/* ============================================
   WeTrans 2026 — AI Translation Platform
   Dark Premium — Linear / Vercel / OpenAI style
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

:root {
  /* Deep dark palette */
  --bg-primary: #09090b;
  --bg-secondary: #0f0f13;
  --bg-tertiary: #16161d;
  --bg-card: #131318;
  --bg-card-hover: #1a1a22;

  /* Layered text */
  --text-primary: #f4f4f5;
  --text-secondary: #a1a1aa;
  --text-muted: #52525b;

  /* Electric accent — luminous indigo */
  --accent-primary: #818cf8;
  --accent-hover: #6366f1;
  --accent-glow: rgba(129, 140, 248, 0.15);
  --accent-glow-strong: rgba(129, 140, 248, 0.25);
  --accent-subtle: rgba(129, 140, 248, 0.08);

  /* Borders — near invisible */
  --border-color: rgba(255, 255, 255, 0.06);
  --border-hover: rgba(255, 255, 255, 0.1);
  --border-accent: rgba(129, 140, 248, 0.25);

  /* Shadows — ethereal glows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 40px rgba(129, 140, 248, 0.08);

  /* Corners */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;

  /* Typography */
  --font-sans: 'Inter', -apple-system, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;

  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11';
}

a { text-decoration: none; color: inherit; }

/* ── Utilities ── */
.serif-italic {
  background: linear-gradient(135deg, var(--accent-primary), #c084fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 700;
  font-style: normal;
}

.container { max-width: 1120px; margin: 0 auto; padding: 0 32px; }

/* ── Section Headers ── */
.section-header { text-align: center; margin-bottom: 64px; }

.section-badge {
  display: inline-block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-weight: 600;
  color: var(--accent-primary);
  background: var(--accent-subtle);
  border: 1px solid rgba(129, 140, 248, 0.12);
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 20px;
}

.section-title {
  font-size: clamp(30px, 3.5vw, 44px);
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 16px;
  line-height: 1.12;
  letter-spacing: -0.035em;
}

.section-desc {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ══════════════════════════════════
   Navigation — frosted dark glass
   ══════════════════════════════════ */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  padding: 16px 0;
  transition: var(--transition);
  z-index: 1000;
  background: transparent;
}

.navbar.scrolled {
  background: rgba(9, 9, 11, 0.8);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  padding: 12px 0;
  border-bottom: 1px solid var(--border-color);
}

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.04em;
  color: var(--text-primary);
}

.logo-symbol {
  font-size: 18px;
  color: var(--accent-primary);
}

.logo-ai {
  font-size: 12px;
  color: var(--accent-primary);
  font-weight: 600;
  margin-left: 3px;
  padding: 2px 7px;
  background: var(--accent-subtle);
  border: 1px solid rgba(129, 140, 248, 0.12);
  border-radius: 4px;
  letter-spacing: 0.04em;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
}

.nav-links a:hover { color: var(--text-primary); text-shadow: 0 0 12px var(--accent-glow); }

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.lang-switcher {
  display: flex;
  align-items: center;
  gap: 4px;
  border-right: 1px solid var(--border-color);
  padding-right: 12px;
  margin-right: 4px;
}

.lang-btn {
  background: none;
  border: none;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  transition: var(--transition);
}

.lang-btn.active { color: var(--text-primary); }
.lang-sep { color: var(--border-hover); font-size: 10px; }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  font-family: var(--font-sans);
}

.btn-primary {
  background: var(--accent-primary);
  color: #0f0f13;
  border: 1px solid var(--accent-primary);
  box-shadow: 0 1px 2px rgba(0,0,0,0.3), 0 0 16px var(--accent-glow);
}

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  box-shadow: 0 4px 20px var(--accent-glow-strong);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-hover);
}

.btn-outline:hover {
  border-color: var(--text-secondary);
  background: rgba(255,255,255,0.03);
}

.btn-ghost {
  background: none;
  border: none;
  color: var(--text-secondary);
  padding: 8px 12px;
}

.btn-ghost:hover { color: var(--text-primary); }
.btn-xl { padding: 14px 36px; font-size: 16px; border-radius: var(--radius-md); }
.btn-block { width: 100%; }

/* ══════════════════════════════════
   Hero — with luminous gradient glow
   ══════════════════════════════════ */
.hero {
  padding: 160px 0 100px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

/* Ambient gradient glow */
.hero::before {
  content: '';
  position: absolute;
  top: -120px; left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  background: radial-gradient(ellipse at center,
    rgba(129, 140, 248, 0.12) 0%,
    rgba(168, 85, 247, 0.06) 40%,
    transparent 70%
  );
  pointer-events: none;
  z-index: 0;
}

/* Fine grid texture */
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  z-index: 0;
  mask-image: radial-gradient(ellipse 60% 60% at 50% 40%, black, transparent);
  -webkit-mask-image: radial-gradient(ellipse 60% 60% at 50% 40%, black, transparent);
}

.hero > * { position: relative; z-index: 1; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 100px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.hero-title {
  font-size: clamp(42px, 5.5vw, 68px);
  font-weight: 800;
  letter-spacing: -0.045em;
  line-height: 1.06;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.hero-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 580px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

.hero-buttons, .hero-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 0;
  padding-bottom: 48px;
}

.btn-lg { padding: 12px 28px; font-size: 15px; }

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 56px;
  padding-top: 48px;
  border-top: 1px solid var(--border-color);
}

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

.stat-number {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.stat-label {
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 500;
  margin-top: 4px;
}

.stat-divider {
  width: 1px;
  background: var(--border-color);
}

/* ── Mockup ── */
.hero-mockup {
  max-width: 860px;
  margin: 72px auto 0;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  background: var(--bg-card);
}

.mockup-header {
  height: 44px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  padding: 0 16px;
}

.mockup-dots span {
  display: inline-block;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: rgba(255,255,255,0.08);
  margin-right: 6px;
}

.mockup-body {
  display: flex;
  height: 320px;
}

.mockup-sidebar {
  width: 200px;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  padding: 16px 12px;
}

.mockup-sidebar-item {
  padding: 8px 12px;
  font-size: 13px;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  margin-bottom: 4px;
}

.mockup-sidebar-item.active {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  font-weight: 500;
}

.mockup-content {
  flex: 1;
  padding: 24px;
  font-size: 15px;
}

.mockup-row {
  display: flex;
  gap: 24px;
  margin-bottom: 16px;
  padding: 12px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
}

.mockup-row.active-row {
  background: var(--accent-subtle);
  border-color: rgba(129,140,248,0.1);
}

.mockup-cell { flex: 1; line-height: 1.6; }
.mockup-cell.source { color: var(--text-muted); }
.mockup-cell.target { color: var(--text-primary); }

.cursor {
  display: inline-block;
  width: 2px;
  height: 1.2em;
  background: var(--accent-primary);
  vertical-align: middle;
  animation: blink 1s step-end infinite;
}

@keyframes blink { 50% { opacity: 0; } }

/* ══════════════════════════════════
   Features — floating glass cards
   ══════════════════════════════════ */
.features {
  padding: 120px 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.feature-card {
  padding: 28px 24px;
  border-radius: var(--radius-md);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.feature-card:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.feature-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--accent-subtle);
  border: 1px solid rgba(129, 140, 248, 0.08);
  color: var(--accent-primary);
  margin-bottom: 16px;
  transition: var(--transition);
}

.feature-card:hover .feature-icon {
  background: var(--accent-glow);
  border-color: var(--border-accent);
  box-shadow: 0 0 20px var(--accent-glow);
}

.feature-icon svg { width: 22px; height: 22px; }

.feature-card h3 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.feature-card p {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ══════════════════════════════════
   Screenshots / Preview
   ══════════════════════════════════ */
.screenshots { padding: 120px 0; }

.screenshots-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 48px;
}

.screenshot-tab {
  background: transparent;
  border: 1px solid var(--border-color);
  padding: 8px 20px;
  border-radius: 100px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-sans);
}

.screenshot-tab:hover {
  border-color: var(--border-hover);
  color: var(--text-secondary);
}

.screenshot-tab.active {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: #0f0f13;
  font-weight: 600;
}

.screenshot-display { display: flex; justify-content: center; }

.screenshot-card {
  display: none;
  width: 100%;
  max-width: 800px;
  animation: fadeUp 0.3s ease forwards;
}

.screenshot-card.active { display: block; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.screenshot-placeholder {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 72px 40px;
  text-align: center;
  box-shadow: var(--shadow-md);
}

.screenshot-placeholder h3 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.screenshot-placeholder p {
  color: var(--text-secondary);
  font-size: 15px;
}

/* ══════════════════════════════════
   Pricing — elevated dark cards
   ══════════════════════════════════ */
.pricing {
  padding: 120px 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.pricing-grid.pricing-grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

.pricing-card {
  padding: 32px 24px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  position: relative;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

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

.pricing-card.featured {
  border-color: var(--border-accent);
  box-shadow: var(--shadow-lg), 0 0 60px var(--accent-glow);
  transform: translateY(-4px);
}

/* Glowing top accent bar on featured */
.pricing-card.featured::before {
  content: '';
  position: absolute;
  top: -1px; left: 20%; right: 20%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-primary), transparent);
  border-radius: 0 0 2px 2px;
}

.pricing-header h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 4px;
  letter-spacing: -0.01em;
}

.pricing-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.pricing-price { margin-bottom: 20px; }

.price-currency {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-secondary);
  vertical-align: top;
  margin-right: 2px;
  line-height: 1.3;
}

.price-amount {
  font-size: 52px;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
  letter-spacing: -0.04em;
}

.price-period {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 500;
}

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
  flex: 1;
}

.pricing-features li {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.pricing-features .chk {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-subtle);
  border: 1px solid rgba(129, 140, 248, 0.1);
  flex-shrink: 0;
}

.pricing-features .chk::after {
  content: '';
  width: 8px;
  height: 5px;
  border-left: 1.5px solid var(--accent-primary);
  border-bottom: 1.5px solid var(--accent-primary);
  transform: rotate(-45deg);
  margin-top: -1px;
}

.pricing-card.featured .chk {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
}

.pricing-card.featured .chk::after {
  border-color: #0f0f13;
}

/* ── Billing Toggle ── */
.billing-toggle {
  display: inline-flex;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 100px;
  padding: 4px;
  gap: 2px;
}

.billing-opt {
  padding: 8px 24px;
  border: none;
  border-radius: 100px;
  background: transparent;
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-sans);
}

.billing-opt.active {
  background: var(--accent-primary);
  color: #0f0f13;
  box-shadow: 0 2px 12px var(--accent-glow-strong);
}

.billing-opt:hover:not(.active) {
  color: var(--text-secondary);
  background: rgba(255,255,255,0.03);
}

/* ── Credits Badge ── */
.credits-badge {
  display: inline-block;
  padding: 6px 14px;
  background: var(--accent-subtle);
  border: 1px solid rgba(129, 140, 248, 0.1);
  border-radius: 100px;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-primary);
  margin-bottom: 20px;
}

/* ══════════════════════════════════
   FAQ
   ══════════════════════════════════ */
.faq { padding: 120px 0; }

.faq-grid {
  max-width: 680px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--border-color);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 0;
  text-align: left;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  font-family: var(--font-sans);
  transition: var(--transition);
}

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

.faq-arrow {
  color: var(--text-muted);
  transition: var(--transition);
  font-size: 18px;
}

.faq-item.open .faq-arrow { transform: rotate(45deg); }

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

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

.faq-answer-inner { padding-bottom: 24px; }

.faq-answer p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ══════════════════════════════════
   Footer
   ══════════════════════════════════ */
.footer {
  padding: 40px 0;
  border-top: 1px solid var(--border-color);
}

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

.footer-brand {
  display: flex;
  align-items: center;
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

/* ══════════════════════════════════
   Download Section
   ══════════════════════════════════ */
.download { padding: 100px 0; }
.download-grid { text-align: center; }
.download-main { margin-bottom: 40px; }

.download-version {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 12px;
}

.download-platforms {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 24px;
}

.platform-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 24px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-card);
  transition: var(--transition);
}

.platform-link:hover {
  border-color: var(--border-accent);
  box-shadow: 0 0 20px var(--accent-glow);
}

.platform-icon { font-size: 20px; }

.platform-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}

.platform-ext {
  font-size: 12px;
  color: var(--text-muted);
}

.download-note { font-size: 13px; color: var(--text-muted); }
.download-note a { color: var(--accent-primary); text-decoration: underline; }

/* ══════════════════════════════════
   Responsive
   ══════════════════════════════════ */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid, .pricing-grid.pricing-grid-4 { grid-template-columns: repeat(2, 1fr); max-width: 720px; margin: 0 auto; }
  .pricing-card.featured { transform: none; }
}

@media (max-width: 768px) {
  .nav-links, .nav-actions > a { display: none; }
  .hero-title { font-size: 36px; }
  .hero { padding: 120px 0 80px; }
  .features-grid { grid-template-columns: 1fr; }
  .stat-divider { display: none; }
  .hero-stats { flex-direction: column; gap: 24px; }
  .mockup-sidebar { display: none; }
  .footer-bottom { flex-direction: column; gap: 16px; text-align: center; }
  .download-platforms { flex-direction: column; align-items: center; }
  .btn-xl { padding: 14px 28px; font-size: 15px; }
  .container { padding: 0 20px; }
  .section-header { margin-bottom: 48px; }
  .features, .screenshots, .pricing, .faq { padding: 80px 0; }
}

@media (max-width: 480px) {
  .hero-buttons, .hero-actions { flex-direction: column; align-items: stretch; padding: 0 20px; }
  .hero-title { font-size: 28px; }
  .pricing-grid, .pricing-grid.pricing-grid-4 { grid-template-columns: 1fr; max-width: 420px; }
}