
  .hero-title { font-size: 1.5rem; }
  .tools-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .result-value { font-size: 1.5rem; }
  .form-actions { flex-direction: column; }
}

/* Fade-in on scroll animation */
.fade-in-section {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s var(--transition-timing), transform 0.6s var(--transition-timing);
}

.fade-in-section.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Loading spinner */
.loading-spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.btn-primary.loading {
  pointer-events: none;
  opacity: 0.7;
}

.btn-primary.loading::before {
  content: '';
  display: inline-block;
  width: 16px;
  height: 16px;
  margin-right: 8px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

/* Success checkmark animation */
@keyframes checkmark {
  0% {
    transform: scale(0) rotate(45deg);
    opacity: 0;
  }
  50% {
    transform: scale(1.2) rotate(45deg);
  }
  100% {
    transform: scale(1) rotate(45deg);
    opacity: 1;
  }
}

.success-check {
  display: inline-block;
  width: 16px;
  height: 16px;
  border-right: 3px solid var(--success);
  border-bottom: 3px solid var(--success);
  transform: rotate(45deg);
  animation: checkmark 0.4s var(--transition-timing);
}

/* Focus visible for accessibility */
*:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* Skip to main content link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--primary);
  color: white;
  padding: 8px 16px;
  text-decoration: none;
  border-radius: 0 0 8px 0;
  z-index: 1000;
  transition: top var(--transition-speed) var(--transition-timing);
}

.skip-link:focus {
  top: 0;
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --bg-card: #1e293b;
    --bg-input: #1e293b;
    --text: #f1f5f9;
    --text-dim: #94a3b8;
    --border: #334155;
    --shadow: 0 1px 3px rgba(0,0,0,0.3);
  }

  /* Header & Breadcrumb */
  .header {
    background: #1e293b;
    border-color: #334155;
  }

  .breadcrumb {
    background: #1e293b;
    border-color: #334155;
  }

  /* Hero */
  .hero {
    background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  }

  /* Cards & forms */
  .tool-card,
  .calc-form,
  .calc-results,
  .faq-item,
  .feature-card {
    background: var(--bg-card);
    border-color: var(--border);
    color: var(--text);
  }

  .trust-badge {
    background: #1e293b;
    border-color: #334155;
    color: var(--text);
  }

  /* Inputs */
  .form-group input,
  .form-group select,
  .email-form input[type="email"] {
    background: #334155;
    border-color: #475569;
    color: var(--text);
  }

  .form-group input::placeholder,
  .email-form input[type="email"]::placeholder {
    color: #64748b;
  }

  .form-group input:focus,
  .form-group select:focus,
  .email-form input[type="email"]:focus {
    background: #334155;
  }

  /* Result stats */
  .result-stat {
    background: #334155;
  }

  .result-stat:hover {
    background: #475569;
  }

  .result-big {
    background: linear-gradient(135deg, #1e3a8a, #1e40af);
  }

  /* Nav open state */
  .nav.open {
    background: #1e293b;
    border-color: #334155;
  }

  /* Action buttons */
  .action-btn {
    background: #334155;
    border-color: #475569;
    color: var(--text);
  }

  .action-btn:hover {
    background: #475569;
    border-color: var(--primary);
    color: var(--text);
  }

  /* Share buttons */
  .share-menu {
    background: #334155;
  }

  .share-btn {
    background: #1e293b;
    border-color: #475569;
    color: var(--text);
  }

  .share-btn:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
  }

  /* Secondary button */
  .btn-secondary {
    background: #334155;
    border-color: #475569;
    color: var(--text-dim);
  }

  .btn-secondary:hover {
    background: #475569;
    border-color: #64748b;
  }

  /* Schedule toggle */
  .schedule-toggle summary {
    background: #334155;
    color: var(--text);
  }

  /* Details/Summary */
  details[open] summary {
    background: #1e3a8a;
    color: #93c5fd;
  }

  details summary:hover {
    background: #334155;
  }

  /* SEO content sections */
  .how-it-works,
  .use-cases,
  .quick-tips,
  .calculator-faq,
  .example-calculation {
    background: #1e293b;
    color: var(--text);
  }

  .how-it-works h2,
  .use-cases h2,
  .quick-tips h2,
  .calculator-faq h2,
  .example-calculation h2 {
    color: var(--text);
    border-color: #334155;
  }

  .how-it-works h3 {
    color: var(--text);
  }

  .use-case-card {
    background: #334155;
    color: var(--text);
  }

  .use-case-card h3 {
    color: var(--text);
  }

  .tip-compact {
    background: #1e3a8a33;
  }

  .tip-compact p {
    color: var(--text);
  }

  .example-box {
    background: #064e3b33;
    border-color: #10b981;
  }

  .example-note {
    color: #6ee7b7;
    border-color: #065f46;
  }

  .faq-item {
    background: #334155;
  }

  .faq-item summary {
    color: var(--text);
  }

  .faq-item p {
    color: var(--text-dim);
  }

  /* Email capture card */
  .email-capture-card {
    background: linear-gradient(135deg, #1e3a8a33, #1e40af33);
    border-color: #3b82f6;
  }

  .email-capture-card h3 {
    color: #93c5fd;
  }

  /* Table */
  td {
    color: var(--text);
  }

  tr:nth-child(even) {
    background: #334155;
  }

  tbody tr:hover {
    background: #1e3a8a !important;
  }

  /* Skeleton loading */
  .skeleton {
    background: linear-gradient(90deg, #334155 25%, #475569 50%, #334155 75%);
    background-size: 200% 100%;
  }
}

/* Mobile thumb-friendly buttons */
@media (max-width: 768px) {
  .btn-primary,
  .btn-secondary {
    min-height: 44px;
    padding: 12px 16px;
  }

  /* Bottom sheet for results on mobile */
  .calc-results {
    position: relative;
  }

  /* Swipe indicator */
  .table-wrapper::before {
    content: '👈 Swipe to see more';
    display: block;
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-dim);
    padding: 4px;
    background: var(--bg-input);
    border-radius: 4px 4px 0 0;
  }

  .table-wrapper {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  .btn-primary {
    border: 2px solid currentColor;
  }

  .form-group input:focus,
  .form-group select:focus {
    border-width: 3px;
  }
}

/* Range slider styles */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  outline: none;
  transition: background var(--transition-speed);
}

input[type="range"]:hover {
  background: var(--primary-light);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--primary);
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition-speed) var(--transition-timing);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 4px 8px rgba(37, 99, 235, 0.3);
}

input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--primary);
  border-radius: 50%;
  cursor: pointer;
  border: none;
  transition: all var(--transition-speed) var(--transition-timing);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

input[type="range"]::-moz-range-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 4px 8px rgba(37, 99, 235, 0.3);
}

/* Numeric input stepper styling */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  opacity: 0.6;
  transition: opacity var(--transition-speed);
}

input[type="number"]:hover::-webkit-inner-spin-button,
input[type="number"]:hover::-webkit-outer-spin-button {
  opacity: 1;
}

/* Tooltip icon */
.tooltip-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  margin-left: 4px;
  background: var(--primary-light);
  color: var(--primary-dark);
  border-radius: 50%;
  font-size: 0.7rem;
  font-weight: 700;
  cursor: help;
  transition: all var(--transition-speed) var(--transition-timing);
}

.tooltip-icon:hover {
  background: var(--primary);
  color: white;
  transform: scale(1.2);
}

/* Result actions */
.result-actions {
  display: flex;
  gap: 8px;
  margin: 16px 0;
  flex-wrap: wrap;
}

.action-btn {
  flex: 1;
  min-width: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 16px;
  background: var(--bg-input);
  border: 2px solid var(--border);
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  color: var(--text);
  transition: all var(--transition-speed) var(--transition-timing);
}

.action-btn:hover {
  background: white;
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(37, 99, 235, 0.15);
}

.action-icon {
  font-size: 1.1rem;
  transition: transform var(--transition-speed) var(--transition-timing);
}

.action-btn:hover .action-icon {
  transform: scale(1.2);
}

.action-text {
  font-size: 0.85rem;
}

/* Share menu */
.share-menu {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 8px;
  margin: 16px 0;
  padding: 16px;
  background: var(--bg-input);
  border-radius: 8px;
  animation: slideDown 0.3s var(--transition-timing);
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.share-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  background: white;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  color: var(--text);
  transition: all var(--transition-speed) var(--transition-timing);
}

.share-btn:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  transform: translateY(-2px);
}

/* Email capture card */
.email-capture-card {
  background: linear-gradient(135deg, #EFF6FF, #DBEAFE);
  border: 2px solid var(--primary-light);
  border-radius: var(--radius);
  padding: 20px;
  margin: 20px 0;
  text-align: center;
}

.email-capture-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--primary-dark);
}

.email-capture-card p {
  font-size: 0.9rem;
  color: var(--text-dim);
  margin-bottom: 12px;
}

.email-form {
  display: flex;
  gap: 8px;
  max-width: 400px;
  margin: 0 auto 12px;
}

.email-form input[type="email"] {
  flex: 1;
  padding: 10px 14px;
  border: 2px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  background: white;
  transition: all var(--transition-speed) var(--transition-timing);
}

.email-form input[type="email"]:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.email-form button {
  padding: 10px 20px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: all var(--transition-speed) var(--transition-timing);
}

.email-form button:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.privacy-note {
  font-size: 0.75rem;
  color: var(--text-dim);
  margin: 0;
}

/* Slider improvements */
.slider {
  margin-top: 8px;
}

/* Mobile optimizations */
@media (max-width: 768px) {
  .action-btn {
    min-width: 100%;
  }

  .action-text {
    display: none;
  }

  .action-btn {
    justify-content: center;
    padding: 12px;
  }

  .share-menu {
    grid-template-columns: 1fr 1fr;
  }

  .email-form {
    flex-direction: column;
  }
}

/* Additional animations */
@keyframes fadeOut {
  from {
    opacity: 1;
    transform: scale(1);
  }
  to {
    opacity: 0;
    transform: scale(0.95);
  }
}

/* Hero animations */
.hero-title {
  animation: slideInDown 0.6s var(--transition-timing);
}

@keyframes slideInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-subtitle {
  animation: fadeIn 0.8s var(--transition-timing) 0.2s backwards;
}

.trust-signals {
  animation: fadeIn 1s var(--transition-timing) 0.4s backwards;
}

.trust-badge {
  transition: all var(--transition-speed) var(--transition-timing);
}

.trust-badge:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* Usage counter pulse */
#usageCount {
  animation: pulse 2s ease-in-out infinite;
}

/* Details summary enhancement */
details summary {
  transition: all var(--transition-speed) var(--transition-timing);
}

details[open] summary {
  background: var(--primary-light);
  color: var(--primary-dark);
}

details summary:hover {
  background: var(--border);
}

/* Table enhancements */
tbody tr {
  transition: background var(--transition-speed) var(--transition-timing);
}

tbody tr:hover {
  background: var(--primary-light) !important;
}

/* Chart container animation */
.chart-container {
  animation: fadeIn 0.5s var(--transition-timing) 0.8s backwards;
}

/* Print styles */
@media print {
  .header,
  .footer,
  .nav,
  .ad-slot,
  .form-actions,
  .result-actions,
  .share-menu,
  .email-capture-card {
    display: none !important;
  }

  .calc-results {
    box-shadow: none !important;
    border: 1px solid #ccc !important;
  }

  body {
    background: white !important;
  }
}

/* Performance: will-change for animated elements */
.tool-card:hover,
.btn-primary:hover,
.result-value {
  will-change: transform;
}

/* Prevent layout shift */
img,
canvas {
  max-width: 100%;
  height: auto;
}

/* Stagger animations for tool cards */
.tool-card:nth-child(1) { animation: fadeIn 0.5s var(--transition-timing) 0.1s backwards; }
.tool-card:nth-child(2) { animation: fadeIn 0.5s var(--transition-timing) 0.2s backwards; }
.tool-card:nth-child(3) { animation: fadeIn 0.5s var(--transition-timing) 0.3s backwards; }
.tool-card:nth-child(4) { animation: fadeIn 0.5s var(--transition-timing) 0.4s backwards; }
.tool-card:nth-child(5) { animation: fadeIn 0.5s var(--transition-timing) 0.5s backwards; }
.tool-card:nth-child(6) { animation: fadeIn 0.5s var(--transition-timing) 0.6s backwards; }

/* Input number spinner custom styling */
input[type="number"] {
  -moz-appearance: textfield;
}

/* Progress indicator for loading */
@keyframes progress {
  0% { width: 0%; }
  100% { width: 100%; }
}

.loading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--primary);
  animation: progress 2s ease-in-out;
  z-index: 9999;
}

/* Smooth color transitions */
* {
  transition-property: background-color, border-color, color, fill, stroke;
}

/* Only animate on user interaction, not on page load for better performance */
@media (hover: hover) and (pointer: fine) {
  .tool-card,
  .btn-primary,
  .btn-secondary,
  .action-btn,
  .nav a {
    will-change: auto;
  }
}

/* Accessibility: Focus indicators */
button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
}

/* Confetti animation (optional, subtle) */
@keyframes confetti {
  0% {
    transform: translateY(0) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translateY(100vh) rotate(720deg);
    opacity: 0;
  }
}

.confetti {
  position: fixed;
  width: 10px;
  height: 10px;
  background: var(--primary);
  animation: confetti 3s ease-out forwards;
  pointer-events: none;
  z-index: 9999;
}

/* On-Page SEO Content Sections */
.how-it-works,
.use-cases,
.quick-tips,
.calculator-faq,
.example-calculation {
  margin: 3rem 0;
  padding: 2rem;
  background: white;
  border-radius: 12px;
}

.how-it-works h2,
.use-cases h2,
.quick-tips h2,
.calculator-faq h2,
.example-calculation h2 {
  color: var(--text);
  font-size: 1.75rem;
  margin-bottom: 1.5rem;
  border-bottom: 2px solid #e2e8f0;
  padding-bottom: 1rem;
}

.how-it-works h3 {
  color: var(--text);
  font-size: 1.25rem;
  margin-top: 2rem;
  margin-bottom: 1rem;
}

.how-it-works ul,
.how-it-works ol {
  margin-left: 1.5rem;
  line-height: 1.8;
}

.how-it-works li {
  margin-bottom: 0.75rem;
}

.use-case-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.use-case-card {
  padding: 1.5rem;
  background: #f8fafc;
  border-radius: 8px;
  border-left: 4px solid var(--primary);
}

.use-case-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.tips-compact {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.tip-compact {
  display: flex;
  gap: 1rem;
  padding: 1rem;
  background: #eff6ff;
  border-radius: 8px;
  align-items: flex-start;
}

.tip-compact .tip-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.tip-compact p {
  margin: 0;
  line-height: 1.6;
}

.example-box {
  background: #f0fdf4;
  border: 2px solid #10b981;
  border-radius: 8px;
  padding: 1.5rem;
  margin-top: 1rem;
}

.example-box ul {
  margin: 1rem 0;
}

.example-note {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid #86efac;
  font-style: italic;
  color: #065f46;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.faq-item {
  background: #f8fafc;
  border-radius: 8px;
  padding: 1rem;
  cursor: pointer;
}

.faq-item summary {
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--primary);
  flex-shrink: 0;
}

.faq-item[open] summary::after {
  content: '−';
}

.faq-item p {
  margin-top: 1rem;
  line-height: 1.7;
  color: #64748b;
}

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

  .how-it-works,
  .use-cases,
  .quick-tips,
  .calculator-faq,
  .example-calculation {
    padding: 1.5rem;
    margin: 2rem 0;
  }
}

/* Enhanced Hero CTA Buttons */
.btn-hero-primary:hover {
  background: var(--primary-dark) !important;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.4) !important;
}

.btn-hero-primary:active {
  transform: translateY(0);
}

.btn-hero-secondary:hover {
  background: var(--primary) !important;
  color: white !important;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.btn-hero-secondary:active {
  transform: translateY(0);
}

/* Enhanced Tool Cards */
.tool-card {
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), #10b981);
  transform: scaleX(0);
  transition: transform 0.3s;
}

.tool-card:hover::before {
  transform: scaleX(1);
}

.tool-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.15);
}

/* Responsive Hero Buttons */
@media (max-width: 768px) {
  .btn-hero-primary,
  .btn-hero-secondary {
    width: 100%;
    text-align: center;
  }

  /* Mobile Hero adjustments */
  .hero-title {
    font-size: 2rem !important;
    line-height: 1.3 !important;
  }

  .hero-subtitle {
    font-size: 1.1rem !important;
  }

  /* Mobile Stats Section */
  .stats-section {
    padding: 2rem 0 !important;
  }

  .stats-section > div > div {
    gap: 1.5rem !important;
  }

  .stats-section div[style*="font-size: 3rem"] {
    font-size: 2rem !important;
  }

  .stats-section div[style*="font-size: 1.1rem"] {
    font-size: 0.95rem !important;
  }

  /* Mobile Testimonials */
  section > div > div[style*="grid-template-columns"] {
    grid-template-columns: 1fr !important;
  }
}