/* ========== CSS Variables ========== */
:root {
  --color-primary: #18191c;
  --color-secondary: #1d1d20;
  --color-accent: #c4b0ac;
  --color-highlight: #6274a2;
  --color-info: #78a1bf;
  --color-white: #ffffff;
  --color-light: #f0eded;
  --color-muted: #a0a0a8;
  --color-border: rgba(255,255,255,0.08);
  --color-card: #232328;
  --color-card-hover: #2a2a30;
  --gradient-hero: linear-gradient(135deg, #18191c 0%, #1d1d20 50%, #24242a 100%);
  --gradient-cta: linear-gradient(135deg, #6274a2 0%, #78a1bf 100%);
  --gradient-accent: linear-gradient(135deg, #c4b0ac 0%, #78a1bf 100%);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.18);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.25);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.35);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --font-main: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', sans-serif;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

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

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

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

ul {
  list-style: none;
}

h1, h2, h3, h4 {
  line-height: 1.25;
  font-weight: 700;
}

/* ========== Container ========== */
.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== Section ========== */
.section {
  padding: 90px 0;
}

.section-title {
  text-align: center;
  font-size: 2.2rem;
  margin-bottom: 14px;
  color: var(--color-white);
}

.section-subtitle {
  text-align: center;
  font-size: 1.05rem;
  color: var(--color-muted);
  max-width: 600px;
  margin: 0 auto 50px;
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 30px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-cta);
  color: var(--color-white);
  box-shadow: 0 4px 18px rgba(98,116,162,0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(98,116,162,0.5);
}

.btn-secondary {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
}

.btn-secondary:hover {
  background: rgba(196,176,172,0.1);
  transform: translateY(-2px);
}

.btn-large {
  padding: 17px 42px;
  font-size: 1.12rem;
}

/* ========== 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(24, 25, 28, 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: 1.3rem;
  font-weight: 700;
  color: var(--color-white);
}

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

.nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav a {
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 0.92rem;
  color: var(--color-muted);
  transition: all var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav a:hover {
  color: var(--color-white);
  background: rgba(255,255,255,0.05);
}

.nav a i {
  font-size: 0.82rem;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

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

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: 8px;
  font-size: 0.88rem;
  color: var(--color-muted);
  background: transparent;
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition);
}

.lang-btn:hover {
  color: var(--color-white);
  border-color: rgba(255,255,255,0.15);
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 6px;
  min-width: 160px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition);
  box-shadow: var(--shadow-md);
  z-index: 100;
}

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

.lang-dropdown a {
  display: block;
  padding: 9px 14px;
  border-radius: 6px;
  font-size: 0.88rem;
  color: var(--color-muted);
  transition: all var(--transition);
}

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

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  z-index: 1001;
}

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

.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 Nav */
.mobile-nav {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(24, 25, 28, 0.97);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  z-index: 999;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
}

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

.mobile-nav a {
  font-size: 1.2rem;
  padding: 14px 30px;
  color: var(--color-muted);
  transition: color var(--transition);
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.mobile-lang-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-top: 16px;
  padding: 0 20px;
}

.mobile-lang-list a {
  font-size: 0.9rem;
  padding: 8px 16px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
}

/* ========== Hero ========== */
.hero {
  min-height: 520px;
  display: flex;
  align-items: center;
  padding-top: 100px;
  padding-bottom: 60px;
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -40%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(98,116,162,0.12) 0%, transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -15%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(120,161,191,0.08) 0%, transparent 70%);
  border-radius: 50%;
}

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

.hero h1 {
  font-size: 3.2rem;
  margin-bottom: 18px;
  color: var(--color-white);
  letter-spacing: -0.5px;
}

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

.hero p {
  font-size: 1.18rem;
  color: var(--color-muted);
  max-width: 580px;
  margin: 0 auto 36px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

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

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

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

.feature-card:hover {
  transform: translateY(-4px);
  background: var(--color-card-hover);
  border-color: rgba(255,255,255,0.12);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 20px;
  background: rgba(98,116,162,0.12);
  color: var(--color-info);
}

.feature-card h3 {
  font-size: 1.12rem;
  margin-bottom: 10px;
  color: var(--color-white);
}

.feature-card p {
  font-size: 0.93rem;
  color: var(--color-muted);
  line-height: 1.65;
}

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

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

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

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

.usecase-icon {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin: 0 auto 18px;
}

.usecase-card:nth-child(1) .usecase-icon {
  background: rgba(196,176,172,0.15);
  color: var(--color-accent);
}

.usecase-card:nth-child(2) .usecase-icon {
  background: rgba(98,116,162,0.15);
  color: var(--color-highlight);
}

.usecase-card:nth-child(3) .usecase-icon {
  background: rgba(120,161,191,0.15);
  color: var(--color-info);
}

.usecase-card:nth-child(4) .usecase-icon {
  background: rgba(196,176,172,0.12);
  color: var(--color-accent);
}

.usecase-card h3 {
  font-size: 1.05rem;
  margin-bottom: 10px;
  color: var(--color-white);
}

.usecase-card p {
  font-size: 0.9rem;
  color: var(--color-muted);
}

/* ========== 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);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  transition: all var(--transition);
  position: relative;
}

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

.pricing-card.popular {
  border-color: var(--color-highlight);
  box-shadow: 0 0 30px rgba(98,116,162,0.15);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-cta);
  color: var(--color-white);
  padding: 5px 20px;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 600;
  white-space: nowrap;
}

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

.pricing-price {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 6px;
}

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

.pricing-desc {
  font-size: 0.9rem;
  color: var(--color-muted);
  margin-bottom: 28px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--color-border);
}

.pricing-features {
  margin-bottom: 32px;
}

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

.pricing-features li i {
  font-size: 0.8rem;
  width: 20px;
  text-align: center;
}

.pricing-features li i.fa-check {
  color: #5cb97a;
}

.pricing-features li i.fa-xmark {
  color: #7a7a82;
}

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

/* ========== Testimonials ========== */
.testimonials-header {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

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

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

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

.rating-count {
  font-size: 0.9rem;
  color: var(--color-muted);
}

.rating-bars {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 200px;
}

.rating-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--color-muted);
}

.rating-bar-fill {
  flex: 1;
  height: 6px;
  background: rgba(255,255,255,0.06);
  border-radius: 3px;
  overflow: hidden;
}

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

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

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

.testimonial-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
}

.testimonial-stars {
  color: #f5a623;
  font-size: 0.9rem;
  margin-bottom: 14px;
}

.testimonial-text {
  font-size: 0.93rem;
  color: var(--color-light);
  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-cta);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-white);
}

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

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

.testimonial-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-top: 40px;
}

.testimonial-tag {
  padding: 8px 18px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--color-border);
  border-radius: 50px;
  font-size: 0.85rem;
  color: var(--color-muted);
}

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

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

.comparison-table th,
.comparison-table td {
  padding: 18px 24px;
  text-align: center;
  font-size: 0.93rem;
  border-bottom: 1px solid var(--color-border);
}

.comparison-table th {
  background: rgba(255,255,255,0.03);
  color: var(--color-white);
  font-weight: 600;
}

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

.comparison-table td {
  color: var(--color-muted);
}

.highlight-col {
  background: rgba(98,116,162,0.06);
}

.comparison-table .fa-check {
  color: #5cb97a;
}

.comparison-table .fa-xmark {
  color: #7a7a82;
}

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

/* ========== 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-card);
  transition: all var(--transition);
}

.faq-item:hover {
  border-color: rgba(255,255,255,0.12);
}

.faq-question {
  width: 100%;
  padding: 20px 24px;
  background: transparent;
  border: none;
  color: var(--color-white);
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-family: var(--font-main);
}

.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);
}

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

.faq-answer p {
  padding: 0 24px 20px;
  font-size: 0.93rem;
  color: var(--color-muted);
  line-height: 1.7;
}

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

.final-cta::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -20%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255,255,255,0.06) 0%, transparent 70%);
  border-radius: 50%;
}

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

.final-cta h2 {
  font-size: 2.4rem;
  color: var(--color-white);
  margin-bottom: 14px;
}

.final-cta p {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.8);
  margin-bottom: 36px;
}

.final-cta .btn {
  background: var(--color-white);
  color: var(--color-primary);
  font-weight: 700;
  box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

.final-cta .btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(0,0,0,0.3);
}

/* ========== Footer ========== */
.footer {
  background: var(--color-primary);
  border-top: 1px solid var(--color-border);
  padding: 48px 0 32px;
}

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

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

.footer-brand .logo {
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.88rem;
  color: var(--color-muted);
  line-height: 1.65;
}

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

.footer-col h4 {
  font-size: 0.9rem;
  color: var(--color-white);
  margin-bottom: 16px;
  font-weight: 600;
}

.footer-col a {
  display: block;
  font-size: 0.88rem;
  color: var(--color-muted);
  padding: 5px 0;
  transition: color var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: 24px;
  text-align: center;
  font-size: 0.82rem;
  color: var(--color-muted);
}

/* ========== Back to Top ========== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-cta);
  color: var(--color-white);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition);
  box-shadow: var(--shadow-md);
  z-index: 900;
}

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

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

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

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

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

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

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

  .testimonials-slider .testimonial-card:nth-child(3) {
    display: none;
  }
}

@media (max-width: 768px) {
  .nav {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .mobile-nav {
    display: flex;
  }

  .header-actions .btn-primary {
    display: none;
  }

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

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

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

  .section {
    padding: 60px 0;
  }

  .section-title {
    font-size: 1.75rem;
  }

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

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

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

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

  .testimonials-slider .testimonial-card:nth-child(3) {
    display: block;
  }

  .comparison-table {
    font-size: 0.82rem;
  }

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

  .footer-content {
    flex-direction: column;
  }

  .footer-links {
    gap: 32px;
    flex-wrap: wrap;
  }

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

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.8rem;
  }

  .pricing-grid {
    max-width: 100%;
  }

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

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