/* CalcPro - Complete Professional CSS with Orange Theme */
:root {
  --primary-color: #f97316;
  --primary-dark: #ea580c;
  --primary-light: #fdba74;
  --secondary-color: #64748b;
  --accent-color: #ef4444;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --background-primary: #ffffff;
  --background-secondary: #f8fafc;
  --background-tertiary: #f1f5f9;
  --border-color: #e2e8f0;
  --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-heavy: 0 8px 32px rgba(0, 0, 0, 0.16);
  --border-radius: 16px;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --gradient: linear-gradient(135deg, #f97316 0%, #ea580c 100%);
  --gradient-light: linear-gradient(135deg, #fed7aa 0%, #fdba74 100%);
  --card-gradient: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
}

.dark-theme {
  --text-primary: #f9fafb;
  --text-secondary: #d1d5db;
  --background-primary: #111827;
  --background-secondary: #1f2937;
  --background-tertiary: #172032;
  --border-color: #374151;
  --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-heavy: 0 8px 32px rgba(0, 0, 0, 0.5);
  --card-gradient: linear-gradient(135deg, #1f2937 0%, #172032 100%);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--background-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  transition: var(--transition);
  min-height: 100vh;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== NAVIGATION ===== */
.navbar {
  background: var(--background-primary);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-light);
  border-bottom: 1px solid var(--border-color);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-primary);
  font-size: 1.5rem;
  font-weight: 800;
  text-decoration: none;
}

.nav-brand span, .nav-brand .site-title span {
  color: var(--primary-color);
}

.badge {
  background: var(--gradient);
  color: white;
  font-size: 0.7rem;
  padding: 0.2rem 0.75rem;
  border-radius: 20px;
  margin-left: 0.5rem;
  font-weight: 600;
}

.nav-brand i {
  font-size: 1.8rem;
  color: var(--primary-color);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 0.5rem;
  align-items: center;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  padding: 0.75rem 1.5rem;
  border-radius: 50px;
  font-weight: 600;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.95rem;
}

.nav-link:hover,
.nav-link.active {
  background: var(--gradient);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(249, 115, 22, 0.3);
}

.cta-button {
  background: var(--gradient);
  color: white;
  border: 2px solid transparent;
  font-weight: 700;
}

.cta-button:hover {
  background: var(--primary-dark);
  transform: translateY(-2px) scale(1.05);
  box-shadow: 0 6px 25px rgba(249, 115, 22, 0.4);
}

.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 4px;
  z-index: 1001;
}

.hamburger span {
  width: 25px;
  height: 3px;
  background: var(--text-primary);
  transition: var(--transition);
  border-radius: 2px;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
  background: var(--text-primary);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -6px);
  background: var(--text-primary);
}

/* ===== HOME PAGE HERO ===== */
.hero-section {
  background: linear-gradient(135deg, var(--background-secondary) 0%, var(--background-primary) 100%);
  color: var(--text-primary);
  padding: 6rem 1.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 1px solid var(--border-color);
}

.hero-pattern {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(circle at 20% 80%, rgba(249, 115, 22, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(249, 115, 22, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 40% 40%, rgba(249, 115, 22, 0.03) 0%, transparent 50%);
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 900px;
  width: 100%;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--gradient);
  color: white;
  padding: 0.75rem 2rem;
  border-radius: 50px;
  font-weight: 600;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-medium);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 900;
  margin-bottom: 1.5rem;
  line-height: 1.1;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.3rem;
  margin-bottom: 3rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.6;
}

.hero-highlights {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 4rem;
  flex-wrap: wrap;
}

.highlight-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 1.5rem;
  background: var(--card-gradient);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  min-width: 180px;
  transition: var(--transition);
  box-shadow: var(--shadow-light);
}

.highlight-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-medium);
  border-color: var(--primary-color);
}

.highlight-icon {
  width: 60px;
  height: 60px;
  background: var(--gradient);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  color: white;
  font-size: 1.5rem;
}

.highlight-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary-color);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.highlight-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.hero-cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.cta-text {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

/* ===== CALCULATOR CARDS SECTION ===== */
.calculators-section {
  padding: 6rem 1.5rem;
  background: var(--background-primary);
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-header h2 {
  font-size: 2.8rem;
  margin-bottom: 1rem;
  font-weight: 800;
  color: var(--text-primary);
  position: relative;
  display: inline-block;
}

.section-header h2::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: var(--gradient);
  border-radius: 2px;
}

.section-header p {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 2rem auto 0;
  line-height: 1.6;
}

.calculator-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2.5rem;
  margin-top: 3rem;
}

.calculator-card {
  background: var(--card-gradient);
  border-radius: var(--border-radius);
  padding: 2.5rem;
  border: 1px solid var(--border-color);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-light);
}

.calculator-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 5px;
  background: var(--gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

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

.calculator-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-heavy);
  border-color: var(--primary-light);
}

.card-header {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.card-icon-wrapper {
  width: 80px;
  height: 80px;
  background: var(--gradient);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 2rem;
  flex-shrink: 0;
  box-shadow: var(--shadow-medium);
}

.card-title {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.card-badge {
  background: var(--gradient);
  color: white;
  padding: 0.3rem 1rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  display: inline-block;
}

.card-description {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.7;
}

.card-features {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}

.feature-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-secondary);
}

.feature-icon {
  color: var(--success-color);
  font-size: 1rem;
}

.card-action {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.card-link {
  background: var(--gradient);
  color: white;
  padding: 1rem 2rem;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  transition: var(--transition);
  border: none;
  cursor: pointer;
  width: 100%;
  justify-content: center;
  box-shadow: var(--shadow-medium);
}

.card-link:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-heavy);
}

/* ===== MAIN CTA SECTIONS ===== */
.main-cta {
  padding: 4rem 1.5rem;
  background: var(--gradient);
  color: white;
  text-align: center;
}

.cta-content {
  max-width: 800px;
  margin: 0 auto;
}

.cta-content h2 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  font-weight: 800;
}

.cta-content p {
  font-size: 1.2rem;
  opacity: 0.9;
  margin-bottom: 3rem;
  line-height: 1.6;
}

.cta-buttons {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  flex-wrap: wrap;
}

.primary-btn, .secondary-btn {
  padding: 1.2rem 3rem;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  transition: var(--transition);
  border: none;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  font-size: 1rem;
}

.primary-btn {
  background: var(--gradient);
  color: white;
  box-shadow: var(--shadow-medium);
}

.primary-btn:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-heavy);
}

.secondary-btn {
  background: var(--background-primary);
  color: var(--text-primary);
  border: 2px solid var(--primary-color);
}

.secondary-btn:hover {
  background: var(--gradient);
  color: white;
  transform: translateY(-3px);
  box-shadow: var(--shadow-medium);
}

.cta-button {
  padding: 1.2rem 3rem;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  transition: var(--transition);
  border: 2px solid transparent;
}

.cta-button.primary {
  background: white;
  color: var(--primary-dark);
  box-shadow: var(--shadow-medium);
}

.cta-button.primary:hover {
  background: #f8fafc;
  transform: translateY(-3px);
  box-shadow: var(--shadow-heavy);
}

.cta-button.secondary {
  background: transparent;
  color: white;
  border-color: rgba(255, 255, 255, 0.3);
}

.cta-button.secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-3px);
  box-shadow: var(--shadow-heavy);
}

/* ===== FEATURES PAGE ===== */
.features-hero {
  background: var(--gradient);
  color: white;
  padding: 6rem 1.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.features-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 10% 20%, rgba(255,255,255,0.1) 0%, transparent 50%),
    radial-gradient(circle at 90% 80%, rgba(255,255,255,0.1) 0%, transparent 50%);
}

.features-hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
  margin: 0 auto;
}

.features-hero h1 {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
  font-weight: 900;
  line-height: 1.1;
}

.features-hero p {
  font-size: 1.3rem;
  opacity: 0.9;
  margin-bottom: 3rem;
  line-height: 1.6;
}

.features-categories {
  padding: 4rem 1.5rem;
  background: var(--background-primary);
}

.category-filter {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 4rem;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 1rem 2.5rem;
  border: 2px solid var(--primary-color);
  background: transparent;
  color: var(--primary-color);
  border-radius: 50px;
  cursor: pointer;
  transition: var(--transition);
  font-weight: 600;
  font-size: 1rem;
  box-shadow: var(--shadow-light);
}

.filter-btn.active,
.filter-btn:hover {
  background: var(--primary-color);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-medium);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2.5rem;
}

.feature-card {
  background: var(--card-gradient);
  border-radius: var(--border-radius);
  padding: 2.5rem;
  border: 1px solid var(--border-color);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-light);
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 5px;
  background: var(--gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

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

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-heavy);
  border-color: var(--primary-light);
}

.feature-card-icon {
  width: 80px;
  height: 80px;
  background: var(--gradient);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 2rem;
  color: white;
  font-size: 2rem;
  box-shadow: var(--shadow-medium);
}

.feature-card h3 {
  font-size: 1.4rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
  font-weight: 700;
}

.feature-card p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

.feature-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.feature-list li {
  padding: 0.5rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1.5rem;
}

.feature-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: bold;
}

/* ===== COMPARISON TABLE ===== */
.comparison-section {
  padding: 4rem 1.5rem;
  background: var(--background-secondary);
}

.comparison-table-wrapper {
  background: var(--card-gradient);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  overflow: hidden;
  box-shadow: var(--shadow-medium);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
}

.comparison-table thead {
  background: var(--gradient);
}

.comparison-table th {
  padding: 1.5rem;
  color: white;
  font-weight: 600;
  text-align: center;
  border-right: 1px solid rgba(255, 255, 255, 0.1);
}

.comparison-table th:last-child {
  border-right: none;
}

.comparison-table tbody tr {
  border-bottom: 1px solid var(--border-color);
}

.comparison-table tbody tr:last-child {
  border-bottom: none;
}

.comparison-table tbody tr:nth-child(even) {
  background: rgba(0, 0, 0, 0.02);
}

.dark-theme .comparison-table tbody tr:nth-child(even) {
  background: rgba(255, 255, 255, 0.02);
}

.comparison-table td {
  padding: 1.5rem;
  text-align: center;
  color: var(--text-secondary);
  border-right: 1px solid var(--border-color);
}

.comparison-table td:last-child {
  border-right: none;
}

.comparison-table .feature-name {
  font-weight: 600;
  color: var(--text-primary);
  text-align: left;
}

.comparison-table .check {
  color: var(--success-color);
  font-size: 1.2rem;
}

.comparison-table .cross {
  color: var(--error-color);
  font-size: 1.2rem;
}

/* ===== HOW-TO PAGE ===== */
.howto-hero {
  background: var(--gradient);
  color: white;
  padding: 6rem 1.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.howto-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 20% 30%, rgba(255,255,255,0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(255,255,255,0.1) 0%, transparent 50%);
}

.howto-hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
  margin: 0 auto;
}

.howto-hero h1 {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
  font-weight: 900;
  line-height: 1.1;
}

.howto-hero p {
  font-size: 1.3rem;
  opacity: 0.9;
  margin-bottom: 3rem;
  line-height: 1.6;
}

/* ===== STEPS SECTION ===== */
.steps-section {
  padding: 4rem 1.5rem;
  background: var(--background-primary);
}

.steps-container {
  max-width: 1000px;
  margin: 0 auto;
}

.step-card {
  display: flex;
  gap: 3rem;
  margin-bottom: 4rem;
  padding: 3rem;
  background: var(--card-gradient);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-light);
}

.step-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 5px;
  height: 100%;
  background: var(--gradient);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.3s ease;
}

.step-card:hover::before {
  transform: scaleY(1);
}

.step-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-heavy);
  border-color: var(--primary-light);
}

.step-number {
  width: 80px;
  height: 80px;
  background: var(--gradient);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 2rem;
  font-weight: 800;
  flex-shrink: 0;
  box-shadow: var(--shadow-medium);
}

.step-content {
  flex: 1;
}

.step-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.step-icon {
  width: 50px;
  height: 50px;
  background: var(--primary-light);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.5rem;
}

.step-title {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-primary);
}

.step-description {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

.step-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.step-list li {
  padding: 0.5rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1.5rem;
}

.step-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--primary-color);
  font-weight: bold;
}

.step-visual {
  flex-shrink: 0;
  width: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.step-image {
  width: 150px;
  height: 150px;
  background: var(--gradient);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 3rem;
  box-shadow: var(--shadow-heavy);
}

/* ===== TIPS SECTION ===== */
.tips-section {
  padding: 4rem 1.5rem;
  background: var(--background-secondary);
}

.tips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2.5rem;
  max-width: 1000px;
  margin: 0 auto;
}

.tip-card {
  background: var(--card-gradient);
  border-radius: var(--border-radius);
  padding: 2.5rem;
  border: 1px solid var(--border-color);
  transition: var(--transition);
  text-align: center;
  box-shadow: var(--shadow-light);
}

.tip-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-heavy);
  border-color: var(--primary-light);
}

.tip-icon-wrapper {
  width: 80px;
  height: 80px;
  background: var(--gradient);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 2rem;
  color: white;
  font-size: 2rem;
  box-shadow: var(--shadow-medium);
}

.tip-card h3 {
  font-size: 1.4rem;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
  font-weight: 700;
}

.tip-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.tip-list li {
  padding: 0.75rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1.5rem;
  text-align: left;
}

.tip-list li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--primary-color);
  font-size: 1.5rem;
  line-height: 1;
}

/* ===== FAQ SECTION ===== */
.faq-section {
  padding: 4rem 1.5rem;
  background: var(--background-primary);
}

.faq-container {
  max-width: 1000px;
  margin: 0 auto;
}

.faq-grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.faq-item {
  background: var(--card-gradient);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  overflow: hidden;
  transition: var(--transition);
  box-shadow: var(--shadow-light);
}

.faq-item:hover {
  border-color: var(--primary-light);
  box-shadow: var(--shadow-medium);
}

.faq-question {
  padding: 2rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--background-primary);
}

.faq-question h3 {
  font-size: 1.2rem;
  color: var(--text-primary);
  font-weight: 600;
  margin: 0;
}

.faq-toggle {
  color: var(--primary-color);
  font-size: 1.5rem;
  transition: transform 0.3s ease;
}

.faq-item.active .faq-toggle {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 2rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
  padding: 0 2rem 2rem;
  max-height: 500px;
}

.faq-answer p {
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== CALCULATOR PAGES ===== */
.calculator-page {
  padding: 3rem 1.5rem;
  min-height: 80vh;
  display: flex;
  align-items: center;
  background: var(--background-secondary);
}

.calc-container {
  max-width: 600px;
  margin: 0 auto;
  background: var(--card-gradient);
  border-radius: var(--border-radius);
  padding: 2.5rem;
  box-shadow: var(--shadow-medium);
  border: 1px solid var(--border-color);
  width: 100%;
}

.calc-header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.calc-header h2 {
  font-size: 2.2rem;
  margin-bottom: 0.5rem;
  font-weight: 800;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.calc-header p {
  color: var(--text-secondary);
}

/* ===== CALCULATOR DISPLAY ===== */
.calc-display-container {
  background: var(--background-primary);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  border: 2px solid var(--border-color);
  min-height: 120px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.05);
}

.calc-expression {
  font-size: 1rem;
  color: var(--text-secondary);
  text-align: right;
  min-height: 1.5rem;
  font-family: 'Inter', monospace;
  font-weight: 500;
  margin-bottom: 0.5rem;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.calc-display {
  width: 100%;
  padding: 0;
  font-size: 2.5rem;
  text-align: right;
  border: none;
  background: transparent;
  color: var(--text-primary);
  font-family: 'Inter', monospace;
  font-weight: 700;
  outline: none;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

/* ===== CALCULATOR BUTTONS ===== */
.calc-keys {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.calc-btn {
  padding: 1.25rem;
  font-size: 1.3rem;
  border: none;
  border-radius: 12px;
  background: var(--background-primary);
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
  font-weight: 600;
  border: 2px solid var(--border-color);
  font-family: 'Inter', sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 65px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.calc-btn:hover {
  background: var(--background-secondary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-light);
  border-color: var(--primary-light);
}

.calc-btn:active {
  transform: translateY(0);
  box-shadow: none;
}

.calc-btn.operator {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
  font-size: 1.5rem;
}

.calc-btn.operator:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
}

.calc-btn.equals {
  background: var(--success-color);
  color: white;
  border-color: var(--success-color);
  font-size: 1.8rem;
}

.calc-btn.equals:hover {
  background: #059669;
  transform: translateY(-2px);
}

.calc-btn.clear, .calc-btn.function {
  background: var(--error-color);
  color: white;
  border-color: var(--error-color);
  font-weight: 600;
}

.calc-btn.clear:hover, .calc-btn.function:hover {
  background: #dc2626;
}

.calc-btn.sci-btn {
  background: var(--warning-color);
  color: white;
  border-color: var(--warning-color);
  font-size: 1rem;
}

.calc-btn.sci-btn:hover {
  background: #d97706;
}

.calc-btn i {
  font-size: 1.2rem;
}

/* Scientific Calculator Layout */
.sci-keys {
  grid-template-columns: repeat(5, 1fr);
}

/* ===== CALCULATOR FEATURES ===== */
.calculator-features {
  margin-top: 2rem;
  padding: 1.5rem;
  background: var(--background-primary);
  border-radius: 12px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-light);
}

.calculator-features h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.features-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.75rem;
}

.features-list span {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.features-list span i {
  color: var(--success-color);
  font-size: 0.9rem;
}

/* ===== FORM CALCULATORS ===== */
.form-calculator {
  max-width: 500px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.form-input {
  width: 100%;
  padding: 1rem;
  border: 2px solid var(--border-color);
  border-radius: 10px;
  font-size: 1rem;
  background: var(--background-primary);
  color: var(--text-primary);
  transition: var(--transition);
  font-family: 'Inter', sans-serif;
}

.form-input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.1);
}

.calculate-btn {
  width: 100%;
  padding: 1rem;
  background: var(--gradient);
  color: white;
  border: none;
  border-radius: 10px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 1rem;
  box-shadow: var(--shadow-medium);
}

.calculate-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-heavy);
}

.result-box {
  margin-top: 2rem;
  padding: 1.5rem;
  background: var(--background-primary);
  border-radius: 12px;
  border: 1px solid var(--border-color);
  display: none;
  box-shadow: var(--shadow-light);
}

.result-box h3 {
  margin-bottom: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* ===== AGE CALCULATOR SPECIFIC ===== */
.time-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.age-result {
  display: flex;
  justify-content: space-around;
  margin: 1.5rem 0;
  text-align: center;
}

.age-unit {
  flex: 1;
}

.age-value {
  font-size: 2.5rem;
  font-weight: 800;
  display: block;
  color: var(--primary-color);
  line-height: 1;
}

.age-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
}

.additional-info {
  margin-top: 1rem;
  padding: 1rem;
  background: var(--background-secondary);
  border-radius: 10px;
  border: 1px solid var(--border-color);
}

/* ===== BMI CALCULATOR SPECIFIC ===== */
.unit-toggle {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.unit-btn {
  flex: 1;
  padding: 1rem;
  border: 2px solid var(--border-color);
  background: var(--background-primary);
  color: var(--text-primary);
  border-radius: 10px;
  cursor: pointer;
  transition: var(--transition);
  font-weight: 600;
}

.unit-btn.active {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.unit-section {
  display: none;
}

.unit-section.active {
  display: block;
}

.bmi-score {
  text-align: center;
  margin: 1.5rem 0;
}

.bmi-value {
  font-size: 3rem;
  font-weight: 800;
  display: block;
  color: var(--text-primary);
}

.bmi-category {
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: 50px;
  display: inline-block;
}

.bmi-scale {
  margin: 2rem 0;
}

.scale-bar {
  width: 100%;
  height: 20px;
  background: var(--background-tertiary);
  border-radius: 10px;
  margin: 1rem 0;
  overflow: hidden;
  position: relative;
  border: 1px solid var(--border-color);
}

.scale-fill {
  height: 100%;
  border-radius: 10px;
  transition: width 0.5s ease;
  background: var(--gradient);
}

.scale-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
}

.bmi-info {
  margin-top: 1.5rem;
  padding: 1rem;
  background: var(--background-secondary);
  border-radius: 12px;
  border: 1px solid var(--border-color);
}

.bmi-categories {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.category-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 1rem;
  background: var(--background-primary);
  border-radius: 10px;
  border: 1px solid var(--border-color);
}

.category-color {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  margin-bottom: 0.5rem;
}

.category-color.underweight { background: var(--primary-color); }
.category-color.normal { background: var(--success-color); }
.category-color.overweight { background: var(--warning-color); }
.category-color.obese { background: var(--error-color); }

.category-range {
  font-weight: 600;
  color: var(--text-primary);
}

.category-name {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* ===== INTEREST CALCULATOR SPECIFIC ===== */
.interest-type {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.interest-btn {
  flex: 1;
  padding: 1rem;
  border: 2px solid var(--border-color);
  background: var(--background-primary);
  color: var(--text-primary);
  border-radius: 10px;
  cursor: pointer;
  transition: var(--transition);
  font-weight: 600;
}

.interest-btn.active {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.compound-options {
  margin-bottom: 1.5rem;
}

.interest-breakdown {
  margin: 1.5rem 0;
  padding: 1.5rem;
  background: var(--background-secondary);
  border-radius: 12px;
  border: 1px solid var(--border-color);
}

.result-item {
  display: flex;
  justify-content: space-between;
  margin: 0.5rem 0;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border-color);
}

.result-label {
  font-weight: 600;
  color: var(--text-primary);
}

.result-value {
  color: var(--primary-color);
  font-weight: 700;
}

.interest-chart {
  margin-top: 1.5rem;
  padding: 1.5rem;
  background: var(--background-primary);
  border-radius: 12px;
  border: 1px solid var(--border-color);
  text-align: center;
}

/* ===== FOOTER ===== */
footer {
  background: var(--background-primary);
  color: var(--text-primary);
  padding: 4rem 1.5rem 2rem;
  margin-top: 4rem;
  border-top: 1px solid var(--border-color);
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 3rem;
  margin-bottom: 2rem;
}

.footer-brand {
  text-align: left;
}

.footer-brand i {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-right: 0.75rem;
}

.footer-brand span {
  font-size: 1.8rem;
  font-weight: 800;
}

.footer-brand p {
  margin-top: 0.5rem;
  color: var(--text-secondary);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.footer-column h4 {
  margin-bottom: 1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.footer-column a {
  display: block;
  color: var(--text-secondary);
  text-decoration: none;
  margin-bottom: 0.5rem;
  transition: var(--transition);
}

.footer-column a:hover {
  color: var(--primary-color);
  transform: translateX(5px);
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.social-links {
  display: flex;
  gap: 1rem;
}

.social-link {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--background-secondary);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  transition: var(--transition);
  border: 1px solid var(--border-color);
}

.social-link:hover {
  background: var(--primary-color);
  color: white;
  transform: translateY(-3px);
  box-shadow: var(--shadow-medium);
}

.footer-info {
  color: var(--text-secondary);
  text-align: center;
}

.contact-info {
  display: flex;
  gap: 2rem;
  margin-top: 0.75rem;
  flex-wrap: wrap;
  justify-content: center;
}

.contact-info a {
  color: var(--text-secondary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition);
}

.contact-info a:hover {
  color: var(--primary-color);
}

/* ===== THEME TOGGLE ===== */
.theme-toggle {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--gradient);
  color: white;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: var(--shadow-heavy);
  z-index: 1000;
  transition: var(--transition);
}

.theme-toggle:hover {
  transform: scale(1.1);
  box-shadow: 0 8px 30px rgba(249, 115, 22, 0.6);
}

/* ===== ERROR NOTIFICATION ===== */
.error-notification {
  position: fixed;
  top: 20px;
  right: 20px;
  background: var(--error-color);
  color: white;
  padding: 1rem 1.5rem;
  border-radius: 10px;
  box-shadow: var(--shadow-heavy);
  z-index: 10000;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  animation: slideIn 0.3s ease;
}

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

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

.animate-in {
  animation: fadeInUp 0.6s ease-out forwards;
}

.calculator-card,
.feature-card,
.tip-card,
.step-card,
.faq-item {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.calculator-card.animate-in,
.feature-card.animate-in,
.tip-card.animate-in,
.step-card.animate-in,
.faq-item.animate-in {
  opacity: 1;
  transform: translateY(0);
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 1024px) {
  .step-card {
    flex-direction: column;
    gap: 2rem;
  }
  
  .step-visual {
    order: -1;
    width: 100%;
  }
  
  .step-image {
    width: 120px;
    height: 120px;
  }
  
  .comparison-table {
    font-size: 0.9rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .footer-links {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    left: -100%;
    top: 70px;
    flex-direction: column;
    background: var(--background-primary);
    width: 100%;
    text-align: center;
    transition: 0.3s;
    box-shadow: var(--shadow-heavy);
    padding: 2rem 0;
    gap: 0;
    z-index: 999;
  }
  
  .nav-menu.active {
    left: 0;
  }
  
  .nav-link {
    width: 100%;
    padding: 1.5rem;
    justify-content: center;
    border-bottom: 1px solid var(--border-color);
  }
  
  .hamburger {
    display: flex;
  }
  
  .hero-title,
  .features-hero h1,
  .howto-hero h1 {
    font-size: 2.5rem;
  }
  
  .section-header h2 {
    font-size: 2.2rem;
  }
  
  .hero-highlights {
    gap: 1rem;
  }
  
  .highlight-item {
    min-width: 150px;
    padding: 1rem;
  }
  
  .hero-subtitle,
  .features-hero p,
  .howto-hero p {
    font-size: 1.1rem;
  }
  
  .calculator-grid,
  .features-grid,
  .tips-grid {
    grid-template-columns: 1fr;
  }
  
  .category-filter {
    flex-direction: column;
    align-items: center;
  }
  
  .filter-btn {
    width: 100%;
    max-width: 300px;
  }
  
  .comparison-table-wrapper {
    overflow-x: auto;
  }
  
  .comparison-table {
    min-width: 600px;
  }
  
  .step-card {
    padding: 2rem;
  }
  
  .sci-keys {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .footer-links {
    grid-template-columns: 1fr;
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  
  .contact-info {
    flex-direction: column;
    gap: 0.5rem;
  }
  
  .calc-keys {
    gap: 0.5rem;
  }
  
  .calc-btn {
    padding: 1rem;
    font-size: 1.1rem;
    min-height: 55px;
  }
  
  .calc-display {
    font-size: 2rem;
  }
  
  .calc-expression {
    font-size: 0.9rem;
  }
  
  .cta-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .cta-button,
  .primary-btn,
  .secondary-btn {
    width: 100%;
    max-width: 300px;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }
  
  .hero-title,
  .features-hero h1,
  .howto-hero h1 {
    font-size: 2rem;
  }
  
  .section-header h2 {
    font-size: 1.8rem;
  }
  
  .calculator-card,
  .feature-card,
  .tip-card {
    padding: 1.5rem;
  }
  
  .calc-container {
    padding: 1.5rem;
  }
  
  .calc-keys {
    gap: 0.4rem;
  }
  
  .calc-btn {
    padding: 0.8rem;
    font-size: 1rem;
    min-height: 50px;
    border-radius: 10px;
  }
  
  .calc-display {
    font-size: 1.8rem;
  }
  
  .calc-expression {
    font-size: 0.85rem;
  }
  
  .step-card {
    padding: 1.5rem;
  }
  
  .step-number {
    width: 60px;
    height: 60px;
    font-size: 1.5rem;
  }
  
  .faq-question {
    padding: 1.5rem;
  }
  
  .faq-answer {
    padding: 0 1.5rem;
  }
  
  .faq-item.active .faq-answer {
    padding: 0 1.5rem 1.5rem;
  }
  
  .features-list {
    grid-template-columns: 1fr;
  }
  
  .time-inputs {
    grid-template-columns: 1fr;
  }
  
  .card-header {
    flex-direction: column;
    text-align: center;
    gap: 1rem;
  }
  
  .card-icon-wrapper {
    margin: 0 auto;
  }
}

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

button:focus,
input:focus,
select:focus,
textarea:focus,
.nav-link:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* ===== PRINT STYLES ===== */
@media print {
  .navbar,
  .theme-toggle,
  .hero-pattern,
  footer {
    display: none !important;
  }
  
  .hero-section {
    background: white !important;
    color: black !important;
    padding: 2rem 0 !important;
  }
  
  .gradient-text {
    background: black !important;
    -webkit-text-fill-color: black !important;
  }
}

/* ===== INTEREST CALCULATOR MOBILE FIXES ===== */
@media (max-width: 768px) {
  .interest-chart {
    padding: 1rem;
    overflow-x: auto;
  }
  
  #interestChart {
    max-width: 100%;
    height: auto;
  }
  
  .interest-breakdown {
    padding: 1rem;
  }
  
  .result-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.25rem;
    padding: 0.75rem 0;
  }
  
  .result-value {
    font-size: 1.1rem;
  }
}

@media (max-width: 480px) {
  .interest-chart {
    padding: 0.75rem;
    margin: 1rem -0.5rem;
  }
  
  #interestChart {
    width: 100% !important;
    height: 180px !important;
  }
  
  .interest-type {
    flex-direction: column;
  }
  
  .interest-btn {
    width: 100%;
  }
  
  .compound-options {
    padding: 1rem;
    background: var(--background-primary);
    border-radius: 10px;
    border: 1px solid var(--border-color);
  }
  
  .time-inputs {
    grid-template-columns: 1fr;
  }
}

/* Make chart container responsive */
.interest-chart-container {
  position: relative;
  width: 100%;
  max-width: 100%;
  overflow: hidden;
}

.interest-chart-container canvas {
  display: block;
  max-width: 100%;
  height: auto !important;
}

/* Better touch targets for mobile */
@media (max-width: 768px) {
  .form-input,
  .calculate-btn,
  .interest-btn,
  .unit-btn {
    padding: 1.2rem;
    font-size: 1.1rem;
  }
  
  .calculate-btn {
    margin: 1.5rem 0;
  }
}