/* ==========================================================================
   69云 (69yun.lol) - Core Stylesheet (BEM Naming Architecture)
   Layer 1.5: Mediterranean Coastal Conversion UI
   Palette: #F8F5ED | #244B59 | #D17C57 | #D6B85A | #FFFFFF | #AFC8C5
   System Font Stack Only | Mobile-First | High Contrast Accessibility
   ========================================================================== */

:root {
  --color-bg: #F8F5ED;
  --color-surface: #FFFFFF;
  --color-surface-alt: #F1EDE2;
  --color-coastal-tint: #EAF1F0;
  --color-primary: #244B59;
  --color-primary-deep: #183540;
  --color-secondary: #D17C57;
  --color-secondary-hover: #B86542;
  --color-accent: #D6B85A;
  --color-supporting: #AFC8C5;
  --color-text: #18333D;
  --color-text-secondary: #244B59;
  --color-text-muted: #4A6873;
  --color-border: #AFC8C5;
  --color-border-light: #DCE7E5;
  --font-serif: "Songti SC", "STSong", "Noto Serif SC", "SimSun", Georgia, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  --max-width: 1160px;
  --header-height: 72px;
  --radius-soft: 12px;
  --radius-btn: 8px;
  --shadow-card: 0 10px 28px -8px rgba(36, 75, 89, 0.08);
  --shadow-hover: 0 16px 34px -10px rgba(36, 75, 89, 0.15);
}

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background-color: var(--color-bg);
  color: var(--color-text);
}

main {
  flex: 1;
}

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

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

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

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--color-secondary);
  outline-offset: 2px;
}

ul,
ol {
  list-style-position: inside;
}

/* ==========================================================================
   Layout Container & Sunlit Coastal Color Blocks
   ========================================================================== */

.layout-container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.section-block {
  padding: 4.5rem 0;
  border-bottom: 1px solid var(--color-border-light);
}

.section-block--alt {
  background-color: var(--color-surface);
}

.section-block--highlight {
  background: linear-gradient(180deg, #F8F5ED 0%, #EAF1F0 100%);
}

.section-header {
  max-width: 720px;
  margin-bottom: 2.75rem;
}

.section-header__title {
  font-family: var(--font-serif);
  font-size: clamp(1.625rem, 3.2vw, 2.25rem);
  font-weight: 700;
  line-height: 1.32;
  color: var(--color-primary);
  letter-spacing: 0.01em;
  margin-bottom: 0.875rem;
}

.section-header__desc {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   Header & Navigation (Whitewashed Glass Surface)
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background-color: rgba(248, 245, 237, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-supporting);
}

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

.site-header__logo {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  font-family: var(--font-serif);
  font-size: 1.3125rem;
  font-weight: 700;
  color: var(--color-primary);
  min-height: 44px;
  padding: 0.25rem 0;
}

.site-header__logo:hover {
  color: var(--color-secondary);
}

.site-header__logo-mark {
  width: 34px;
  height: 34px;
  flex-shrink: 0;
}

.site-header__toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 0.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-btn);
  color: var(--color-primary);
  cursor: pointer;
}

.site-header__nav {
  display: none;
  position: absolute;
  top: var(--header-height);
  left: 0;
  right: 0;
  background-color: var(--color-surface);
  border-bottom: 2px solid var(--color-supporting);
  padding: 1rem 1.25rem 1.5rem;
  box-shadow: var(--shadow-hover);
}

.site-header__nav--open {
  display: block;
}

.site-header__nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.site-header__nav-link {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0.5rem 0.875rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-primary);
  border-radius: var(--radius-btn);
}

.site-header__nav-link:hover,
.site-header__nav-link--active {
  color: var(--color-primary-deep);
  background-color: var(--color-coastal-tint);
}

.site-header__nav-cta {
  margin-top: 0.5rem;
}

/* ==========================================================================
   Buttons (Coastal Tone Transitions, >= 44px Touch Targets)
   ========================================================================== */

.btn-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.75rem 1.625rem;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  border-radius: var(--radius-btn);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-action--primary {
  background-color: var(--color-primary);
  color: #FFFFFF;
  border-color: var(--color-primary);
  box-shadow: 0 4px 12px rgba(36, 75, 89, 0.18);
}

.btn-action--primary:hover {
  background-color: var(--color-primary-deep);
  border-color: var(--color-primary-deep);
  color: #FFFFFF;
  transform: translateY(-1px);
}

.btn-action--secondary {
  background-color: var(--color-surface);
  color: var(--color-primary);
  border-color: var(--color-supporting);
}

.btn-action--secondary:hover {
  background-color: var(--color-coastal-tint);
  color: var(--color-primary-deep);
  border-color: var(--color-primary);
}

.btn-action--small {
  min-height: 44px;
  padding: 0.5rem 1.25rem;
  font-size: 0.9375rem;
}

.btn-action--full {
  width: 100%;
}

/* ==========================================================================
   Hero Section (Sunlit Coastal Architecture + Network Routing Visual)
   ========================================================================== */

.hero-panel {
  padding: 3.25rem 0 4.25rem;
  background: linear-gradient(135deg, #FFFFFF 0%, #F8F5ED 60%, #EAF1F0 100%);
  border-bottom: 1px solid var(--color-supporting);
}

.hero-panel__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.75rem;
  align-items: center;
}

.hero-panel__status-bar {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.375rem 0.875rem;
  background-color: #FFF9EB;
  border: 1px solid var(--color-accent);
  color: var(--color-primary-deep);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 999px;
  margin-bottom: 1.25rem;
}

.hero-panel__status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-secondary);
}

.hero-panel__title {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4.2vw, 2.95rem);
  font-weight: 700;
  line-height: 1.24;
  color: var(--color-primary);
  letter-spacing: -0.01em;
  margin-bottom: 1.125rem;
}

.hero-panel__subtitle {
  font-size: clamp(1.0625rem, 2vw, 1.21875rem);
  color: var(--color-text-secondary);
  line-height: 1.68;
  margin-bottom: 2rem;
  max-width: 600px;
}

.hero-panel__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.25rem;
}

.hero-panel__trust {
  border-top: 1px solid var(--color-border-light);
  padding-top: 1.375rem;
}

.hero-panel__trust-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-bottom: 0.625rem;
}

.hero-panel__trust-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.625rem 1.375rem;
  font-size: 0.9375rem;
  color: var(--color-primary);
}

.hero-panel__trust-item {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-weight: 600;
}

.hero-panel__visual {
  background-color: var(--color-surface);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-soft);
  padding: 1.375rem;
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.hero-panel__visual svg {
  transition: transform 0.35s ease;
}

.hero-panel__visual:hover svg {
  transform: scale(1.015);
}

.hero-panel__diagram-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 0.875rem;
  margin-bottom: 0.875rem;
  border-bottom: 1px solid var(--color-border-light);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-primary);
}

/* ==========================================================================
   Features Module (Open Coastal Cards with Soft Corners & Hover Lift)
   ========================================================================== */

.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

.feature-card {
  background-color: var(--color-surface);
  padding: 1.875rem;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-soft);
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--color-supporting);
}

.feature-card__icon-wrap {
  width: 48px;
  height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-coastal-tint);
  color: var(--color-primary);
  border: 1px solid var(--color-supporting);
  border-radius: 10px;
}

.feature-card__title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
}

.feature-card__desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   Usage Scenarios Module (4 Audience-Specific Coastal Cards)
   ========================================================================== */

.scenario-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

.scenario-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-soft);
  padding: 1.75rem;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
  transition: transform 0.22s ease, box-shadow 0.22s ease;
}

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

.scenario-card__meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding-bottom: 0.875rem;
  border-bottom: 1px solid var(--color-border-light);
}

.scenario-card__device {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-primary-deep);
  background-color: #FFF9EB;
  border: 1px solid var(--color-accent);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
}

.scenario-card__audience {
  font-size: 0.8125rem;
  color: var(--color-secondary);
  font-weight: 700;
}

.scenario-card__title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
}

.scenario-card__desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   Streaming & AI Compatibility Matrix
   ========================================================================== */

.matrix-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

.matrix-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-soft);
  padding: 1.375rem 1.5rem;
  box-shadow: var(--shadow-card);
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.matrix-item:hover {
  transform: translateY(-3px);
  border-color: var(--color-supporting);
}

.matrix-item__icon {
  width: 38px;
  height: 38px;
  flex-shrink: 0;
  color: var(--color-secondary);
  margin-top: 0.125rem;
}

.matrix-item__body {
  flex: 1;
}

.matrix-item__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.375rem;
}

.matrix-item__name {
  font-family: var(--font-serif);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-primary);
}

.matrix-item__badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.15rem 0.625rem;
  background-color: var(--color-coastal-tint);
  color: var(--color-primary-deep);
  border: 1px solid var(--color-supporting);
  border-radius: 999px;
}

.matrix-item__desc {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
}

.section-note {
  margin-top: 1.5rem;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Benefits Architecture Section
   ========================================================================== */

.benefit-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.375rem;
}

.benefit-row {
  background-color: var(--color-surface);
  border: 1px solid var(--color-supporting);
  border-left: 5px solid var(--color-secondary);
  border-radius: var(--radius-soft);
  padding: 1.75rem;
  box-shadow: var(--shadow-card);
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
}

.benefit-row__title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
}

.benefit-row__desc {
  font-size: 0.96875rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   Pricing Module (3 Tiers: Student / Office Recommended / Business)
   ========================================================================== */

.pricing-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem;
  align-items: stretch;
}

.plan-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-soft);
  padding: 2.25rem 1.875rem;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

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

.plan-card--featured {
  border: 2px solid var(--color-secondary);
  background-color: #FFFFFF;
  box-shadow: 0 14px 36px -8px rgba(209, 124, 87, 0.2);
}

.plan-card__ribbon {
  display: inline-block;
  align-self: flex-start;
  background-color: var(--color-secondary);
  color: #FFFFFF;
  font-size: 0.8125rem;
  font-weight: 700;
  padding: 0.3rem 0.75rem;
  margin-bottom: 0.875rem;
  border-radius: 999px;
}

.plan-card__name {
  font-family: var(--font-serif);
  font-size: 1.4375rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 0.35rem;
}

.plan-card__audience {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: 1.375rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--color-border-light);
}

.plan-card__price {
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
  margin-bottom: 1.625rem;
}

.plan-card__amount {
  font-family: var(--font-serif);
  font-size: 2.375rem;
  font-weight: 700;
  color: var(--color-primary-deep);
  line-height: 1;
}

.plan-card__period {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  font-weight: 600;
}

.plan-card__features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.8125rem;
  margin-bottom: 2rem;
}

.plan-card__feature-item {
  display: flex;
  align-items: flex-start;
  gap: 0.625rem;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.55;
}

.plan-card__check {
  width: 18px;
  height: 18px;
  color: var(--color-secondary);
  flex-shrink: 0;
  margin-top: 0.2rem;
}

/* ==========================================================================
   FAQ Accordion Module
   ========================================================================== */

.faq-list {
  max-width: 840px;
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.faq-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-soft);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.faq-item__summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 56px;
  padding: 1.125rem 1.375rem;
  font-family: var(--font-serif);
  font-size: 1.09375rem;
  font-weight: 700;
  color: var(--color-primary);
  cursor: pointer;
}

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

.faq-item__icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--color-secondary);
  transition: transform 0.2s ease;
}

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

.faq-item__answer {
  padding: 1rem 1.375rem 1.375rem;
  font-size: 0.96875rem;
  color: var(--color-text-secondary);
  line-height: 1.75;
  border-top: 1px solid var(--color-border-light);
}

/* ==========================================================================
   Final CTA Banner (Deep Mediterranean Sea-Slate + Warm Terracotta Highlight)
   ========================================================================== */

.final-cta {
  padding: 4.5rem 0;
  background: linear-gradient(135deg, #244B59 0%, #183540 100%);
  color: #FFFFFF;
}

.final-cta__box {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.875rem;
}

.final-cta__title {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3vw, 2.125rem);
  font-weight: 700;
  line-height: 1.32;
  color: #FFFFFF;
  margin-bottom: 0.625rem;
}

.final-cta__desc {
  font-size: 1.0625rem;
  color: #EAF1F0;
  max-width: 640px;
}

.final-cta .btn-action--primary {
  background-color: var(--color-secondary);
  border-color: var(--color-secondary);
  color: #FFFFFF;
}

.final-cta .btn-action--primary:hover {
  background-color: var(--color-secondary-hover);
  border-color: var(--color-secondary-hover);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-supporting);
  padding: 2.75rem 0 3.25rem;
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

.site-footer__inner {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.site-footer__top {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  justify-content: space-between;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-border-light);
}

.site-footer__brand {
  font-family: var(--font-serif);
  font-weight: 700;
  color: var(--color-primary);
  font-size: 1.1875rem;
}

.site-footer__nav {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.375rem;
}

.site-footer__link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--color-primary);
  font-weight: 600;
}

.site-footer__link:hover {
  color: var(--color-secondary);
}

.site-footer__bottom {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.875rem;
}

/* ==========================================================================
   Guides Hub & Article Pages
   ========================================================================== */

.breadcrumb-nav {
  padding: 1rem 0;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border-light);
  font-size: 0.875rem;
}

.breadcrumb-nav__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  color: var(--color-text-muted);
}

.breadcrumb-nav__link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--color-primary);
  font-weight: 600;
}

.guide-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem;
}

.guide-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-soft);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.22s ease, box-shadow 0.22s ease;
}

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

.guide-card__thumb {
  width: 100%;
  height: auto;
  display: block;
  background-color: var(--color-surface-alt);
  border-bottom: 1px solid var(--color-border-light);
  transition: transform 0.3s ease;
}

.guide-card:hover .guide-card__thumb {
  transform: scale(1.02);
}

.guide-card__content {
  padding: 1.625rem;
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: 0.75rem;
}

.guide-card__meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.guide-card__title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.38;
}

.guide-card__title-link {
  color: var(--color-primary);
}

.guide-card__title-link:hover {
  color: var(--color-secondary);
}

.guide-card__excerpt {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.68;
  flex: 1;
}

.guide-card__footer {
  padding-top: 0.75rem;
  border-top: 1px solid var(--color-border-light);
}

.guide-card__read-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-weight: 700;
  font-size: 0.9375rem;
  color: var(--color-secondary);
}

/* ==========================================================================
   Article & Legal Document Typography
   ========================================================================== */

.article-shell {
  padding: 2.75rem 0 4.5rem;
}

.article-shell__container {
  max-width: 820px;
  margin: 0 auto;
  background-color: var(--color-surface);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-soft);
  box-shadow: var(--shadow-card);
  padding: 2rem 1.375rem;
}

.article-header {
  padding-bottom: 1.5rem;
  margin-bottom: 1.875rem;
  border-bottom: 1px solid var(--color-border-light);
}

.article-header__title {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3.2vw, 2.1875rem);
  font-weight: 700;
  line-height: 1.32;
  color: var(--color-primary);
  margin-bottom: 0.875rem;
}

.article-header__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.article-body {
  font-size: 1.03125rem;
  line-height: 1.82;
  color: var(--color-text-secondary);
}

.article-body h2 {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-primary);
  margin: 2.25rem 0 0.875rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border-light);
}

.article-body h3 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-primary);
  margin: 1.5rem 0 0.625rem;
}

.article-body p {
  margin-bottom: 1.125rem;
}

.article-body ul,
.article-body ol {
  margin: 0 0 1.25rem 1.25rem;
  list-style-position: outside;
}

.article-body li {
  margin-bottom: 0.5rem;
}

.article-body a {
  color: var(--color-secondary-hover);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.article-table-wrap {
  width: 100%;
  overflow-x: auto;
  margin: 1.5rem 0;
}

.article-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.article-table th,
.article-table td {
  border: 1px solid var(--color-supporting);
  padding: 0.75rem;
  text-align: left;
}

.article-table th {
  background-color: var(--color-surface-alt);
  color: var(--color-primary);
  font-weight: 700;
}

.article-callout {
  background-color: #FFF9EB;
  border-left: 4px solid var(--color-secondary);
  border-radius: 6px;
  padding: 1.125rem 1.25rem;
  margin: 1.5rem 0;
}

.article-cta-box {
  margin-top: 2.5rem;
  padding: 1.875rem;
  background: linear-gradient(135deg, #F8F5ED 0%, #EAF1F0 100%);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-soft);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: flex-start;
}

.article-cta-box__title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
}

.article-cta-box__desc {
  font-size: 0.96875rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.25rem;
}

.article-related {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-border-light);
}

.article-related__title {
  font-family: var(--font-serif);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 0.875rem;
}

.article-related__list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.625rem;
}

.article-related__link {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0.625rem 0.875rem;
  background-color: var(--color-bg);
  border: 1px solid var(--color-supporting);
  border-radius: var(--radius-btn);
  color: var(--color-primary);
  font-weight: 600;
  text-decoration: none !important;
}

.article-related__link:hover {
  border-color: var(--color-secondary);
  color: var(--color-secondary-hover);
}

/* ==========================================================================
   Mobile Sticky Bottom CTA (Hidden on Desktop, Hidden over Footer)
   ========================================================================== */

.sticky-cta {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 90;
  background-color: rgba(255, 255, 255, 0.96);
  border-top: 1px solid var(--color-supporting);
  padding: 0.625rem 1rem;
  box-shadow: 0 -4px 16px rgba(36, 75, 89, 0.12);
  transform: translateY(100%);
  transition: transform 0.2s ease;
  pointer-events: none;
}

.sticky-cta--visible {
  transform: translateY(0);
  pointer-events: auto;
}

.sticky-cta__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.sticky-cta__text {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-primary);
}

/* ==========================================================================
   Responsive Breakpoints (Tablet >= 768px, Desktop >= 1024px)
   ========================================================================== */

@media (min-width: 768px) {
  .site-header__toggle {
    display: none;
  }

  .site-header__nav {
    display: flex;
    position: static;
    background: transparent;
    border: none;
    padding: 0;
    box-shadow: none;
    align-items: center;
    gap: 1.5rem;
  }

  .site-header__nav-list {
    flex-direction: row;
    align-items: center;
    gap: 0.25rem;
  }

  .site-header__nav-cta {
    margin-top: 0;
  }

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

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

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

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

  .final-cta__box {
    flex-direction: row;
    align-items: center;
  }

  .site-footer__top {
    flex-direction: row;
    align-items: center;
  }

  .article-shell__container {
    padding: 2.75rem 3.25rem;
  }

  .sticky-cta {
    display: none;
  }
}

@media (min-width: 1024px) {
  .hero-panel {
    padding: 4.25rem 0 5rem;
  }

  .hero-panel__grid {
    grid-template-columns: 1.08fr 0.92fr;
    gap: 3.5rem;
  }

  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .matrix-grid {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .guide-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}