/* ==========================================================================
   STYLE: Mauve Product Catalog Design System
   Brand: TAG 机场 (TAG Transit Catalog)
   Color Palette:
     - Pure White:       #FFFFFF (Card surfaces, clean catalog plates)
     - Deep Plum-Gray:   #4D4250 (Primary ink, strong borders, dark text)
     - Muted Mauve:      #B798AE (Primary catalog accent, badges, buttons)
     - Pale Ivory:       #F6F1F3 (Canvas fill, soft contrast blocks, borders)
   Supporting Tonal Values:
     - Plum Dark:        #372E3A (Headings, deepest contrast)
     - Plum Muted:       #6E6272 (Body secondary, metadata, captions)
     - Mauve Dark:       #8E6283 (Accessible CTA button text & focused links, WCAG AA/AAA)
     - Mauve Light:      rgba(183, 152, 174, 0.16) (Subtle tag fills)
     - Mauve Subtle:     rgba(183, 152, 174, 0.08)
     - Ivory Subtle:     #FAF7F8
     - Border Default:   rgba(77, 66, 80, 0.16)
     - Border Strong:    #4D4250
   Typography:
     - Display Headings: Chinese serif fallback ("Songti SC", "Source Han Serif SC", "Noto Serif SC", STSong, "SimSun", Georgia, serif)
     - Body Text:        Clean humanist sans-serif (-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif)
     - Sizes:            H1 55px desktop / 35px mobile; Body 17px
   Aesthetic:
     - Mauve product catalog, editorial index margins, subtle page-line reveals.
     - Strictly no neon, no glossy gradients. Support prefers-reduced-motion.
   ========================================================================== */

:root {
  --color-white: #FFFFFF;
  --color-plum: #4D4250;
  --color-plum-dark: #372E3A;
  --color-plum-muted: #6E6272;
  --color-plum-light: rgba(77, 66, 80, 0.06);
  --color-mauve: #B798AE;
  --color-mauve-dark: #8E6283;
  --color-mauve-light: rgba(183, 152, 174, 0.16);
  --color-mauve-subtle: rgba(183, 152, 174, 0.08);
  --color-ivory: #F6F1F3;
  --color-ivory-subtle: #FAF7F8;
  --color-border: rgba(77, 66, 80, 0.16);
  --color-border-strong: #4D4250;

  /* Aliases for compatibility */
  --color-charcoal: var(--color-plum);
  --color-charcoal-muted: var(--color-plum-muted);
  --color-aged-copper: var(--color-mauve-dark);
  --color-copper-dark: var(--color-plum-dark);

  --font-heading: "Songti SC", "Source Han Serif SC", "Noto Serif CJK SC", "Noto Serif SC", STSong, "SimSun", Georgia, "Times New Roman", serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: "SF Mono", Consolas, "Liberation Mono", Menlo, Courier, monospace;

  --body-size: 17px;
  --container-max: 1220px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: var(--body-size);
  font-weight: 400;
  line-height: 1.75;
  color: var(--color-plum);
  background-color: var(--color-white);
  overflow-x: hidden;
  overflow-wrap: anywhere;
}

/* Gentle Page-Line Reveals */
.catalog-divider-line {
  height: 1px;
  width: 100%;
  background-color: var(--color-border);
  position: relative;
  overflow: hidden;
  margin: 0;
}

.catalog-divider-line::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 120px;
  background-color: var(--color-mauve);
  animation: lineScan 8s ease-in-out infinite alternate;
}

@keyframes lineScan {
  0% { transform: translateX(0); opacity: 0.3; }
  50% { opacity: 0.9; }
  100% { transform: translateX(calc(100vw - 120px)); opacity: 0.3; }
}

/* Typography Hierarchy */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--color-plum-dark);
  line-height: 1.3;
  margin-bottom: 0.75rem;
}

h1 {
  font-size: clamp(35px, 4.6vw, 55px);
  letter-spacing: -0.5px;
}

@media (min-width: 1024px) {
  h1 {
    font-size: 55px;
  }
}

@media (max-width: 768px) {
  h1 {
    font-size: 35px;
  }
}

h2 {
  font-size: clamp(26px, 3.2vw, 36px);
  letter-spacing: -0.3px;
}

h3 {
  font-size: clamp(20px, 2.3vw, 24px);
}

p {
  margin-bottom: 1.25rem;
  color: var(--color-plum);
}

p.lead {
  font-size: 1.125rem;
  color: var(--color-plum-muted);
  line-height: 1.85;
}

a {
  color: var(--color-mauve-dark);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

a:hover {
  color: var(--color-plum-dark);
}

code, pre, .font-mono {
  font-family: var(--font-mono);
}

pre {
  max-width: 100%;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
  background-color: var(--color-ivory);
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  font-size: 14px;
  line-height: 1.6;
}

code {
  font-size: 0.88em;
  background-color: var(--color-ivory);
  padding: 2px 6px;
  border-radius: 3px;
  border: 1px solid var(--color-border);
}

pre code {
  padding: 0;
  border: none;
  background: transparent;
  font-size: inherit;
}

table {
  width: 100%;
  max-width: 100%;
  border-collapse: collapse;
}

.table-responsive {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

img, svg {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Container & Sections */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.section {
  padding-top: 84px;
  padding-bottom: 84px;
  position: relative;
}

.section-contrast {
  background-color: var(--color-ivory-subtle);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-catalog {
  background-color: var(--color-ivory);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.section-header {
  text-align: center;
  max-width: 820px;
  margin: 0 auto 54px auto;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--color-mauve-dark);
  background-color: var(--color-mauve-light);
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  margin-bottom: 14px;
  border: 1px solid rgba(142, 98, 131, 0.2);
}

.spec-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 600;
  color: var(--color-plum);
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  padding: 3px 10px;
  border-radius: var(--radius-sm);
}

.spec-badge.mauve,
.spec-badge.copper {
  color: var(--color-mauve-dark);
  background-color: var(--color-mauve-light);
  border-color: rgba(142, 98, 131, 0.3);
}

/* Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-align: center;
  line-height: 1.4;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--color-plum-dark);
  color: #FFFFFF;
  border-color: var(--color-plum-dark);
}

.btn-primary:hover {
  background-color: var(--color-mauve-dark);
  border-color: var(--color-mauve-dark);
  color: #FFFFFF;
}

.btn-secondary {
  background-color: var(--color-ivory);
  color: var(--color-plum-dark);
  border-color: var(--color-border);
}

.btn-secondary:hover {
  background-color: #FFFFFF;
  border-color: var(--color-mauve);
  color: var(--color-mauve-dark);
}

.btn-sm {
  font-size: 13.5px;
  padding: 8px 16px;
}

.btn-block {
  display: flex;
  width: 100%;
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-plum-dark);
  text-decoration: none;
}

.brand-logo:hover {
  color: var(--color-mauve-dark);
}

.brand-symbol {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-ivory);
  border: 1px solid var(--color-mauve);
  border-radius: var(--radius-sm);
}

.nav-desktop {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-plum);
  padding: 6px 0;
  position: relative;
}

.nav-link:hover {
  color: var(--color-mauve-dark);
}

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

/* Mobile Toggle */
.mobile-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 36px;
  height: 36px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 8px;
  cursor: pointer;
}

.mobile-toggle span {
  width: 100%;
  height: 2px;
  background-color: var(--color-plum);
  transition: all 0.25s ease;
}

.mobile-toggle.is-active span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}
.mobile-toggle.is-active span:nth-child(2) {
  opacity: 0;
}
.mobile-toggle.is-active span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.mobile-nav {
  display: none;
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  padding: 20px 24px;
}

.mobile-nav.is-open {
  display: block;
}

.mobile-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 20px;
}

.mobile-nav-link {
  display: block;
  font-size: 16px;
  font-weight: 500;
  color: var(--color-plum);
  padding: 8px 0;
  border-bottom: 1px solid rgba(77, 66, 80, 0.08);
}

/* Hero Section: Left Copy / Right Region Catalog Dashboard */
.hero-section {
  padding-top: 64px;
  padding-bottom: 72px;
  background: linear-gradient(180deg, #FFFFFF 0%, var(--color-ivory-subtle) 100%);
  border-bottom: 1px solid var(--color-border);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.95fr;
  gap: 50px;
  align-items: center;
}

.hero-copy {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero-meta-strip {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.hero-badges-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 10px;
  font-size: 14px;
  color: var(--color-plum-muted);
}

.hero-badges-row span {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Mauve Catalog Dashboard (Right Visual) */
.catalog-dashboard-panel {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  box-shadow: 0 4px 18px rgba(77, 66, 80, 0.06);
  padding: 20px;
  position: relative;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 12px;
  margin-bottom: 16px;
}

.panel-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--color-plum);
  letter-spacing: 1px;
}

.indicator-dot {
  width: 8px;
  height: 8px;
  background-color: var(--color-mauve);
  border-radius: 50%;
  display: inline-block;
}

.panel-spec-id {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-plum-muted);
}

.catalog-svg-wrap {
  width: 100%;
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px;
  margin-bottom: 16px;
}

.panel-status-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 10px;
}

.panel-cell {
  text-align: center;
}

.panel-cell-label {
  font-family: var(--font-mono);
  font-size: 9.5px;
  color: var(--color-plum-muted);
  text-transform: uppercase;
}

.panel-cell-value {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--color-plum-dark);
  margin-top: 2px;
}

.panel-cell-value.mauve {
  color: var(--color-mauve-dark);
}

.panel-footer-note {
  font-size: 11.5px;
  color: var(--color-plum-muted);
  margin-top: 10px;
  line-height: 1.5;
  text-align: center;
}

/* ==========================================================================
   ADVANTAGES SECTION: Three Different Catalog Entry Formats
   ========================================================================== */
.catalog-entries-list {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

/* Catalog Entry Format 1: Technical Spec Sheet (Ledger & Schematic) */
.catalog-entry-spec {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  padding: 32px;
  box-shadow: 0 2px 12px rgba(77, 66, 80, 0.04);
}

.entry-header-strip {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 14px;
  margin-bottom: 24px;
}

.entry-format-tag {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  color: var(--color-mauve-dark);
  letter-spacing: 1.2px;
}

.entry-serial {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-plum-muted);
}

.entry-spec-grid {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 36px;
  align-items: center;
}

.entry-diagram-box {
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 20px;
}

/* Catalog Entry Format 2: Illustrated Regional Ledger (Radar Hub & Tab Matrix) */
.catalog-entry-ledger {
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px;
}

.entry-ledger-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 36px;
  align-items: center;
}

/* Catalog Entry Format 3: Protocol Blueprint Sheet (Flow steps & Badges) */
.catalog-entry-blueprint {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-left: 5px solid var(--color-mauve-dark);
  border-radius: var(--radius-md);
  padding: 32px;
  box-shadow: 0 2px 12px rgba(77, 66, 80, 0.04);
}

.entry-blueprint-grid {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 36px;
  align-items: center;
}

.catalog-param-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  margin-top: 18px;
}

.catalog-param-table th, .catalog-param-table td {
  padding: 8px 12px;
  border: 1px solid var(--color-border);
  text-align: left;
}

.catalog-param-table th {
  background-color: var(--color-ivory);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-plum-dark);
}

/* ==========================================================================
   NODES SECTION: Genuinely Functional Region Index
   ========================================================================== */
.node-index-controls {
  max-width: 860px;
  margin: 0 auto 36px auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.node-search-box {
  position: relative;
  width: 100%;
}

.node-search-input {
  width: 100%;
  padding: 14px 20px 14px 46px;
  font-family: var(--font-body);
  font-size: 16px;
  color: var(--color-plum);
  background-color: #FFFFFF;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.node-search-input:focus {
  border-color: var(--color-mauve-dark);
  box-shadow: 0 0 0 3px rgba(183, 152, 174, 0.25);
}

.node-search-icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-plum-muted);
  pointer-events: none;
}

.node-filter-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.filter-chip {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  color: var(--color-plum);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.filter-chip:hover {
  border-color: var(--color-mauve);
  color: var(--color-mauve-dark);
}

.filter-chip.active {
  background-color: var(--color-plum-dark);
  color: #FFFFFF;
  border-color: var(--color-plum-dark);
}

.region-strip-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.region-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 22px;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.region-card:hover {
  transform: translateY(-3px);
  border-color: var(--color-mauve);
  box-shadow: 0 6px 18px rgba(77, 66, 80, 0.08);
}

.region-card.hidden {
  display: none !important;
}

.region-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.region-flag-code {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--color-plum-dark);
  display: flex;
  align-items: center;
  gap: 6px;
}

.region-status-pill {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background-color: var(--color-mauve-light);
  color: var(--color-mauve-dark);
  font-weight: 600;
}

.region-name {
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-plum-dark);
  margin-bottom: 12px;
}

.region-specs-list {
  list-style: none;
  font-size: 13.5px;
  margin-top: 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-top: 1px dashed var(--color-border);
  padding-top: 14px;
}

.region-specs-list li {
  display: flex;
  justify-content: space-between;
}

.spec-k {
  color: var(--color-plum-muted);
}

.spec-v {
  font-weight: 600;
  color: var(--color-plum-dark);
}

.node-empty-state {
  display: none;
  text-align: center;
  padding: 40px;
  background-color: #FFFFFF;
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  margin-top: 20px;
  color: var(--color-plum-muted);
}

.node-empty-state.show {
  display: block;
}

/* ==========================================================================
   AI & STREAMING SCENARIOS: Separate Spreads
   ========================================================================== */
.scenario-block {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 36px;
  margin-bottom: 40px;
}

.scenario-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 18px;
  flex-wrap: wrap;
  gap: 16px;
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.app-card {
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 22px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.app-card:hover {
  background-color: #FFFFFF;
  border-color: var(--color-mauve);
}

.app-card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.app-card-name {
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-plum-dark);
}

.app-card-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-mauve-dark);
  background-color: var(--color-mauve-light);
  padding: 2px 6px;
  border-radius: 2px;
}

.app-card-desc {
  font-size: 14px;
  color: var(--color-plum-muted);
  line-height: 1.65;
  margin-bottom: 16px;
}

.app-card-specs {
  font-size: 12.5px;
  color: var(--color-plum-dark);
  font-weight: 600;
  border-top: 1px solid rgba(77, 66, 80, 0.1);
  padding-top: 10px;
}

/* ==========================================================================
   PRICING: Side-by-Side Catalog Comparison
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(77, 66, 80, 0.08);
}

/* Exactly One Recommended Package */
.pricing-card.recommended {
  border: 2px solid var(--color-mauve-dark);
  background-color: #FFFFFF;
  box-shadow: 0 6px 20px rgba(142, 98, 131, 0.15);
}

.recommend-tag {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--color-mauve-dark);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 12px;
  letter-spacing: 1px;
  white-space: nowrap;
}

.plan-head {
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 20px;
  margin-bottom: 20px;
}

.plan-name {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-plum-dark);
  margin-bottom: 6px;
}

.plan-desc {
  font-size: 13.5px;
  color: var(--color-plum-muted);
  line-height: 1.5;
  min-height: 40px;
}

.plan-price-box {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-top: 14px;
}

.plan-price-currency {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-plum-dark);
}

.plan-price-num {
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 700;
  color: var(--color-plum-dark);
  line-height: 1;
}

.plan-price-cycle {
  font-size: 13px;
  color: var(--color-plum-muted);
}

.plan-features {
  list-style: none;
  font-size: 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 28px;
}

.plan-features li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.plan-features svg {
  width: 16px;
  height: 16px;
  color: var(--color-mauve-dark);
  flex-shrink: 0;
  margin-top: 4px;
}

.pricing-disclosure {
  margin-top: 36px;
  padding: 16px 20px;
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--color-plum-muted);
  line-height: 1.7;
  text-align: center;
}

/* ==========================================================================
   ARTICLES SECTION: Reading Shelf (3 Desktop / 2 Tablet / 1 Mobile)
   ========================================================================== */
.articles-shelf-wrapper {
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 36px 32px;
}

.shelf-header-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 2px solid var(--color-plum-dark);
  padding-bottom: 12px;
  margin-bottom: 28px;
}

.shelf-title {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-plum-dark);
}

.shelf-index-indicator {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-mauve-dark);
  font-weight: 700;
}

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

.spec-article-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
  border-top: 3px solid var(--color-mauve);
}

.spec-article-card:hover {
  transform: translateY(-4px);
  border-top-color: var(--color-plum-dark);
  border-color: var(--color-mauve);
  box-shadow: 0 6px 18px rgba(77, 66, 80, 0.08);
}

.article-spec-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.article-spec-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-plum-muted);
  font-weight: 600;
}

.article-category {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-mauve-dark);
  background-color: var(--color-mauve-light);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.article-title {
  font-family: var(--font-heading);
  font-size: 17.5px;
  font-weight: 700;
  color: var(--color-plum-dark);
  line-height: 1.45;
  margin-bottom: 10px;
}

.article-excerpt {
  font-size: 14px;
  color: var(--color-plum-muted);
  line-height: 1.65;
  margin-bottom: 16px;
}

.article-spec-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--color-border);
  padding-top: 12px;
  font-size: 12.5px;
  color: var(--color-plum-muted);
}

.article-read-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-weight: 600;
  color: var(--color-mauve-dark);
}

/* ==========================================================================
   TESTIMONIALS SECTION
   ========================================================================== */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.testimonial-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.testimonial-header {
  margin-bottom: 14px;
}

.testimonial-author {
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-plum-dark);
}

.testimonial-role {
  font-size: 12px;
  color: var(--color-plum-muted);
}

.testimonial-text {
  font-size: 14px;
  color: var(--color-plum);
  line-height: 1.7;
  margin-bottom: 16px;
}

.testimonial-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-mauve-dark);
  background-color: var(--color-mauve-light);
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  align-self: flex-start;
}

/* ==========================================================================
   FAQ SECTION: Accessible Accordion
   ========================================================================== */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item[open] {
  border-color: var(--color-mauve);
}

.faq-summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 24px;
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 700;
  color: var(--color-plum-dark);
  cursor: pointer;
  user-select: none;
  list-style: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-icon {
  width: 18px;
  height: 18px;
  color: var(--color-mauve-dark);
  transition: transform 0.2s ease;
  flex-shrink: 0;
  margin-left: 12px;
}

.faq-item[open] .faq-icon {
  transform: rotate(180deg);
}

.faq-body {
  padding: 0 24px 20px 24px;
  font-size: 15px;
  color: var(--color-plum);
  line-height: 1.75;
}

/* ==========================================================================
   SITE FOOTER: Catalog Ledger Format & Partner Links
   ========================================================================== */
.site-footer {
  background-color: var(--color-ivory);
  border-top: 1px solid var(--color-border-strong);
  padding: 64px 0 36px 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.9fr 0.9fr 1.3fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-col h4 {
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-plum-dark);
  margin-bottom: 18px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 8px;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 14.5px;
  color: var(--color-plum);
}

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

.pbn-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.pbn-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-plum-dark);
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
}

.pbn-link:hover {
  background-color: var(--color-mauve-light);
  border-color: var(--color-mauve);
  color: var(--color-mauve-dark);
}

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
  color: var(--color-plum-muted);
}

/* ==========================================================================
   ARTICLE & SECONDARY PAGE INNER CONTENT STYLING
   ========================================================================== */
.breadcrumb-nav {
  margin-bottom: 24px;
}

.breadcrumb-list {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  font-size: 13.5px;
}

.breadcrumb-item a {
  color: var(--color-plum-muted);
}

.breadcrumb-item a:hover {
  color: var(--color-mauve-dark);
}

.breadcrumb-item.active {
  color: var(--color-plum-dark);
  font-weight: 600;
}

.breadcrumb-separator {
  color: var(--color-border-strong);
}

.article-header-wrap {
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 24px;
  margin-bottom: 36px;
}

.article-meta-row {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--color-plum-muted);
  margin-top: 14px;
}

.article-content {
  line-height: 1.85;
}

.article-content h2 {
  margin-top: 40px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 8px;
}

.article-content h3 {
  margin-top: 28px;
  margin-bottom: 14px;
}

.article-content ul, .article-content ol {
  margin-left: 24px;
  margin-bottom: 20px;
}

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

.article-content blockquote {
  border-left: 4px solid var(--color-mauve);
  background-color: var(--color-ivory);
  padding: 16px 20px;
  margin: 24px 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--color-plum);
}

.article-cta-box {
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-mauve-dark);
  border-radius: var(--radius-sm);
  padding: 28px;
  margin: 40px 0;
  text-align: center;
}

.related-articles-box {
  margin-top: 48px;
  padding-top: 28px;
  border-top: 1px solid var(--color-border);
}

.related-links-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 16px;
}

.related-link-card {
  background-color: #FFFFFF;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: all 0.2s ease;
}

.related-link-card:hover {
  border-color: var(--color-mauve);
  background-color: var(--color-ivory);
}

/* ==========================================================================
   RESPONSIVE MEDIA QUERIES (375, 390, 430, 768, 1024, 1440px)
   ========================================================================== */

/* Tablet & Smaller Desktops: <= 1024px */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .catalog-dashboard-panel {
    max-width: 680px;
    margin: 0 auto;
  }

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

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

  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

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

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

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

  .entry-spec-grid,
  .entry-ledger-grid,
  .entry-blueprint-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

/* Tablets & Mobile: <= 768px */
@media (max-width: 768px) {
  .section {
    padding-top: 56px;
    padding-bottom: 56px;
  }

  .nav-desktop {
    display: none;
  }

  .mobile-toggle {
    display: flex;
  }

  .region-strip-grid {
    grid-template-columns: 1fr;
  }

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

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

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

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

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

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

  .related-links-grid {
    grid-template-columns: 1fr;
  }
}

/* Mobile Screens: <= 430px */
@media (max-width: 430px) {
  .container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .btn {
    width: 100%;
  }

  .btn-group {
    flex-direction: column;
    width: 100%;
  }

  .plan-price-num {
    font-size: 34px;
  }

  .faq-summary {
    padding: 16px;
    font-size: 16px;
  }

  .faq-body {
    padding: 0 16px 16px 16px;
  }
}

/* Accessibility: Support 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;
  }

  .catalog-divider-line::after {
    animation: none !important;
  }
}