/* ===== CSS Variables ===== */
:root {
  --color-primary: #0d0e1a;
  --color-secondary: #151729;
  --color-surface: #1a1c32;
  --color-accent: #4a8ef5;
  --color-warm: #e8734a;
  --color-text: #e8e9f0;
  --color-text-light: #8b8ea5;
  --color-white: #fff;
  --color-border: #282a42;
  --gradient-primary: linear-gradient(135deg, #0d0e1a 0%, #1a1c32 50%, #0d0e1a 100%);
  --gradient-accent: linear-gradient(135deg, #4a8ef5 0%, #6c5ce7 100%);
  --gradient-hero: linear-gradient(160deg, #0d0e1a 0%, #1a1c32 40%, #151729 100%);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --font-body: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', sans-serif;
  --font-heading: 'Inter', 'Noto Sans SC', sans-serif;
  --transition: 0.3s ease;
}

/* ===== 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-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

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

ul, ol {
  list-style: none;
}

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

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

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

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  padding: 16px 0;
  transition: all var(--transition);
  background: transparent;
}

.header.scrolled {
  background: rgba(13, 14, 26, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.06);
  padding: 10px 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-white);
  transition: color var(--transition);
}

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

.logo img {
  width: 32px;
  height: 32px;
  border-radius: 6px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.65);
  display: flex;
  align-items: center;
  gap: 6px;
  transition: color var(--transition);
}

.nav-links a:hover {
  color: var(--color-white);
}

.header.scrolled .nav-links a {
  color: rgba(255, 255, 255, 0.65);
}

.header.scrolled .nav-links a:hover {
  color: var(--color-white);
}

.nav-links a i {
  font-size: 0.8rem;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* Language Switcher */
.lang-switcher {
  position: relative;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  background: none;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.7);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-body);
}

.lang-btn:hover {
  border-color: rgba(255, 255, 255, 0.4);
  color: var(--color-white);
}

.header.scrolled .lang-btn {
  border-color: rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.7);
}

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

.lang-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  min-width: 160px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition);
  border: 1px solid var(--color-border);
  overflow: hidden;
}

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

.lang-dropdown a {
  display: block;
  padding: 10px 16px;
  font-size: 0.85rem;
  color: var(--color-text-light);
  transition: all var(--transition);
}

.lang-dropdown a:hover,
.lang-dropdown a.active {
  background: rgba(74, 142, 245, 0.1);
  color: var(--color-accent);
}

.btn-cta-header {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 20px;
  background: var(--color-accent);
  color: var(--color-white);
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all var(--transition);
}

.btn-cta-header:hover {
  background: #3a7de0;
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(74, 142, 245, 0.4);
  color: var(--color-white);
}

/* Mobile Menu */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

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

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

.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);
}

/* ===== Hero Section ===== */
.hero {
  position: relative;
  min-height: 520px;
  display: flex;
  align-items: center;
  background: var(--gradient-hero);
  padding: 120px 0 80px;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(74, 142, 245, 0.15) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(232, 115, 74, 0.1) 0%, transparent 70%);
  border-radius: 50%;
}

.hero .container {
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 16px;
  line-height: 1.2;
  animation: fadeInUp 0.8s ease;
}

.hero h1 span {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .subtitle {
  font-size: 1.15rem;
  color: rgba(255, 255, 255, 0.6);
  max-width: 600px;
  margin: 0 auto 32px;
  animation: fadeInUp 0.8s ease 0.2s both;
}

.btn-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 36px;
  background: var(--color-accent);
  color: var(--color-white);
  border-radius: 50px;
  font-size: 1.05rem;
  font-weight: 600;
  transition: all var(--transition);
  animation: fadeInUp 0.8s ease 0.4s both;
}

.btn-cta:hover {
  background: #3a7de0;
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(74, 142, 245, 0.4);
  color: var(--color-white);
}

/* ===== Section Common ===== */
.section {
  padding: 80px 0;
}

.section-alt {
  background: var(--color-secondary);
}

.section-title {
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 12px;
}

.section-desc {
  text-align: center;
  color: var(--color-text-light);
  max-width: 600px;
  margin: 0 auto 48px;
  font-size: 1rem;
}

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

.feature-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  text-align: center;
  transition: all var(--transition);
  border: 1px solid var(--color-border);
}

.section-alt .feature-card {
  background: rgba(26, 28, 50, 0.6);
  border-color: var(--color-border);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(74, 142, 245, 0.3);
}

.feature-icon {
  width: 56px;
  height: 56px;
  background: rgba(74, 142, 245, 0.12);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 1.4rem;
  color: var(--color-accent);
}

.feature-card h3 {
  font-size: 1.1rem;
  color: var(--color-white);
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.6;
}

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

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 12px 28px;
  border: 2px solid var(--color-accent);
  color: var(--color-accent);
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition);
}

.btn-secondary:hover {
  background: var(--color-accent);
  color: var(--color-white);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(74, 142, 245, 0.3);
}

/* ===== Use Cases ===== */
.usecases-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.usecase-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 28px 20px;
  text-align: center;
  transition: all var(--transition);
  border: 1px solid var(--color-border);
  position: relative;
  overflow: hidden;
}

.usecase-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
}

.usecase-card:nth-child(1)::before { background: var(--color-accent); }
.usecase-card:nth-child(2)::before { background: var(--color-warm); }
.usecase-card:nth-child(3)::before { background: #6c5ce7; }
.usecase-card:nth-child(4)::before { background: #4ecdc4; }

.usecase-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(74, 142, 245, 0.2);
}

.usecase-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.usecase-card:nth-child(1) .usecase-icon { color: var(--color-accent); }
.usecase-card:nth-child(2) .usecase-icon { color: var(--color-warm); }
.usecase-card:nth-child(3) .usecase-icon { color: #6c5ce7; }
.usecase-card:nth-child(4) .usecase-icon { color: #4ecdc4; }

.usecase-card h3 {
  font-size: 1.05rem;
  color: var(--color-white);
  margin-bottom: 8px;
}

.usecase-card p {
  font-size: 0.85rem;
  color: var(--color-text-light);
  line-height: 1.6;
}

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

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

.pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(74, 142, 245, 0.2);
}

.pricing-card.popular {
  border: 2px solid var(--color-accent);
  transform: scale(1.03);
  background: linear-gradient(180deg, rgba(74, 142, 245, 0.08) 0%, var(--color-surface) 100%);
}

.pricing-card.popular:hover {
  transform: scale(1.03) translateY(-4px);
  box-shadow: 0 8px 40px rgba(74, 142, 245, 0.25);
}

.popular-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-accent);
  color: var(--color-white);
  padding: 4px 20px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 600;
  white-space: nowrap;
}

.pricing-card .plan-name {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 8px;
}

.pricing-card .plan-price {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 4px;
}

.pricing-card .plan-price span {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--color-text-light);
}

.pricing-card .plan-desc {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.pricing-features {
  list-style: none;
  margin-bottom: 28px;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  font-size: 0.9rem;
  color: var(--color-text);
}

.pricing-features li i.fa-check {
  color: var(--color-accent);
  font-size: 0.8rem;
}

.pricing-features li i.fa-xmark {
  color: #454768;
  font-size: 0.8rem;
}

.pricing-features li.disabled {
  color: #454768;
}

.btn-pricing {
  display: block;
  text-align: center;
  padding: 12px 24px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition);
  width: 100%;
}

.btn-pricing-outline {
  border: 2px solid var(--color-accent);
  color: var(--color-accent);
  background: transparent;
}

.btn-pricing-outline:hover {
  background: var(--color-accent);
  color: var(--color-white);
}

.btn-pricing-filled {
  background: var(--color-accent);
  color: var(--color-white);
  border: 2px solid var(--color-accent);
}

.btn-pricing-filled:hover {
  background: #3a7de0;
  border-color: #3a7de0;
  color: var(--color-white);
}

/* ===== Testimonials ===== */
.testimonials-header {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.rating-overview {
  text-align: center;
}

.rating-score {
  font-size: 3rem;
  font-weight: 800;
  color: var(--color-white);
  line-height: 1;
}

.rating-stars {
  color: #f5a623;
  font-size: 1.1rem;
  margin: 8px 0 4px;
}

.rating-count {
  font-size: 0.85rem;
  color: var(--color-text-light);
}

.rating-bars {
  width: 240px;
}

.rating-bar-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 4px;
  font-size: 0.8rem;
  color: var(--color-text-light);
}

.rating-bar-row span:first-child {
  width: 16px;
  text-align: right;
}

.rating-bar {
  flex: 1;
  height: 6px;
  background: var(--color-border);
  border-radius: 3px;
  overflow: hidden;
}

.rating-bar-fill {
  height: 100%;
  background: #f5a623;
  border-radius: 3px;
}

.rating-bar-row span:last-child {
  width: 32px;
}

.testimonials-carousel {
  position: relative;
  overflow: hidden;
}

.testimonials-track {
  display: flex;
  transition: transform 0.5s ease;
}

.testimonial-card {
  min-width: 100%;
  padding: 0 24px;
}

@media (min-width: 768px) {
  .testimonial-card {
    min-width: 50%;
  }
}

@media (min-width: 1024px) {
  .testimonial-card {
    min-width: 33.333%;
  }
}

.testimonial-inner {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 28px;
  border: 1px solid var(--color-border);
  height: 100%;
}

.testimonial-stars {
  color: #f5a623;
  margin-bottom: 12px;
}

.testimonial-text {
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 16px;
  font-style: italic;
}

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

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

.testimonial-name {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--color-white);
}

.testimonial-role {
  font-size: 0.8rem;
  color: var(--color-text-light);
}

.carousel-controls {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 24px;
}

.carousel-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  color: var(--color-text-light);
}

.carousel-btn:hover {
  background: var(--color-accent);
  color: var(--color-white);
  border-color: var(--color-accent);
}

.testimonial-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 32px;
}

.testimonial-tag {
  padding: 6px 16px;
  background: rgba(74, 142, 245, 0.1);
  color: var(--color-accent);
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 500;
  border: 1px solid rgba(74, 142, 245, 0.15);
}

/* ===== Comparison ===== */
.comparison-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-surface);
  min-width: 600px;
}

.comparison-table th,
.comparison-table td {
  padding: 16px 20px;
  text-align: center;
  font-size: 0.9rem;
}

.comparison-table thead th {
  background: var(--color-border);
  color: var(--color-white);
  font-weight: 600;
}

.comparison-table thead th:first-child {
  text-align: left;
  border-radius: var(--radius-md) 0 0 0;
}

.comparison-table thead th:last-child {
  border-radius: 0 var(--radius-md) 0 0;
}

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

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

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

.comparison-table tbody td:first-child {
  text-align: left;
  font-weight: 500;
  color: var(--color-text);
}

.comparison-table tbody td {
  color: var(--color-text-light);
}

.comparison-table tbody td.highlight {
  background: rgba(74, 142, 245, 0.06);
  color: var(--color-text);
}

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

.comparison-table .cross {
  color: #454768;
}

/* ===== FAQ ===== */
.faq-list {
  max-width: 760px;
  margin: 0 auto;
}

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

.faq-item:hover {
  box-shadow: var(--shadow-sm);
  border-color: rgba(74, 142, 245, 0.2);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-white);
  gap: 16px;
}

.faq-question i {
  font-size: 0.8rem;
  transition: transform var(--transition);
  flex-shrink: 0;
  color: var(--color-accent);
}

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

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

.faq-answer-inner {
  padding: 0 24px 18px;
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 300px;
}

/* ===== Final CTA ===== */
.final-cta {
  background: linear-gradient(135deg, #0d0e1a 0%, #1a2a4a 50%, #0d0e1a 100%);
  padding: 80px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.final-cta::before {
  content: '';
  position: absolute;
  top: -40%;
  right: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(74, 142, 245, 0.15) 0%, transparent 70%);
  border-radius: 50%;
}

.final-cta .container {
  position: relative;
  z-index: 1;
}

.final-cta h2 {
  font-size: 2.2rem;
  color: var(--color-white);
  margin-bottom: 12px;
}

.final-cta p {
  color: rgba(255, 255, 255, 0.6);
  font-size: 1.1rem;
  margin-bottom: 32px;
}

.btn-cta-lg {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 44px;
  background: var(--color-accent);
  color: var(--color-white);
  border-radius: 50px;
  font-size: 1.1rem;
  font-weight: 700;
  transition: all var(--transition);
}

.btn-cta-lg:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 40px rgba(74, 142, 245, 0.4);
  background: #3a7de0;
  color: var(--color-white);
}

/* ===== Footer ===== */
.footer {
  background: #080910;
  color: rgba(255, 255, 255, 0.5);
  padding: 48px 0 24px;
  border-top: 1px solid var(--color-border);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: start;
  gap: 40px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.footer-brand {
  max-width: 280px;
}

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

.footer-brand p {
  font-size: 0.85rem;
  line-height: 1.6;
}

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

.footer-links-group a {
  display: block;
  font-size: 0.85rem;
  padding: 4px 0;
  color: rgba(255, 255, 255, 0.45);
  transition: color var(--transition);
}

.footer-links-group a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 20px;
  text-align: center;
  font-size: 0.8rem;
}

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background: var(--color-accent);
  color: var(--color-white);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition);
  z-index: 999;
  box-shadow: 0 4px 20px rgba(74, 142, 245, 0.3);
}

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

.back-to-top:hover {
  background: #3a7de0;
  transform: translateY(-3px);
}

/* ===== Mobile Navigation Overlay ===== */
.mobile-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(13, 14, 26, 0.97);
  backdrop-filter: blur(20px);
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 24px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
}

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

.mobile-nav a {
  color: var(--color-white);
  font-size: 1.3rem;
  font-weight: 600;
  padding: 8px 0;
}

.mobile-nav a:hover {
  color: var(--color-accent);
}

.mobile-nav .lang-mobile {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 24px;
}

.mobile-nav .lang-mobile a {
  font-size: 0.95rem;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.5);
}

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

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

  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 420px;
    margin: 0 auto;
  }

  .pricing-card.popular {
    transform: none;
  }

  .pricing-card.popular:hover {
    transform: translateY(-4px);
  }
}

@media (max-width: 768px) {
  .nav-links,
  .nav-right .btn-cta-header,
  .nav-right .lang-switcher {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero .subtitle {
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.6rem;
  }

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

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

  .testimonials-header {
    flex-direction: column;
    gap: 20px;
  }

  .footer-content {
    flex-direction: column;
    gap: 28px;
  }

  .final-cta h2 {
    font-size: 1.6rem;
  }

  .section {
    padding: 60px 0;
  }

  .hero {
    padding: 100px 0 60px;
    min-height: auto;
  }
}