/* ==================================================
   星维机场 - 星标坐标系统 Design System CSS
   Color Palette:
   - Page Background: #F7F9FC
   - Pure White Surface: #FFFFFF
   - Main Text: #17212B
   - Body Text: #56616D
   - Secondary Text: #7C8894
   - Deep Navy Blue 1: #243C55
   - Deep Navy Blue 2: #1D3145
   - Slate Blue: #59758D
   - Medium Gray Blue: #7890A3
   - Fog Blue: #EAF0F5
   - Light Fog Blue: #F1F5F8
   - Amber: #B78742
   - Dark Amber: #946A32
   - Light Amber: #F6EFE4
   - Border: #D9E1E8
   - Reference Line: #C6D0D9
================================================== */

:root {
  --bg-page: #F7F9FC;
  --surface: #FFFFFF;
  --surface-soft: #F1F5F8;
  --text-main: #17212B;
  --text-body: #56616D;
  --text-secondary: #7C8894;
  --navy-deep: #243C55;
  --navy-deep-2: #1D3145;
  --slate-blue: #59758D;
  --gray-blue-mid: #7890A3;
  --fog-blue: #EAF0F5;
  --light-fog-blue: #F1F5F8;
  --amber: #B78742;
  --dark-amber: #946A32;
  --light-amber: #F6EFE4;
  --border: #D9E1E8;
  --guide-line: #C6D0D9;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --transition-fast: 0.2s ease;
  --shadow-subtle: 0 12px 28px rgba(23, 33, 43, 0.025);
  --shadow-focus: 0 0 0 3px rgba(36, 60, 85, 0.15);
}

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

html {
  font-family: var(--font-family);
  font-size: 16px;
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.75;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  color: var(--text-body);
}

/* Accessibility & Focus States */
:focus-visible {
  outline: 2px solid var(--navy-deep);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--navy-deep);
  color: #FFFFFF;
  padding: 0.5rem 1rem;
  z-index: 1000;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: top var(--transition-fast);
}
.skip-link:focus {
  top: 1rem;
}

/* Typography Standards */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 600;
  line-height: 1.3;
}

h1 {
  font-size: clamp(2.2rem, 4vw, 3.4rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.6rem, 2.5vw, 2.25rem);
  letter-spacing: -0.01em;
}

h3 {
  font-size: clamp(1.2rem, 1.8vw, 1.5rem);
}

p {
  line-height: 1.8;
  color: var(--text-body);
}

a {
  color: var(--navy-deep);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header Navbar */
.site-header {
  height: 70px;
  background-color: var(--bg-page);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo {
  display: flex;
  align-items: center;
}

.brand-title-group {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.1;
}

.brand-subtext {
  font-size: 0.75rem;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  font-size: 0.95rem;
  color: var(--text-main);
  padding: 0.5rem 0;
  position: relative;
  font-weight: 500;
}

.nav-link:hover, .nav-link.active {
  color: var(--navy-deep);
}

.nav-link.active::after, .nav-link:hover::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--navy-deep);
}

.cta-btn-header {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  background-color: var(--navy-deep);
  color: #FFFFFF !important;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.55rem 1.1rem;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.cta-btn-header:hover {
  background-color: var(--navy-deep-2);
  transform: translateY(-1px);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: 1px solid var(--border);
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--text-main);
}

.mobile-nav-menu {
  display: none;
  position: absolute;
  top: 70px;
  left: 0;
  width: 100%;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 1rem 1.5rem;
  flex-direction: column;
  gap: 0.75rem;
  box-shadow: 0 10px 20px rgba(0,0,0,0.05);
}

.mobile-nav-menu.is-open {
  display: flex;
}

/* ==================================================
   Hero Section - Demand Positioning Plane (需求定位平面)
================================================== */
.hero-section {
  background-color: var(--bg-page);
  padding: 2.5rem 0 3.5rem 0;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
}

.hero-grid {
  display: grid;
  grid-template-columns: 240px 1fr 240px;
  grid-template-rows: auto 1fr auto;
  grid-template-areas:
    "top top top"
    "left center right"
    "bottom bottom bottom";
  gap: 1.25rem;
  align-items: center;
  min-height: 600px;
  position: relative;
}

/* Decorative reference lines */
.hero-ref-line-h {
  position: absolute;
  left: 5%;
  right: 5%;
  top: 50%;
  height: 1px;
  background-color: var(--guide-line);
  opacity: 0.6;
  pointer-events: none;
}

.hero-ref-line-v {
  position: absolute;
  top: 5%;
  bottom: 5%;
  left: 50%;
  width: 1px;
  background-color: var(--guide-line);
  opacity: 0.6;
  pointer-events: none;
}

/* Hero Directions */
.hero-dir {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.1rem 1.25rem;
  position: relative;
  z-index: 2;
  transition: border-color var(--transition-fast);
}

.hero-dir:hover {
  border-color: var(--slate-blue);
}

.hero-dir-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--slate-blue);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.hero-dir-title::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  background-color: var(--amber);
  border-radius: 50%;
}

.hero-dir-items {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.25rem;
  line-height: 1.4;
}

.hero-dir-sub {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.35;
}

.hero-dir-top {
  grid-area: top;
  max-width: 680px;
  margin: 0 auto;
  width: 100%;
  text-align: center;
}
.hero-dir-top .hero-dir-title { justify-content: center; }

.hero-dir-left { grid-area: left; }
.hero-dir-right { grid-area: right; }

.hero-dir-bottom {
  grid-area: bottom;
  max-width: 680px;
  margin: 0 auto;
  width: 100%;
  text-align: center;
}
.hero-dir-bottom .hero-dir-title { justify-content: center; }

/* Hero Central Core */
.hero-center {
  grid-area: center;
  text-align: center;
  padding: 2rem 1.5rem;
  position: relative;
  z-index: 2;
}

.hero-brand-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--navy-deep);
  background-color: var(--fog-blue);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.25rem;
}

.hero-main-motto {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--navy-deep);
  margin-bottom: 0.85rem;
  line-height: 1.4;
}

.hero-h1 {
  font-size: clamp(1.75rem, 3.2vw, 2.6rem);
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
  line-height: 1.3;
}

.hero-body-text {
  font-size: 1rem;
  color: var(--text-body);
  max-width: 620px;
  margin: 0 auto 1.75rem auto;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background-color: var(--navy-deep);
  color: #FFFFFF !important;
  font-size: 1rem;
  font-weight: 600;
  padding: 0.75rem 1.6rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--navy-deep);
  transition: all var(--transition-fast);
  cursor: pointer;
}
.btn-primary:hover {
  background-color: var(--navy-deep-2);
  border-color: var(--navy-deep-2);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background-color: transparent;
  color: var(--navy-deep) !important;
  font-size: 1rem;
  font-weight: 600;
  padding: 0.75rem 1.4rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--navy-deep);
  transition: all var(--transition-fast);
  cursor: pointer;
}
.btn-secondary:hover {
  background-color: var(--fog-blue);
}

.hero-review-link {
  font-size: 0.9rem;
  color: var(--slate-blue);
  display: inline-block;
  margin-top: 0.5rem;
}

/* Generic Section Container */
.content-section {
  padding: 4.5rem 0;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-page);
}

.content-section.bg-white {
  background-color: var(--surface);
}

.section-header {
  margin-bottom: 2.5rem;
}

.section-num {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--amber);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 0.35rem;
  display: block;
}

.section-title {
  margin-bottom: 0.75rem;
}

.section-direct-answer {
  font-size: 1.05rem;
  color: var(--text-body);
  max-width: 860px;
  line-height: 1.8;
  background-color: var(--surface-soft);
  padding: 1.1rem 1.35rem;
  border-left: 3px solid var(--navy-deep);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-top: 1rem;
}

/* Section 01: Demand Type UI */
.demand-matrix {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.demand-type-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative;
}

.demand-type-tag {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--slate-blue);
  background: var(--fog-blue);
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  display: inline-block;
  margin-bottom: 0.75rem;
}

.demand-type-title {
  font-size: 1.2rem;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.demand-type-desc {
  font-size: 0.925rem;
  color: var(--text-body);
  margin-bottom: 1rem;
  line-height: 1.65;
}

.demand-type-focus {
  font-size: 0.85rem;
  color: var(--text-secondary);
  border-top: 1px dashed var(--border);
  padding-top: 0.75rem;
}

/* Section 02: Traffic Scale UI */
.traffic-scale-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin-top: 2rem;
}

.traffic-tier-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative;
}

.traffic-amount {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--navy-deep);
  line-height: 1.1;
  margin-bottom: 0.35rem;
}

.traffic-level {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--amber);
  margin-bottom: 0.75rem;
  display: block;
}

.traffic-guide-line {
  height: 2px;
  background-color: var(--guide-line);
  margin: 0.75rem 0 1rem 0;
}

.traffic-factors {
  margin-top: 2rem;
  background: var(--surface-soft);
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.traffic-factors h4 {
  font-size: 1rem;
  color: var(--navy-deep);
  margin-bottom: 0.5rem;
}

.traffic-factors ul {
  padding-left: 1.25rem;
  font-size: 0.925rem;
  color: var(--text-body);
}

/* Section 03: Region Directory UI */
.region-dir-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-top: 2rem;
}

.region-item-row {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: grid;
  grid-template-columns: 160px 1fr 1fr;
  gap: 1.5rem;
  align-items: start;
}

.region-name-box {
  display: flex;
  flex-direction: column;
}

.region-name {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--navy-deep);
  line-height: 1.2;
}

.region-code {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 600;
  text-transform: uppercase;
}

.region-detail-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--slate-blue);
  margin-bottom: 0.35rem;
}

.region-notice {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Section 04: Line Knowledge Table UI */
.line-table-wrapper {
  overflow-x: auto;
  margin-top: 2rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.line-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}

.line-table th {
  background-color: var(--light-fog-blue);
  color: var(--navy-deep);
  font-weight: 700;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
}

.line-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-body);
}

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

.line-type-name {
  font-weight: 700;
  color: var(--navy-deep);
}

.line-qa-box {
  margin-top: 1.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.line-qa-card {
  background: var(--surface-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}

.line-qa-card h4 {
  font-size: 0.95rem;
  color: var(--navy-deep);
  margin-bottom: 0.4rem;
}

.line-qa-card p {
  font-size: 0.9rem;
}

/* Section 05: AI vs Video Demand UI */
.use-case-comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

.use-case-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.75rem;
}

.use-case-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.use-case-title {
  font-size: 1.3rem;
  color: var(--navy-deep);
}

.use-case-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1rem;
}

.use-case-tag {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--navy-deep);
  background: var(--fog-blue);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
}

/* Section 06: Device Index UI */
.device-index-table {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 2rem;
}

.device-row {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  display: grid;
  grid-template-columns: 130px 1fr 1fr 1fr;
  gap: 1.25rem;
  align-items: start;
}

.device-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--navy-deep);
}

.device-col-title {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--slate-blue);
  margin-bottom: 0.25rem;
  text-transform: uppercase;
}

/* Section 07: Pricing - Coordinate Pricing (坐标价目) */
.coordinate-pricing {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 2rem;
}

.pricing-row-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.75rem;
  display: grid;
  grid-template-columns: 140px 1.5fr 1fr 180px;
  gap: 1.5rem;
  align-items: center;
  position: relative;
  transition: border-color var(--transition-fast);
}

.pricing-row-item:hover {
  border-color: var(--slate-blue);
}

.pricing-row-featured {
  background-color: var(--light-fog-blue);
  border-left: 4px solid var(--navy-deep);
  box-shadow: var(--shadow-subtle);
}

.pricing-level-badge {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--slate-blue);
}

.pricing-featured-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: #FFFFFF;
  background: var(--amber);
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  margin-left: 0.5rem;
}

.pricing-name-group {
  display: flex;
  flex-direction: column;
}

.pricing-plan-name {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
}

.pricing-plan-data {
  font-size: 0.9rem;
  color: var(--navy-deep);
  font-weight: 600;
}

.pricing-price-group {
  display: flex;
  flex-direction: column;
}

.pricing-amount {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--navy-deep);
  line-height: 1.1;
}

.pricing-row-featured .pricing-amount {
  font-size: 2.2rem;
  color: var(--navy-deep-2);
}

.pricing-cycle {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.pricing-action {
  text-align: right;
}

.pricing-note-disclaimer {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 1.25rem;
  text-align: center;
  font-style: italic;
}

/* Section 08: Xingwei Review Section */
.review-summary-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 2rem;
  display: grid;
  grid-template-columns: 240px 1fr 200px;
  gap: 2rem;
  align-items: center;
  margin-top: 2rem;
}

.review-summary-left h4 {
  font-size: 1.1rem;
  color: var(--navy-deep);
  margin-bottom: 0.5rem;
}

.review-checklist {
  list-style: none;
  font-size: 0.9rem;
  color: var(--text-body);
}

.review-checklist li {
  margin-bottom: 0.35rem;
  position: relative;
  padding-left: 1.1rem;
}

.review-checklist li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--amber);
  font-weight: bold;
}

/* Section 09: Troubleshooting Matrix (问题定位矩阵) */
.trouble-matrix {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 2rem;
}

.trouble-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.symptom-tag {
  font-size: 0.8rem;
  font-weight: 700;
  color: #FFFFFF;
  background-color: var(--navy-deep);
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  display: inline-block;
  margin-bottom: 0.75rem;
}

.symptom-title {
  font-size: 1.15rem;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.symptom-priority {
  font-size: 0.9rem;
  color: var(--text-body);
  line-height: 1.65;
}

.dns-notice-box {
  margin-top: 1.75rem;
  background: var(--surface-soft);
  padding: 1.1rem 1.35rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  font-size: 0.925rem;
}

/* Section 10: Articles Center - Question Index UI */
.articles-index {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 2rem;
}

.featured-article-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--amber);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: grid;
  grid-template-columns: 1fr 220px;
  gap: 1.5rem;
  align-items: center;
  margin-bottom: 1rem;
}

.article-list-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.1rem 1.5rem;
  display: grid;
  grid-template-columns: 120px 1fr 1.2fr 120px;
  gap: 1.25rem;
  align-items: center;
}

.article-cat-badge {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--slate-blue);
  background: var(--fog-blue);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  text-align: center;
}

.article-title-link {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.4;
}

.article-direct-answer {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Section 11: FAQ UI - Question Index + Expand */
.faq-filter-tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}

.faq-tab-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--text-body);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.faq-tab-btn:hover, .faq-tab-btn.active {
  background: var(--navy-deep);
  color: #FFFFFF;
  border-color: var(--navy-deep);
}

.faq-accordion {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--border);
}

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

.faq-question-btn {
  width: 100%;
  background: none;
  border: none;
  padding: 1.2rem 0;
  text-align: left;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.faq-question-btn:hover {
  color: var(--navy-deep);
}

.faq-icon {
  font-size: 1.25rem;
  font-weight: 300;
  color: var(--slate-blue);
  transition: transform var(--transition-fast);
}

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

.faq-answer {
  display: none;
  padding: 0 0 1.25rem 0;
  font-size: 0.95rem;
  color: var(--text-body);
  line-height: 1.8;
}

.faq-item.is-open .faq-answer {
  display: block;
}

/* Footer UI */
.site-footer {
  background-color: var(--fog-blue);
  border-top: 1px solid var(--border);
  padding: 3rem 0 2rem 0;
  color: var(--navy-deep);
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.8fr 1fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

.footer-brand-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--navy-deep);
  margin-bottom: 0.35rem;
}

.footer-brand-sub {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.footer-col-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--navy-deep);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.9rem;
}

.footer-links a {
  color: var(--text-body);
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.friend-links {
  display: flex;
  gap: 1.25rem;
  align-items: center;
}

.friend-links a {
  color: var(--text-body);
}

/* Article Page Specific Layout */
.article-container {
  max-width: 820px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.article-meta {
  display: flex;
  gap: 1.25rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.75rem;
  flex-wrap: wrap;
}

.quick-conclusion-box {
  background-color: var(--surface-soft);
  border-left: 4px solid var(--amber);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0 2rem 0;
}

.quick-conclusion-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--navy-deep);
  margin-bottom: 0.4rem;
}

.article-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  line-height: 1.85;
}

.article-content h2 {
  margin: 2rem 0 1rem 0;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);

}

.article-content h3 {
  margin: 1.5rem 0 0.75rem 0;
}

.article-content p {
  margin-bottom: 1.25rem;
}

.article-content ul, .article-content ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

.article-content li {
  margin-bottom: 0.35rem;
}

.related-reads-box {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

/* Category Page Specific Layout */
.cat-hero {
  background: var(--surface-soft);
  padding: 3rem 0;
  border-bottom: 1px solid var(--border);
}

/* Media Queries for Responsive Design */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 200px 1fr 200px;
  }
  .region-item-row {
    grid-template-columns: 140px 1fr 1fr;
  }
  .device-row {
    grid-template-columns: 110px 1fr 1fr 1fr;
  }
  .pricing-row-item {
    grid-template-columns: 120px 1.2fr 1fr 150px;
  }
  .footer-grid {
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
  }
  .article-list-item {
    grid-template-columns: 100px 1fr 1.2fr 100px;
  }
}

@media (max-width: 768px) {
  .desktop-nav {
    display: none;
  }
  .mobile-menu-btn {
    display: block;
  }
  
  /* Mobile Hero transforms into vertical decision list */
  .hero-grid {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    min-height: auto;
  }
  .hero-ref-line-h, .hero-ref-line-v {
    display: none;
  }
  .hero-center {
    order: 1;
    padding: 1rem 0;
  }
  .hero-dir-top { order: 2; }
  .hero-dir-right { order: 3; }
  .hero-dir-left { order: 4; }
  .hero-dir-bottom { order: 5; }

  .region-item-row {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

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

  .device-row {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .pricing-row-item {
    grid-template-columns: 1fr;
    gap: 0.75rem;
    text-align: left;
  }

  .pricing-action {
    text-align: left;
  }

  .review-summary-box {
    grid-template-columns: 1fr;
  }

  .article-list-item {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }

  .featured-article-card {
    grid-template-columns: 1fr;
  }

  .line-qa-box {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
  .article-content {
    padding: 1.5rem;
  }
}

/* Prefers Reduced Motion */
@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;
  }
}