/* ===== CSS Variables ===== */
:root {
  --color-primary: #302746;
  --color-secondary: #312847;
  --color-accent: #d8c7bb;
  --color-blue: #4fa3f2;
  --color-blue-dark: #3b7cd1;
  --color-white: #ffffff;
  --color-light: #f8f6fa;
  --color-gray: #b0a8b9;
  --color-text: #e8e4ec;
  --color-text-dark: #2d2440;
  --color-card-bg: rgba(255, 255, 255, 0.06);
  --color-card-border: rgba(255, 255, 255, 0.1);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.18);
  --shadow-btn: 0 4px 16px rgba(79, 163, 242, 0.35);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-en: 'Inter', sans-serif;
  --font-body: 'Noto Sans SC', 'Inter', sans-serif;
  --max-width: 1200px;
}

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

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

body {
  font-family: var(--font-en);
  background: var(--color-primary);
  color: var(--color-text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

ul {
  list-style: none;
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 90px 0;
}

.section-title {
  text-align: center;
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--color-white);
}

.section-subtitle {
  text-align: center;
  color: var(--color-gray);
  font-size: 1.1rem;
  margin-bottom: 56px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-blue), var(--color-blue-dark));
  color: var(--color-white);
  box-shadow: var(--shadow-btn);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(79, 163, 242, 0.5);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--color-blue);
  border: 1px solid rgba(79, 163, 242, 0.3);
}

.btn-secondary:hover {
  background: rgba(79, 163, 242, 0.12);
  border-color: var(--color-blue);
}

.btn-large {
  padding: 18px 48px;
  font-size: 1.15rem;
  border-radius: var(--radius-md);
}

/* ===== 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(48, 39, 70, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  padding: 10px 0;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

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

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

.logo img {
  width: 34px;
  height: 34px;
  border-radius: 6px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 0.92rem;
  color: var(--color-gray);
  display: flex;
  align-items: center;
  gap: 6px;
  transition: color var(--transition);
}

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

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

.header-actions {
  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 var(--color-card-border);
  color: var(--color-gray);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  cursor: pointer;
  transition: all var(--transition);
}

.lang-btn:hover {
  color: var(--color-white);
  border-color: rgba(255, 255, 255, 0.25);
}

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

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

.lang-dropdown a {
  display: block;
  padding: 8px 20px;
  font-size: 0.9rem;
  color: var(--color-gray);
  transition: all var(--transition);
}

.lang-dropdown a:hover,
.lang-dropdown a.current {
  color: var(--color-white);
  background: rgba(255, 255, 255, 0.06);
}

/* Mobile Menu */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-white);
  font-size: 1.4rem;
  cursor: pointer;
  padding: 4px;
}

.mobile-nav {
  display: none;
}

/* ===== Hero ===== */
.hero {
  padding: 140px 0 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(79, 163, 242, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

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

.hero h1 span {
  background: linear-gradient(135deg, var(--color-blue), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.2rem;
  color: var(--color-gray);
  max-width: 620px;
  margin: 0 auto 36px;
  position: relative;
}

.hero-btns {
  display: flex;
  gap: 16px;
  justify-content: center;
  position: relative;
}

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

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

.feature-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-md);
  padding: 36px 28px;
  transition: all var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(79, 163, 242, 0.3);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

.feature-card .icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(79, 163, 242, 0.15), rgba(59, 124, 209, 0.08));
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.3rem;
  color: var(--color-blue);
}

.feature-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--color-white);
}

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

.features .cta-wrap {
  text-align: center;
  margin-top: 48px;
}

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

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

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

.use-case-card .icon {
  width: 64px;
  height: 64px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 1.5rem;
}

.use-case-card:nth-child(1) .icon {
  background: rgba(79, 163, 242, 0.15);
  color: var(--color-blue);
}

.use-case-card:nth-child(2) .icon {
  background: rgba(216, 199, 187, 0.15);
  color: var(--color-accent);
}

.use-case-card:nth-child(3) .icon {
  background: rgba(139, 92, 246, 0.15);
  color: #8b5cf6;
}

.use-case-card:nth-child(4) .icon {
  background: rgba(52, 211, 153, 0.15);
  color: #34d399;
}

.use-case-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--color-white);
}

.use-case-card p {
  font-size: 0.9rem;
  color: var(--color-gray);
  line-height: 1.6;
}

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

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

.pricing-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  text-align: center;
  transition: all var(--transition);
  position: relative;
}

.pricing-card.popular {
  border-color: var(--color-blue);
  transform: scale(1.04);
  box-shadow: 0 8px 40px rgba(79, 163, 242, 0.2);
}

.pricing-card .badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, var(--color-blue), var(--color-blue-dark));
  color: var(--color-white);
  padding: 6px 20px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 600;
}

.pricing-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-white);
}

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

.pricing-card .price span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--color-gray);
}

.pricing-card .price-desc {
  color: var(--color-gray);
  font-size: 0.9rem;
  margin-bottom: 28px;
}

.pricing-card ul {
  text-align: left;
  margin-bottom: 32px;
}

.pricing-card ul li {
  padding: 8px 0;
  font-size: 0.92rem;
  color: var(--color-gray);
  display: flex;
  align-items: center;
  gap: 10px;
}

.pricing-card ul li i.fa-check {
  color: var(--color-blue);
}

.pricing-card ul li i.fa-xmark {
  color: #6b5b7b;
}

.pricing-card .btn {
  width: 100%;
  justify-content: center;
}

/* ===== Testimonials ===== */
.testimonials-header {
  text-align: center;
  margin-bottom: 48px;
}

.rating-overview {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  margin-bottom: 12px;
}

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

.rating-stars {
  color: #f59e0b;
  font-size: 1.2rem;
  display: flex;
  gap: 4px;
}

.rating-count {
  color: var(--color-gray);
  font-size: 0.95rem;
}

.testimonials-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 20px;
}

.testimonials-tags span {
  background: rgba(79, 163, 242, 0.1);
  color: var(--color-blue);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  border: 1px solid rgba(79, 163, 242, 0.2);
}

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

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

.testimonial-card {
  flex: 0 0 calc(33.333% - 16px);
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  margin: 0 12px;
}

.testimonial-card .stars {
  color: #f59e0b;
  font-size: 0.9rem;
  margin-bottom: 14px;
  display: flex;
  gap: 3px;
}

.testimonial-card blockquote {
  font-size: 0.95rem;
  color: var(--color-gray);
  line-height: 1.7;
  margin-bottom: 20px;
  font-style: italic;
}

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

.testimonial-card .avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-blue), var(--color-blue-dark));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-white);
  font-weight: 700;
  font-size: 0.95rem;
}

.testimonial-card .author-info h4 {
  font-size: 0.95rem;
  color: var(--color-white);
  font-weight: 600;
}

.testimonial-card .author-info p {
  font-size: 0.82rem;
  color: var(--color-gray);
}

.slider-controls {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 32px;
}

.slider-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  color: var(--color-white);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.slider-btn:hover {
  background: rgba(79, 163, 242, 0.15);
  border-color: var(--color-blue);
}

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

.comparison .container > .fade-in:last-child {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--radius-md);
}

.comparison-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-card-border);
}

.comparison-table thead th {
  background: rgba(255, 255, 255, 0.05);
  padding: 18px 24px;
  text-align: center;
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-white);
  border-bottom: 1px solid var(--color-card-border);
}

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

.comparison-table thead th.highlight {
  background: rgba(79, 163, 242, 0.12);
  color: var(--color-blue);
}

.comparison-table tbody td {
  padding: 16px 24px;
  text-align: center;
  font-size: 0.92rem;
  color: var(--color-gray);
  border-bottom: 1px solid var(--color-card-border);
}

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

.comparison-table tbody td.highlight {
  background: rgba(79, 163, 242, 0.05);
}

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

.comparison-table .check {
  color: var(--color-blue);
  font-size: 1.1rem;
}

.comparison-table .cross {
  color: #6b5b7b;
  font-size: 1.1rem;
}

/* ===== FAQ ===== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

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

.faq-item.active {
  border-color: rgba(79, 163, 242, 0.3);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  background: var(--color-card-bg);
  transition: background var(--transition);
}

.faq-question:hover {
  background: rgba(255, 255, 255, 0.08);
}

.faq-question h3 {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-white);
}

.faq-question i {
  color: var(--color-blue);
  transition: transform var(--transition);
  font-size: 0.9rem;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
}

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

/* ===== Final CTA ===== */
.final-cta {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 50%, rgba(79, 163, 242, 0.15) 100%);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.final-cta::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(79, 163, 242, 0.1) 0%, transparent 70%);
  pointer-events: none;
}

.final-cta h2 {
  font-size: 2.6rem;
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--color-white);
  position: relative;
}

.final-cta p {
  font-size: 1.15rem;
  color: var(--color-gray);
  margin-bottom: 36px;
  position: relative;
}

.final-cta .btn {
  position: relative;
}

/* ===== Footer ===== */
.footer {
  background: rgba(30, 22, 48, 0.6);
  padding: 48px 0 28px;
  border-top: 1px solid var(--color-card-border);
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 28px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-white);
}

.footer-logo img {
  width: 28px;
  height: 28px;
  border-radius: 6px;
}

.footer-links {
  display: flex;
  gap: 28px;
}

.footer-links a {
  color: var(--color-gray);
  font-size: 0.9rem;
  transition: color var(--transition);
}

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

.footer-bottom {
  text-align: center;
  color: #6b5b7b;
  font-size: 0.82rem;
  padding-top: 20px;
  border-top: 1px solid var(--color-card-border);
}

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-blue), var(--color-blue-dark));
  color: var(--color-white);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: all var(--transition);
  box-shadow: var(--shadow-btn);
  z-index: 999;
}

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

.back-to-top:hover {
  transform: translateY(-2px);
}

/* ===== Animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===== 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);
  }

  .testimonial-card {
    flex: 0 0 calc(50% - 16px);
  }
}

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

  .menu-toggle {
    display: flex;
  }

  .mobile-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(48, 39, 70, 0.98);
    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 {
    font-size: 1.3rem;
    color: var(--color-white);
    display: flex;
    align-items: center;
    gap: 10px;
  }

  .mobile-nav .close-btn {
    position: absolute;
    top: 20px;
    right: 24px;
    background: none;
    border: none;
    color: var(--color-white);
    font-size: 1.6rem;
    cursor: pointer;
  }

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

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

  section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 1.7rem;
  }

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

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

  .testimonial-card {
    flex: 0 0 calc(100% - 24px);
  }

  .comparison-table {
    font-size: 0.82rem;
    min-width: 520px;
  }

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

  .footer-content {
    flex-direction: column;
    gap: 20px;
    text-align: center;
  }

  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
  }

  .final-cta h2 {
    font-size: 1.9rem;
  }

  .hero-btns {
    flex-direction: column;
    align-items: center;
  }
}

@media (max-width: 480px) {
  .use-cases-grid {
    grid-template-columns: 1fr;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

  .pricing-card {
    padding: 28px 20px;
  }
}