/* ==========================================================================
   蛙爪云 (Wazhuayun) - Set 2 Theme: 中缝对照系统 (Center Seam Comparison System)
   CSS Variables, Typography, Layout, Responsive Grid, Components & Subpages
   ========================================================================== */

:root {
  /* Main Brand Palette */
  --bg: #F6F1E8;             /* 主背景: 奶油米 */
  --paper: #FFFDFC;          /* 纸白 */
  --surface: #FFFFFF;        /* 纯白 */
  --text: #292724;           /* 主文字: 墨炭 */
  --body: #625D58;           /* 正文: 灰炭 */
  --muted: #91877F;          /* 次级: 浅暖灰 */
  --charcoal: #363632;       /* 炭黑 */
  --dark-charcoal: #292B28;  /* 深炭 */
  --brick: #94584F;          /* 砖红 (主强调) */
  --brick-dark: #72433D;     /* 深砖红 */
  --brick-soft: #F1E4E1;     /* 浅砖红 */
  --sage: #77806F;           /* 鼠尾草绿 */
  --sage-dark: #5C6556;      /* 深鼠尾草 */
  --sage-soft: #ECEFE9;      /* 浅鼠尾草 */
  --sand: #B28B64;           /* 暖沙 */
  --sand-dark: #8D6A4D;      /* 深暖沙 */
  --sand-soft: #F1E8DE;      /* 浅暖沙 */
  --border: #DDD4C8;         /* 边框 */
  --seam: #C9BCAE;           /* 中缝线 */

  /* Typography */
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --radius-sm: 4px;
  --radius-md: 6px;
  --header-height: 72px;
  --container-max: 1220px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-main);
  -webkit-font-smoothing: antialiased;
}

body {
  line-height: 1.8;
  color: var(--body);
  background-color: var(--bg);
  overflow-x: hidden;
}

/* Focus styles */
a:focus-visible, button:focus-visible, input:focus-visible {
  outline: 2px solid var(--brick);
  outline-offset: 3px;
}

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

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

p {
  margin-bottom: 1.2rem;
  font-size: 1.0625rem; /* 17px */
}

p:last-child {
  margin-bottom: 0;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(2.25rem, 4vw, 3.5rem); margin-bottom: 1rem; } /* 36px~56px */
h2 { font-size: clamp(1.65rem, 2.8vw, 2.35rem); margin-bottom: 1rem; } /* 26px~38px */
h3 { font-size: clamp(1.25rem, 2vw, 1.5rem); margin-bottom: 0.75rem; } /* 20px~24px */
h4 { font-size: 1.15rem; margin-bottom: 0.5rem; }

/* Structural Containers */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section-padding {
  padding: 5rem 0;
}

/* Header & Navigation */
.site-header {
  height: var(--header-height);
  background-color: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
}

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

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
}

.brand-subtitle {
  font-size: 0.8125rem;
  color: var(--muted);
  border-left: 1px solid var(--border);
  padding-left: 0.75rem;
  white-space: nowrap;
}

.nav-desktop {
  display: flex;
  align-items: center;
  gap: 1.35rem;
}

.nav-link {
  font-size: 0.9375rem;
  color: var(--text);
  font-weight: 500;
  position: relative;
  padding: 0.25rem 0;
}

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

.nav-link.active {
  color: var(--brick);
  font-weight: 700;
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 65%;
  height: 2px;
  background-color: var(--brick);
}

.btn-cta {
  background-color: var(--brick);
  color: var(--paper) !important;
  padding: 0.55rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.9375rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  border: 1px solid transparent;
  transition: all 0.2s ease;
}

.btn-cta:hover {
  background-color: var(--brick-dark);
  color: var(--paper) !important;
}

.btn-secondary {
  background-color: var(--paper);
  color: var(--text);
  padding: 0.55rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.9375rem;
  font-weight: 600;
  border: 1px solid var(--border);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: all 0.2s ease;
}

.btn-secondary:hover {
  border-color: var(--brick);
  color: var(--brick);
  background-color: var(--surface);
}

/* Mobile Menu Toggle */
.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);
  font-size: 1.1rem;
}

.nav-mobile {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background-color: var(--bg);
  border-bottom: 2px solid var(--border);
  padding: 1.5rem;
  z-index: 999;
  flex-direction: column;
  gap: 1rem;
  box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

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

.nav-mobile .nav-link {
  font-size: 1.05rem;
  padding: 0.5rem 0;
  border-bottom: 1px dashed var(--border);
}

/* ==========================================================================
   Center Seam System Core Layouts (中缝对照系统)
   ========================================================================== */
.seam-section {
  position: relative;
  border-bottom: 1px solid var(--border);
}

/* Asymmetric seam grids for different sections */
.seam-grid {
  display: grid;
  position: relative;
  gap: 0;
}

.seam-grid-hero { grid-template-columns: 42% 58%; }
.seam-grid-price { grid-template-columns: 38% 62%; }
.seam-grid-data { grid-template-columns: 57% 43%; }
.seam-grid-node { grid-template-columns: 45% 55%; }
.seam-grid-line { grid-template-columns: 40% 60%; }
.seam-grid-ai { grid-template-columns: 60% 40%; }
.seam-grid-video { grid-template-columns: 48% 52%; }
.seam-grid-client { grid-template-columns: 44% 56%; }
.seam-grid-review { grid-template-columns: 52% 48%; }
.seam-grid-misconception { grid-template-columns: 50% 50%; }

/* The Seam Line Decorator */
.seam-col-left {
  padding: 2.5rem 2.5rem 2.5rem 0;
  position: relative;
}

.seam-col-right {
  padding: 2.5rem 0 2.5rem 2.5rem;
  position: relative;
  border-left: 1px solid var(--seam);
}

/* Broken Seam effect (2-3 missing gap segments) */
.seam-col-right.broken-seam-top::before {
  content: '';
  position: absolute;
  top: 15%;
  left: -1px;
  width: 1px;
  height: 40px;
  background-color: var(--bg);
  z-index: 2;
}

.seam-col-right.broken-seam-bottom::after {
  content: '';
  position: absolute;
  bottom: 20%;
  left: -1px;
  width: 1px;
  height: 50px;
  background-color: var(--bg);
  z-index: 2;
}

/* Labels on Left / Right columns */
.seam-label-surface {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--brick);
  background-color: var(--brick-soft);
  padding: 0.2rem 0.65rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.25rem;
}

.seam-label-judgment {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--sage-dark);
  background-color: var(--sage-soft);
  padding: 0.2rem 0.65rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.25rem;
}

/* Section Header Bar */
.section-header-bar {
  margin-bottom: 2.5rem;
}

.section-num-tag {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--brick);
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
  display: block;
}

.section-title {
  font-size: clamp(1.6rem, 2.5vw, 2.25rem);
  color: var(--text);
}

.direct-answer-box {
  background-color: var(--paper);
  border-left: 3px solid var(--brick);
  padding: 1.25rem 1.5rem;
  margin-bottom: 2rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  border-top: 1px solid var(--border);
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.direct-answer-title {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--brick-dark);
  margin-bottom: 0.35rem;
}

.direct-answer-text {
  font-size: 1.05rem;
  color: var(--text);
  font-weight: 500;
  line-height: 1.7;
}

/* ==========================================================================
   Hero Section Styling
   ========================================================================== */
.hero-section {
  padding: 4rem 0 5rem 0;
  background-color: var(--bg);
  position: relative;
  border-bottom: 1px solid var(--border);
}

.hero-brand-straddle {
  background-color: var(--paper);
  border: 1px solid var(--border);
  padding: 2.25rem;
  border-radius: var(--radius-md);
  margin-bottom: 2.5rem;
  position: relative;
  z-index: 5;
}

.hero-tagline {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--brick);
  margin-bottom: 0.75rem;
}

.hero-h1 {
  font-size: clamp(2rem, 3.5vw, 3.25rem);
  color: var(--text);
  margin-bottom: 1rem;
  line-height: 1.25;
}

.hero-desc {
  font-size: 1.125rem;
  color: var(--body);
  max-width: 900px;
  line-height: 1.8;
  margin-bottom: 1.75rem;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.hero-sublink {
  font-size: 0.9375rem;
  color: var(--sage-dark);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.hero-sublink:hover {
  color: var(--brick);
}

.hero-pill-list {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.hero-pill-item-surface {
  background-color: var(--brick-soft);
  border: 1px solid var(--border);
  padding: 0.75rem 1.15rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  color: var(--brick-dark);
  font-size: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.hero-pill-item-judgment {
  background-color: var(--sage-soft);
  border: 1px solid var(--border);
  padding: 0.75rem 1.15rem;
  border-radius: var(--radius-sm);
  font-weight: 500;
  color: var(--sage-dark);
  font-size: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* ==========================================================================
   Contrast Cards & Blocks
   ========================================================================== */
.contrast-card-surface {
  background-color: var(--paper);
  border: 1px solid var(--border);
  border-top: 3px solid var(--brick);
  padding: 1.5rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.25rem;
}

.contrast-card-judgment {
  background-color: var(--paper);
  border: 1px solid var(--border);
  border-top: 3px solid var(--sage);
  padding: 1.5rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.25rem;
}

.contrast-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.contrast-card-surface .contrast-title { color: var(--brick-dark); }
.contrast-card-judgment .contrast-title { color: var(--sage-dark); }

/* ==========================================================================
   HTML Line Comparison Table (Section 04)
   ========================================================================== */
.table-wrapper {
  width: 100%;
  overflow-x: auto;
  margin: 1.5rem 0;
  background-color: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
}

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

.seam-table th {
  background-color: var(--sand-soft);
  color: var(--text);
  font-weight: 700;
  padding: 1rem 1.25rem;
  border-bottom: 2px solid var(--border);
}

.seam-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  color: var(--body);
  vertical-align: top;
}

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

.seam-table tr:hover td {
  background-color: var(--sage-soft);
}

.table-tag {
  display: inline-block;
  font-weight: 700;
  color: var(--brick);
  background-color: var(--brick-soft);
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
}

/* ==========================================================================
   Seam Pricing Table (Section 08)
   ========================================================================== */
.pricing-section {
  background-color: var(--paper);
  padding: 5rem 0;
  border-bottom: 1px solid var(--border);
}

.pricing-table-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 2rem;
}

.pricing-row {
  display: grid;
  grid-template-columns: 32% 36% 32%;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  align-items: center;
  transition: border-color 0.2s;
}

.pricing-row:hover {
  border-color: var(--brick);
}

.pricing-row.primary-plan {
  background-color: var(--sage-soft);
  border: 2px solid var(--brick);
  position: relative;
}

.primary-badge {
  position: absolute;
  top: 0;
  right: 1.5rem;
  background-color: var(--brick);
  color: var(--paper);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  letter-spacing: 0.05em;
}

.pricing-col-left {
  padding: 1.5rem 1.5rem 1.5rem 1.75rem;
}

.pricing-user-scenario {
  font-size: 0.95rem;
  color: var(--body);
  line-height: 1.6;
}

.pricing-user-title {
  font-weight: 700;
  color: var(--text);
  font-size: 1.05rem;
  margin-bottom: 0.35rem;
}

.pricing-col-center {
  padding: 1.5rem;
  border-left: 1px solid var(--seam);
  border-right: 1px solid var(--seam);
  text-align: center;
  background-color: var(--paper);
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.pricing-traffic {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--brick);
  margin-bottom: 0.25rem;
}

.pricing-price {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--text);
  line-height: 1.1;
}

.pricing-price-unit {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
}

.pricing-col-right {
  padding: 1.5rem 1.75rem 1.5rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.pricing-plan-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
}

/* ==========================================================================
   Misconception List (Section 10)
   ========================================================================== */
.misconception-grid {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-top: 2rem;
}

.misconception-item {
  display: grid;
  grid-template-columns: 45% 55%;
  background-color: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.misconception-left {
  padding: 1.25rem 1.5rem;
  background-color: var(--brick-soft);
  border-right: 1px solid var(--seam);
}

.misconception-right {
  padding: 1.25rem 1.5rem;
  background-color: var(--sage-soft);
}

.misconception-myth-title {
  font-weight: 700;
  color: var(--brick-dark);
  font-size: 1.05rem;
  margin-bottom: 0.25rem;
}

.misconception-truth-title {
  font-weight: 700;
  color: var(--sage-dark);
  font-size: 1.05rem;
  margin-bottom: 0.25rem;
}

/* ==========================================================================
   Article Hub & Directory Grid (Section 11)
   ========================================================================== */
.article-hub-group {
  margin-bottom: 2.5rem;
  background-color: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.75rem;
}

.article-group-title {
  font-size: 1.25rem;
  color: var(--brick);
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.75rem;
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.article-item-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.article-row-item {
  display: grid;
  grid-template-columns: 280px 1fr auto;
  align-items: center;
  gap: 1.25rem;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background-color: var(--bg);
  transition: background 0.2s, border-color 0.2s;
}

.article-row-item:hover {
  background-color: var(--surface);
  border-color: var(--brick);
}

.article-row-title {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
}

.article-row-summary {
  font-size: 0.9375rem;
  color: var(--body);
}

.article-meta-info {
  font-size: 0.8125rem;
  color: var(--muted);
  white-space: nowrap;
}

/* ==========================================================================
   Cognitive FAQ Accordion (Section 12)
   ========================================================================== */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 2rem;
}

.faq-item {
  background-color: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.faq-summary-btn {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 1.25rem 1.5rem;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-family: inherit;
}

.faq-summary-btn:hover {
  color: var(--brick);
}

.faq-toggle-icon {
  font-size: 1.25rem;
  color: var(--brick);
  transition: transform 0.2s;
}

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

.faq-answer-body {
  padding: 0 1.5rem 1.5rem 1.5rem;
  color: var(--body);
  border-top: 1px dashed var(--border);
  margin-top: 0.5rem;
  padding-top: 1rem;
  font-size: 1rem;
  line-height: 1.8;
}

/* Standard details/summary html fallback */
details.faq-details {
  background-color: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 1rem;
}

details.faq-details summary {
  padding: 1.25rem 1.5rem;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  cursor: pointer;
}

details.faq-details summary:hover {
  color: var(--brick);
}

details.faq-details .faq-answer-inner {
  padding: 0 1.5rem 1.5rem 1.5rem;
  border-top: 1px dashed var(--border);
  margin-top: 0.5rem;
  padding-top: 1rem;
}

/* ==========================================================================
   Editorial Subpages (Articles, Category, Legal) Styling
   ========================================================================== */
.breadcrumb-nav {
  padding: 1.25rem 0;
  font-size: 0.875rem;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
  margin-bottom: 2.5rem;
}

.breadcrumb-nav a {
  color: var(--body);
}

.breadcrumb-nav a:hover {
  color: var(--brick);
}

.breadcrumb-sep {
  margin: 0 0.5rem;
  color: var(--muted);
}

/* Article Hero & Quick Conclusion */
.article-header {
  margin-bottom: 2.5rem;
}

.article-category-badge {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--brick);
  background-color: var(--brick-soft);
  padding: 0.2rem 0.65rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1rem;
}

.article-quick-conclusion {
  background-color: var(--sage-soft);
  border-left: 4px solid var(--brick);
  border-top: 1px solid var(--border);
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 1.5rem 1.75rem;
  border-radius: var(--radius-sm);
  margin: 2rem 0;
}

.article-quick-conclusion-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--brick-dark);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.article-layout {
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: 3rem;
  align-items: start;
}

.article-content {
  background-color: var(--paper);
  border: 1px solid var(--border);
  padding: 3rem;
  border-radius: var(--radius-md);
  max-width: 820px;
}

.article-content h2 {
  font-size: 1.65rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}

.article-content h3 {
  font-size: 1.3rem;
  margin-top: 1.75rem;
  margin-bottom: 0.75rem;
  color: var(--brick-dark);
}

.article-content ul, .article-content ol {
  margin-bottom: 1.5rem;
  padding-left: 1.75rem;
}

.article-content li {
  margin-bottom: 0.5rem;
  line-height: 1.8;
}

/* Sidebar Table of Contents */
.toc-sidebar {
  position: sticky;
  top: calc(var(--header-height) + 2rem);
  background-color: var(--paper);
  border: 1px solid var(--border);
  padding: 1.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
}

.toc-title {
  font-weight: 700;
  color: var(--text);
  font-size: 1rem;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.5rem;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.toc-list a {
  color: var(--body);
  display: block;
  line-height: 1.5;
}

.toc-list a:hover, .toc-list a.active {
  color: var(--brick);
  font-weight: 600;
}

/* Category Hero & Layout */
.category-hero {
  background-color: var(--sand-soft);
  border: 1px solid var(--border);
  padding: 3rem 2.5rem;
  border-radius: var(--radius-md);
  margin-bottom: 3rem;
}

.category-hero-contrast {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-top: 1.5rem;
  background-color: var(--paper);
  padding: 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   Dark Charcoal Footer (深炭对照目录型 Footer)
   ========================================================================== */
.site-footer {
  background-color: var(--charcoal);
  color: var(--paper);
  padding: 4.5rem 0 2.5rem 0;
  border-top: 3px solid var(--brick);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3.5rem;
}

.footer-brand-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--paper);
  margin-bottom: 0.5rem;
}

.footer-brand-desc {
  font-size: 0.9375rem;
  color: #CEC6BB;
  line-height: 1.7;
  margin-bottom: 1.25rem;
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--brick);
  margin-bottom: 1.25rem;
  letter-spacing: 0.02em;
}

.footer-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-nav-list a {
  color: #CEC6BB;
  font-size: 0.9375rem;
}

.footer-nav-list a:hover {
  color: var(--sage);
}

.footer-friends-bar {
  border-top: 1px solid #484642;
  border-bottom: 1px solid #484642;
  padding: 1.25rem 0;
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  font-size: 0.875rem;
  color: #CEC6BB;
}

.footer-friends-title {
  font-weight: 700;
  color: var(--paper);
}

.footer-friends-link {
  color: #CEC6BB;
}

.footer-friends-link:hover {
  color: var(--sage);
  text-decoration: underline;
}

.footer-copyright-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.875rem;
  color: #CEC6BB;
}

/* Accessibility & Print */
@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;
  }
}

/* ==========================================================================
   Responsive Breakpoints: 1440, 1024, 768, 430, 390, 375
   ========================================================================== */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }
  .article-layout {
    grid-template-columns: 1fr;
  }
  .toc-sidebar {
    display: none;
  }
  .article-row-item {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }
}

@media (max-width: 768px) {
  .nav-desktop {
    display: none;
  }
  .mobile-menu-btn {
    display: block;
  }
  .brand-subtitle {
    display: none;
  }

  /* Center Seam System Responsive Conversion: 2 Columns -> Vertical Stack */
  .seam-grid {
    grid-template-columns: 1fr !important;
  }

  .seam-col-left {
    padding: 1.5rem 0 0 0;
  }

  .seam-col-right {
    padding: 1.5rem 0 0 0;
    border-left: none;
    border-top: 1px solid var(--seam);
    margin-top: 1.5rem;
  }

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

  .pricing-col-center {
    border-left: none;
    border-right: none;
    border-top: 1px dashed var(--border);
    border-bottom: 1px dashed var(--border);
    padding: 1rem;
  }

  .pricing-col-right {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }

  .misconception-item {
    grid-template-columns: 1fr;
  }

  .misconception-left {
    border-right: none;
    border-bottom: 1px solid var(--seam);
  }

  .category-hero-contrast {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-copyright-bar {
    flex-direction: column;
    gap: 1rem;
    align-items: flex-start;
  }
}

@media (max-width: 430px) {
  .container {
    padding: 0 1rem;
  }
  .section-padding {
    padding: 3.5rem 0;
  }
  .hero-section {
    padding: 2.5rem 0 3.5rem 0;
  }
  .hero-brand-straddle {
    padding: 1.5rem;
  }
  .article-content {
    padding: 1.5rem;
  }
}