/* ==========================================================================
   To link云 Landing Page Design System & Stylesheet (v2.1)
   Light Theme - Single Source of Truth Tokenized Architecture
   ========================================================================== */

:root {
  /* Color Palette - Light Theme with Vibrant Accent Shades */
  --color-bg: #f8fafc;
  --color-bg-alt: #f1f5f9;
  --color-surface: #ffffff;
  --color-surface-glass: rgba(255, 255, 255, 0.85);
  --color-border: #e2e8f0;
  --color-border-hover: #cbd5e1;

  --color-text-primary: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #64748b;
  --color-text-inverse: #ffffff;

  --color-accent: #4f46e5;
  --color-accent-hover: #4338ca;
  --color-accent-light: #eef2ff;
  --color-accent-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  --color-accent-gradient-hover: linear-gradient(135deg, #4338ca 0%, #6d28d9 100%);

  --color-success: #10b981;
  --color-success-bg: #ecfdf5;
  --color-warning: #f59e0b;
  --color-warning-bg: #fffbeb;
  --color-danger: #ef4444;

  /* Elevation & Shadows */
  --elevation-1: 0 1px 3px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.03);
  --elevation-2: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --elevation-3: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.03);
  --elevation-glow: 0 10px 30px rgba(79, 70, 229, 0.2);

  /* Border Radii */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* Layout Spacing */
  --container-max-width: 1200px;
  --nav-height: 72px;
  --sticky-bar-height: 70px;
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--font-family);
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* Focus styles for Accessibility */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Base Typography & Elements */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  color: var(--color-text-primary);
  line-height: 1.25;
  font-weight: 700;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s ease, opacity 0.2s ease;
}

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

img, svg {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

/* Container */
.cx-x9w, .container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Glassmorphism & Panel Cards */
.gp-k6l, .glass-panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--elevation-1);
  transition: transform 0.28s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.28s ease, border-color 0.28s ease;
}

.gp-k6l:hover, .glass-panel:hover {
  box-shadow: var(--elevation-3);
  border-color: var(--color-border-hover);
}

/* Header & Nav */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
}

.hx-v2m, .header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.lz-8b, .logo {
  font-size: 24px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--color-text-primary);
  background: var(--color-accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: var(--color-accent); /* Fallback */
  display: flex;
  align-items: center;
  gap: 8px;
}

.nx-k3q, .nav-menu {
  display: flex;
  gap: 32px;
  align-items: center;
}

.nx-k3q a, .nav-menu a {
  font-weight: 500;
  font-size: 15px;
  color: var(--color-text-secondary);
}

.nx-k3q a:hover, .nav-menu a:hover {
  color: var(--color-accent);
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--color-text-primary);
  padding: 8px;
}

/* Buttons */
.bx-t4, .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 26px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 15px;
  text-align: center;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.24s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.24s ease, background 0.24s ease, color 0.24s ease;
  white-space: nowrap;
}

.bx-p9y, .btn-primary {
  background: var(--color-accent-gradient);
  color: var(--color-text-inverse) !important;
  box-shadow: var(--elevation-glow);
}

.bx-p9y:hover, .btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(79, 70, 229, 0.35);
  background: var(--color-accent-gradient-hover);
}

.btn-secondary, .btn-ghost {
  background: var(--color-surface);
  color: var(--color-text-primary) !important;
  border: 1px solid var(--color-border);
}

.btn-secondary:hover, .btn-ghost:hover {
  background: var(--color-bg-alt);
  border-color: var(--color-border-hover);
  transform: translateY(-2px);
}

/* Hero Section */
.h-r8x {
  padding: calc(var(--nav-height) + 60px) 0 80px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
}

.ht-v7z {
  flex: 1;
  max-width: 620px;
}

.ht-v7z h1 {
  font-size: 46px;
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 20px;
  color: var(--color-text-primary);
  line-height: 1.15;
}

.ht-v7z p {
  font-size: 18px;
  color: var(--color-text-secondary);
  margin-bottom: 32px;
  line-height: 1.6;
}

/* Hero Trust Pills (C1 Component) */
.hero-trust-pills {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

.trust-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-accent-light);
  color: var(--color-accent-hover);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 600;
  border: 1px solid rgba(79, 70, 229, 0.15);
}

/* CTA Sub-Microcopy */
.cta-trust-microcopy {
  margin-top: 14px;
  font-size: 13px;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Hero Visual SVG Component */
.hv-m2w {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  min-height: 380px;
}

.hero-svg-visual {
  width: 100%;
  max-width: 460px;
  height: auto;
}

/* Section Common */
.sx-a1b {
  padding: 80px 0;
}

.sx-a1b:nth-child(even) {
  background: var(--color-bg-alt);
}

.st-c2d {
  text-align: center;
  font-size: 32px;
  letter-spacing: -0.5px;
  margin-bottom: 48px;
  color: var(--color-text-primary);
}

/* Feature Cards Grid */
.gx-e3f {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.fc-g4h {
  padding: 36px 28px;
  text-align: left;
  background: var(--color-surface);
}

.fi-i5j {
  font-size: 42px;
  margin-bottom: 20px;
  display: inline-block;
  background: var(--color-accent-light);
  width: 64px;
  height: 64px;
  line-height: 64px;
  text-align: center;
  border-radius: var(--radius-md);
}

.fc-g4h h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.fc-g4h p {
  color: var(--color-text-secondary);
  font-size: 15px;
}

/* Streaming & AI Support Block */
.ma-m7n {
  padding: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  background: var(--color-surface);
}

.mc-o8p {
  flex: 1;
}

.mc-o8p h3 {
  font-size: 26px;
  margin-bottom: 16px;
}

.mc-o8p p {
  color: var(--color-text-secondary);
  margin-bottom: 24px;
  font-size: 16px;
}

.ml-q9r {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.tx-s0t {
  background: var(--color-accent-light);
  color: var(--color-accent);
  padding: 6px 16px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 600;
  border: 1px solid rgba(79, 70, 229, 0.12);
}

/* Pricing Section & Promo Banner (C3 Component) */
.pricing-promo-banner {
  background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
  border: 1px solid #f59e0b;
  color: #78350f;
  padding: 14px 24px;
  border-radius: var(--radius-md);
  text-align: center;
  font-weight: 600;
  font-size: 15px;
  margin-bottom: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  box-shadow: var(--elevation-1);
}

.pricing-gx-e3f {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  align-items: stretch;
}

.pc-w2x {
  padding: 40px 32px;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  position: relative;
}

.pc-w2x.pp-y3z {
  border: 2px solid var(--color-accent);
  box-shadow: var(--elevation-3);
  transform: scale(1.02);
}

.pb-a4b {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-accent-gradient);
  color: #ffffff;
  padding: 4px 18px;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.pc-w2x h3 {
  font-size: 22px;
  margin-bottom: 12px;
}

.pr-c5d {
  font-size: 44px;
  font-weight: 800;
  color: var(--color-text-primary);
  margin: 16px 0 24px;
}

.pr-c5d span {
  font-size: 15px;
  color: var(--color-text-muted);
  font-weight: normal;
}

.pf-e6f {
  list-style: none;
  margin-bottom: 32px;
  flex: 1;
}

.pf-e6f li {
  margin-bottom: 12px;
  padding-left: 26px;
  position: relative;
  color: var(--color-text-secondary);
  font-size: 14px;
}

.pf-e6f li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-success);
  font-weight: 800;
}

.pricing-card-footer {
  margin-top: auto;
}

.pricing-refund-guarantee {
  text-align: center;
  font-size: 12px;
  color: var(--color-text-muted);
  margin-top: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

/* Articles Directory Grid */
.articles-gx-e3f {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.ac-i8j {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.28s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.28s ease;
}

.ac-i8j:hover {
  transform: translateY(-6px);
  box-shadow: var(--elevation-3);
  border-color: var(--color-border-hover);
}

.ai-k9l {
  height: 160px;
  background: var(--color-accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
  border-bottom: 1px solid var(--color-border);
}

.ac-m0n {
  padding: 24px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.am-o1p {
  font-size: 12px;
  font-weight: 700;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.ac-m0n h3 {
  font-size: 17px;
  margin-bottom: 10px;
  color: var(--color-text-primary);
  line-height: 1.4;
}

.ac-m0n p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Reviews Grid */
.reviews-gx-e3f {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.rc-s3t {
  padding: 32px;
  background: var(--color-surface);
}

.rt-u4v {
  font-size: 15px;
  color: var(--color-text-secondary);
  margin-bottom: 20px;
  font-style: italic;
  line-height: 1.6;
}

.ra-w5x {
  font-weight: 700;
  font-size: 14px;
  color: var(--color-text-primary);
}

/* FAQ Accordion / Box */
.fl-y6z {
  max-width: 840px;
  margin: 0 auto;
}

.fi-a7b {
  padding: 24px;
  margin-bottom: 16px;
  background: var(--color-surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

.fi-a7b h3, .fi-a7b h4 {
  font-size: 18px;
  margin-bottom: 8px;
  color: var(--color-text-primary);
}

.fi-a7b p {
  color: var(--color-text-secondary);
  font-size: 15px;
}

/* Footer */
footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 48px 0;
  text-align: center;
}

.fl-c8d {
  display: flex;
  justify-content: center;
  gap: 36px;
  margin-bottom: 20px;
}

.fl-c8d a {
  color: var(--color-text-secondary);
  font-size: 14px;
  font-weight: 500;
}

.fl-c8d a:hover {
  color: var(--color-accent);
}

.cy-e9f {
  color: var(--color-text-muted);
  font-size: 13px;
}

/* Auxiliary Subpage General Layout */
.page-header {
  padding: calc(var(--nav-height) + 40px) 0 40px;
  text-align: center;
}

.page-header h1 {
  font-size: 36px;
  margin-bottom: 12px;
}

.page-header p {
  color: var(--color-text-secondary);
  font-size: 16px;
}

.page-content {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  padding: 48px;
  margin-bottom: 80px;
}

.page-content h2 {
  font-size: 24px;
  margin: 32px 0 16px;

}

.page-content h2:first-child {
  margin-top: 0;
}

.page-content p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
  font-size: 15px;
  line-height: 1.7;
}

.page-content ul {
  margin-bottom: 24px;
  padding-left: 24px;
  color: var(--color-text-secondary);
}

.page-content li {
  margin-bottom: 8px;
}

/* Mobile Bottom Sticky CTA Bar (C4 Component) */
.mobile-sticky-bar {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: var(--sticky-bar-height);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-top: 1px solid var(--color-border);
  z-index: 990;
  padding: 10px 16px;
  padding-bottom: max(10px, env(safe-area-inset-bottom));
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.08);
}

.mobile-sticky-inner {
  display: flex;
  gap: 12px;
  height: 100%;
  align-items: center;
}

.mobile-sticky-inner a {
  flex: 1;
  height: 46px;
  font-size: 14px;
  padding: 0;
}

/* Body Padding Buffer for Sticky Bar on Mobile */
@media (max-width: 768px) {
  body {
    padding-bottom: calc(var(--sticky-bar-height) + env(safe-area-inset-bottom));
  }
  .mobile-sticky-bar {
    display: block;
  }
}

/* Exit-Intent Modal Popup (C5 Component) */
.exit-modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.exit-modal-overlay.is-active {
  display: flex;
  opacity: 1;
}

.exit-modal-card {
  background: var(--color-surface);
  width: 100%;
  max-width: 480px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--elevation-3);
  padding: 36px 32px;
  position: relative;
  transform: scale(0.95);
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  text-align: center;
}

.exit-modal-overlay.is-active .exit-modal-card {
  transform: scale(1);
}

.exit-modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: var(--color-bg-alt);
  border: none;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  font-size: 18px;
  cursor: pointer;
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s ease;
}

.exit-modal-close:hover {
  background: var(--color-border);
}

.exit-modal-title {
  font-size: 24px;
  margin-bottom: 10px;
  color: var(--color-text-primary);
}

.exit-modal-desc {
  font-size: 15px;
  color: var(--color-text-secondary);
  margin-bottom: 20px;
}

.exit-code-box {
  background: var(--color-accent-light);
  border: 2px dashed var(--color-accent);
  border-radius: var(--radius-md);
  padding: 16px;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.exit-code-text {
  font-size: 22px;
  font-weight: 800;
  color: var(--color-accent-hover);
  letter-spacing: 1px;
  font-family: monospace;
}

.exit-copy-btn {
  background: var(--color-accent);
  color: #ffffff;
  border: none;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s ease;
}

.exit-copy-btn:hover {
  background: var(--color-accent-hover);
}

.exit-modal-cta {
  width: 100%;
  padding: 14px;
  font-size: 16px;
  margin-bottom: 12px;
}

.exit-modal-trust {
  font-size: 12px;
  color: var(--color-text-muted);
}

/* Responsive Media Queries */
@media (max-width: 992px) {
  .gx-e3f, .pricing-gx-e3f, .articles-gx-e3f, .reviews-gx-e3f {
    grid-template-columns: repeat(2, 1fr);
  }

  .pc-w2x.pp-y3z {
    transform: none;
  }

  .ma-m7n {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 768px) {
  /* Header Mobile Responsiveness: Hide redundant header CTA button to prevent layout squeezing */
  header .bx-p9y {
    display: none;
  }

  .nx-k3q {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    background: var(--color-surface);
    flex-direction: column;
    padding: 20px 24px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--elevation-3);
    z-index: 1001;
  }

  .nx-k3q.is-open {
    display: flex;
  }

  .mobile-nav-toggle {
    display: block;
  }

  /* Hero Section Mobile Alignment & Symmetry Fix */
  .h-r8x {
    flex-direction: column;
    text-align: center;
    padding-top: calc(var(--nav-height) + 20px);
    padding-bottom: 32px;
    gap: 28px;
  }

  .ht-v7z {
    max-width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .ht-v7z h1 {
    font-size: 25px;
    line-height: 1.35;
    text-align: center;
    margin-bottom: 16px;
    word-break: break-word;
  }

  .ht-v7z p {
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 24px;
    text-align: center;
    color: var(--color-text-secondary);
  }

  .hero-trust-pills {
    justify-content: center;
    gap: 6px 8px;
    width: 100%;
    margin-bottom: 20px;
  }

  .trust-pill {
    font-size: 12px;
    padding: 4px 10px;
    text-align: center;
  }

  /* Hero CTA Buttons on Mobile: Full-width stacked & centered container */
  .ht-v7z .hero-cta-group {
    width: 100%;
    max-width: 340px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: stretch;
  }

  .ht-v7z .hero-cta-group .bx-t4 {
    width: 100%;
    justify-content: center;
    padding: 14px 20px;
    font-size: 15px;
  }

  .cta-trust-microcopy {
    justify-content: center;
    text-align: center;
    margin-top: 16px;
  }

  .hv-m2w {
    min-height: 240px;
    width: 100%;
  }

  /* Pricing Promo Banner Stacking on Mobile */
  .pricing-promo-banner {
    flex-direction: column;
    text-align: center;
    font-size: 14px;
    padding: 12px 16px;
    gap: 6px;
  }

  /* Grid Layouts to Single Column Stack */
  .gx-e3f, .pricing-gx-e3f, .articles-gx-e3f, .reviews-gx-e3f {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .pc-w2x {
    padding: 28px 20px;
  }

  .ma-m7n {
    padding: 28px 20px;
  }

  .mc-o8p h2 {
    font-size: 20px;
  }

  .page-header {
    padding-top: calc(var(--nav-height) + 20px);
  }

  .page-header h1 {
    font-size: 26px;
  }

  .page-content {
    padding: 24px 18px;
  }
}

/* Reduced Motion for Accessibility */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}