/* ==================== CSS Variables ==================== */
:root {
  --color-primary: #3c518c;
  --color-secondary: #3c518e;
  --color-accent: #e8eef1;
  --color-dark: #1d1d1d;
  --color-muted: #92adc5;
  --color-white: #ffffff;
  --color-bg: #f7f9fb;
  --color-card: #ffffff;
  --color-border: #dde4ea;
  --color-text: #333333;
  --color-text-light: #6b7b8d;
  --gradient-primary: linear-gradient(135deg, #3c518c 0%, #5a6fba 100%);
  --gradient-hero: linear-gradient(160deg, #1d1d1d 0%, #2a3a6a 50%, #3c518c 100%);
  --gradient-cta: linear-gradient(135deg, #3c518c 0%, #4e65a8 50%, #5a6fba 100%);
  --shadow-sm: 0 2px 8px rgba(60, 81, 140, 0.08);
  --shadow-md: 0 4px 20px rgba(60, 81, 140, 0.12);
  --shadow-lg: 0 8px 40px rgba(60, 81, 140, 0.16);
  --shadow-card: 0 2px 16px rgba(60, 81, 140, 0.07);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-heading: 'Inter', 'Noto Sans SC', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', sans-serif;
}

/* ==================== Reset & Base ==================== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition);
}

ul, ol {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

button {
  border: none;
  cursor: pointer;
  font-family: inherit;
  background: none;
}

/* ==================== Utility ==================== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section-title {
  text-align: center;
  margin-bottom: 16px;
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--color-dark);
  font-family: var(--font-heading);
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-light);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto 48px;
  line-height: 1.6;
}

section {
  padding: 80px 0;
}

/* ==================== Animations ==================== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

.fade-in-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.fade-in-right {
  opacity: 0;
  transform: translateX(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* ==================== Header ==================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: all var(--transition);
  background: transparent;
}

.header.scrolled {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-sm);
  padding: 10px 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-white);
  font-family: var(--font-heading);
  transition: color var(--transition);
}

.header.scrolled .logo {
  color: var(--color-dark);
}

.logo img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.85);
  transition: all var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link:hover {
  color: var(--color-white);
  background: rgba(255, 255, 255, 0.1);
}

.header.scrolled .nav-link {
  color: var(--color-text);
}

.header.scrolled .nav-link:hover {
  color: var(--color-primary);
  background: var(--color-accent);
}

.nav-link i {
  font-size: 0.85rem;
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  background: var(--color-white);
  color: var(--color-primary);
  border-radius: var(--radius-xl);
  font-weight: 600;
  font-size: 0.92rem;
  transition: all var(--transition);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
}

.header-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.header.scrolled .header-cta {
  background: var(--gradient-primary);
  color: var(--color-white);
}

/* Language Switcher */
.lang-switcher {
  position: relative;
  margin-left: 8px;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.85);
  cursor: pointer;
  transition: all var(--transition);
}

.lang-btn:hover {
  color: var(--color-white);
  background: rgba(255, 255, 255, 0.1);
}

.header.scrolled .lang-btn {
  color: var(--color-text);
}

.header.scrolled .lang-btn:hover {
  color: var(--color-primary);
  background: var(--color-accent);
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 160px;
  padding: 8px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition);
  z-index: 100;
}

.lang-switcher:hover .lang-dropdown,
.lang-dropdown.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-dropdown a {
  display: block;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--color-text);
  transition: all var(--transition);
}

.lang-dropdown a:hover,
.lang-dropdown a.active {
  background: var(--color-accent);
  color: var(--color-primary);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}

.hamburger span {
  width: 24px;
  height: 2px;
  background: var(--color-white);
  border-radius: 2px;
  transition: all var(--transition);
}

.header.scrolled .hamburger span {
  background: var(--color-dark);
}

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

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

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Menu */
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(29, 29, 29, 0.97);
  backdrop-filter: blur(20px);
  z-index: 999;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.4s ease;
}

.mobile-menu.active {
  opacity: 1;
  visibility: visible;
}

.mobile-menu a {
  font-size: 1.2rem;
  color: var(--color-white);
  padding: 12px 32px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

.mobile-menu a:hover {
  background: rgba(255, 255, 255, 0.1);
}

.mobile-menu .mobile-cta {
  margin-top: 16px;
  padding: 14px 40px;
  background: var(--gradient-primary);
  border-radius: var(--radius-xl);
  font-weight: 600;
  font-size: 1.1rem;
}

.mobile-lang-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.mobile-lang-list a {
  font-size: 0.9rem;
  padding: 8px 16px;
}

/* ==================== Hero ==================== */
.hero {
  background: var(--gradient-hero);
  padding: 140px 0 80px;
  position: relative;
  overflow: hidden;
  min-height: 520px;
  display: flex;
  align-items: center;
}

.hero::before {
  content: '';
  position: absolute;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(90, 111, 186, 0.2) 0%, transparent 70%);
  top: -200px;
  right: -100px;
  border-radius: 50%;
}

.hero::after {
  content: '';
  position: absolute;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(146, 173, 197, 0.15) 0%, transparent 70%);
  bottom: -100px;
  left: -50px;
  border-radius: 50%;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 760px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 3.2rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 20px;
  font-family: var(--font-heading);
  line-height: 1.2;
}

.hero h1 span {
  background: linear-gradient(135deg, #a8bfff 0%, #92adc5 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.2rem;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 40px;
  background: var(--color-white);
  color: var(--color-primary);
  border-radius: var(--radius-xl);
  font-size: 1.1rem;
  font-weight: 700;
  transition: all var(--transition);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.2);
}

.hero-cta:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 36px rgba(0, 0, 0, 0.25);
}

.hero-badges {
  display: flex;
  gap: 24px;
  justify-content: center;
  margin-top: 40px;
  flex-wrap: wrap;
}

.hero-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.9rem;
}

.hero-badge i {
  color: var(--color-muted);
}

/* ==================== Features ==================== */
.features {
  background: var(--color-bg);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 40px;
}

.feature-card {
  background: var(--color-card);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  transition: all var(--transition);
  border: 1px solid transparent;
  box-shadow: var(--shadow-card);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(60, 81, 140, 0.1);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.3rem;
  color: var(--color-primary);
  transition: all var(--transition);
}

.feature-card:hover .feature-icon {
  background: var(--gradient-primary);
  color: var(--color-white);
}

.feature-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--color-dark);
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.6;
}

.features .center-cta {
  text-align: center;
}

.secondary-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-xl);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition);
}

.secondary-cta:hover {
  background: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-2px);
}

/* ==================== Use Cases ==================== */
.use-cases {
  background: var(--color-white);
}

.use-cases-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.use-case-card {
  text-align: center;
  padding: 36px 24px;
  border-radius: var(--radius-md);
  transition: all var(--transition);
  border: 1px solid var(--color-border);
}

.use-case-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.use-case-card:nth-child(1) { border-top: 3px solid #3c518c; }
.use-case-card:nth-child(2) { border-top: 3px solid #92adc5; }
.use-case-card:nth-child(3) { border-top: 3px solid #5a6fba; }
.use-case-card:nth-child(4) { border-top: 3px solid #3c518e; }

.use-case-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 1.5rem;
  color: var(--color-primary);
}

.use-case-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--color-dark);
}

.use-case-card p {
  font-size: 0.92rem;
  color: var(--color-text-light);
  line-height: 1.6;
}

/* ==================== Pricing ==================== */
.pricing {
  background: var(--color-bg);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: start;
}

.pricing-card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  border: 1px solid var(--color-border);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.pricing-card:hover {
  box-shadow: var(--shadow-md);
}

.pricing-card.popular {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-lg);
  transform: scale(1.03);
}

.popular-tag {
  position: absolute;
  top: 16px;
  right: -32px;
  background: var(--gradient-primary);
  color: var(--color-white);
  padding: 4px 40px;
  font-size: 0.78rem;
  font-weight: 600;
  transform: rotate(45deg);
  letter-spacing: 0.5px;
}

.pricing-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-dark);
}

.pricing-card .price {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--color-primary);
  margin-bottom: 4px;
  font-family: var(--font-heading);
}

.pricing-card .price-period {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.pricing-features {
  margin-bottom: 28px;
}

.pricing-features li {
  padding: 8px 0;
  font-size: 0.93rem;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 10px;
}

.pricing-features li i.fa-check {
  color: #22c55e;
  font-size: 0.85rem;
}

.pricing-features li i.fa-xmark {
  color: #cbd5e1;
  font-size: 0.85rem;
}

.pricing-cta {
  display: block;
  text-align: center;
  padding: 14px 24px;
  border-radius: var(--radius-xl);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition);
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
}

.pricing-cta:hover {
  background: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-2px);
}

.pricing-card.popular .pricing-cta {
  background: var(--gradient-primary);
  color: var(--color-white);
  border-color: transparent;
}

.pricing-card.popular .pricing-cta:hover {
  box-shadow: 0 4px 20px rgba(60, 81, 140, 0.4);
}

/* ==================== Testimonials ==================== */
.testimonials {
  background: var(--color-white);
}

.testimonials-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 40px;
  margin-bottom: 48px;
  padding: 28px 32px;
  background: var(--color-accent);
  border-radius: var(--radius-lg);
}

.testimonials-stat {
  text-align: center;
}

.testimonials-stat .stat-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-primary);
  font-family: var(--font-heading);
}

.testimonials-stat .stat-label {
  font-size: 0.88rem;
  color: var(--color-text-light);
}

.stars {
  color: #f59e0b;
  font-size: 1rem;
  letter-spacing: 2px;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial-card {
  background: var(--color-bg);
  border-radius: var(--radius-md);
  padding: 28px;
  border: 1px solid var(--color-border);
}

.testimonial-card .stars {
  margin-bottom: 14px;
}

.testimonial-card blockquote {
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 18px;
  font-style: italic;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.testimonial-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-white);
  font-weight: 700;
  font-size: 0.9rem;
}

.testimonial-info strong {
  display: block;
  font-size: 0.92rem;
  color: var(--color-dark);
}

.testimonial-info span {
  font-size: 0.82rem;
  color: var(--color-text-light);
}

.testimonial-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 36px;
}

.testimonial-tag {
  padding: 6px 16px;
  background: var(--color-accent);
  color: var(--color-primary);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 500;
}

/* ==================== Comparison ==================== */
.comparison {
  background: var(--color-bg);
}

.comparison-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: var(--color-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.comparison-table th,
.comparison-table td {
  padding: 16px 20px;
  text-align: center;
  font-size: 0.93rem;
  border-bottom: 1px solid var(--color-border);
}

.comparison-table thead th {
  background: var(--color-dark);
  color: var(--color-white);
  font-weight: 600;
  font-size: 0.95rem;
}

.comparison-table thead th:first-child {
  text-align: left;
}

.comparison-table thead th.highlight {
  background: var(--color-primary);
}

.comparison-table tbody td:first-child {
  text-align: left;
  font-weight: 600;
  color: var(--color-dark);
}

.comparison-table tbody td.highlight {
  background: rgba(60, 81, 140, 0.04);
}

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

.comparison-table .check {
  color: var(--color-primary);
  font-weight: 700;
}

.comparison-table .cross {
  color: #cbd5e1;
}

/* ==================== FAQ ==================== */
.faq {
  background: var(--color-white);
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  transition: all var(--transition);
}

.faq-item:hover {
  border-color: var(--color-muted);
}

.faq-item.active {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-dark);
  gap: 16px;
  transition: all var(--transition);
}

.faq-question:hover {
  color: var(--color-primary);
}

.faq-question i {
  font-size: 0.85rem;
  color: var(--color-muted);
  transition: transform var(--transition);
  flex-shrink: 0;
}

.faq-item.active .faq-question i {
  transform: rotate(180deg);
  color: var(--color-primary);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease;
}

.faq-answer-inner {
  padding: 0 24px 20px;
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ==================== Final CTA ==================== */
.final-cta {
  background: var(--gradient-cta);
  padding: 80px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.final-cta::before {
  content: '';
  position: absolute;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.06) 0%, transparent 70%);
  top: -200px;
  left: -100px;
  border-radius: 50%;
}

.final-cta h2 {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}

.final-cta p {
  font-size: 1.15rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 36px;
  position: relative;
  z-index: 1;
}

.final-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 18px 48px;
  background: var(--color-white);
  color: var(--color-primary);
  border-radius: var(--radius-xl);
  font-size: 1.15rem;
  font-weight: 700;
  transition: all var(--transition);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.15);
  position: relative;
  z-index: 1;
}

.final-cta-btn:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.2);
}

/* ==================== Footer ==================== */
.footer {
  background: var(--color-dark);
  padding: 48px 0 24px;
  color: rgba(255, 255, 255, 0.6);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: start;
  gap: 32px;
  margin-bottom: 32px;
}

.footer-brand {
  max-width: 300px;
}

.footer-brand .logo {
  color: var(--color-white);
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.9rem;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  gap: 48px;
}

.footer-col h4 {
  color: var(--color-white);
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.footer-col a {
  display: block;
  padding: 4px 0;
  font-size: 0.88rem;
  color: rgba(255, 255, 255, 0.5);
  transition: color var(--transition);
}

.footer-col a:hover {
  color: var(--color-white);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
}

/* ==================== Back to Top ==================== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: var(--color-white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: all var(--transition);
  z-index: 900;
  cursor: pointer;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

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

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

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

  .pricing-card.popular {
    transform: scale(1);
  }

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

@media (max-width: 768px) {
  html {
    font-size: 15px;
  }

  .nav,
  .header-cta,
  .lang-switcher {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .mobile-menu {
    display: flex;
  }

  .hero {
    padding: 120px 0 60px;
    min-height: auto;
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  .hero p {
    font-size: 1.05rem;
  }

  section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 1.8rem;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .use-cases-grid {
    grid-template-columns: 1fr;
  }

  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin: 0 auto;
  }

  .testimonials-header {
    gap: 24px;
    padding: 24px 20px;
  }

  .testimonials-grid {
    grid-template-columns: 1fr;
  }

  .comparison-table {
    font-size: 0.85rem;
  }

  .comparison-table th,
  .comparison-table td {
    padding: 12px 10px;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer-brand {
    max-width: 100%;
  }

  .footer-links {
    flex-direction: column;
    gap: 28px;
    width: 100%;
  }

  .final-cta h2 {
    font-size: 1.8rem;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.9rem;
  }

  .hero-badges {
    flex-wrap: nowrap;
    justify-content: center;
    align-items: center;
    gap: 10px;
    margin-top: 28px;
  }

  .hero-badge {
    flex: 1 1 0;
    justify-content: center;
    font-size: 0.72rem;
    gap: 5px;
    text-align: center;
    white-space: nowrap;
  }

  .testimonials-header {
    flex-direction: column;
  }
}