/* ============================================
   RS & GIS Blog — Design System
   Version: 1.0.0
   Last Updated: 2026-07-20
   ============================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* — Color Palette (GIS / Earth Observation inspired) — */
  --color-primary: #0B3D91;
  --color-primary-light: #1A56C4;
  --color-primary-dark: #072A66;
  --color-primary-alpha: rgba(11, 61, 145, 0.12);

  --color-secondary: #00838F;
  --color-secondary-light: #00ACC1;
  --color-secondary-dark: #005662;

  --color-accent: #E67E22;
  --color-accent-light: #F39C12;
  --color-accent-dark: #D35400;

  --color-success: #27AE60;
  --color-warning: #F1C40F;
  --color-error: #E74C3C;

  /* — Surfaces — */
  --bg-body: #F1F5F9;
  --bg-surface: #FFFFFF;
  --bg-surface-raised: #FFFFFF;
  --bg-surface-overlay: rgba(255, 255, 255, 0.95);
  --bg-muted: #EEF2F7;
  --bg-code: #F1F5F9;

  /* — Text — */
  --text-primary: #0F172A;
  --text-secondary: #334155;
  --text-muted: #475569;
  --text-inverse: #FFFFFF;
  --text-link: var(--color-primary);
  --text-link-hover: var(--color-primary-light);

  /* — Borders — */
  --border-color: #E2E8F0;
  --border-color-strong: #CBD5E1;
  --border-radius-sm: 6px;
  --border-radius: 10px;
  --border-radius-lg: 16px;
  --border-radius-xl: 24px;
  --border-radius-full: 9999px;

  /* — Shadows — */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-card-hover: 0 8px 24px rgba(0, 0, 0, 0.1);

  /* — Typography — */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;

  --text-xs: clamp(0.7rem, 0.66rem + 0.2vw, 0.78rem);
  --text-sm: clamp(0.8rem, 0.76rem + 0.2vw, 0.875rem);
  --text-base: clamp(0.938rem, 0.9rem + 0.2vw, 1rem);
  --text-lg: clamp(1.05rem, 1rem + 0.25vw, 1.125rem);
  --text-xl: clamp(1.15rem, 1.06rem + 0.45vw, 1.25rem);
  --text-2xl: clamp(1.35rem, 1.2rem + 0.75vw, 1.5rem);
  --text-3xl: clamp(1.6rem, 1.35rem + 1.25vw, 1.875rem);
  --text-4xl: clamp(1.9rem, 1.5rem + 2vw, 2.25rem);
  --text-5xl: clamp(2.2rem, 1.6rem + 3vw, 3rem);

  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.6;
  --leading-relaxed: 1.75;
  --letter-tight: -0.025em;
  --letter-normal: 0;
  --letter-wide: 0.025em;

  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  --font-extrabold: 800;

  /* — Spacing — */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-section: clamp(3rem, 2rem + 5vw, 6rem);

  /* — Layout — */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 960px;
  --container-xl: 1140px;
  --container-2xl: 1280px;
  --content-width: 720px;
  --sidebar-width: 300px;
  --nav-height: 64px;

  /* — Transitions — */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-spring: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* — Z-index scale — */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-overlay: 300;
  --z-modal: 400;
  --z-toast: 500;

  /* — Misc — */
  --gradient-hero: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 50%, var(--color-primary-dark) 100%);
  --gradient-card: linear-gradient(180deg, transparent 0%, var(--bg-surface) 100%);
  --gradient-text: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
}

/* ---------- Dark Mode ---------- */
[data-theme="dark"] {
  --color-primary: #4B8BF5;
  --color-primary-light: #6FA3FF;
  --color-primary-dark: #2D6CE0;
  --color-primary-alpha: rgba(75, 139, 245, 0.15);

  --color-secondary: #26C6DA;
  --color-secondary-light: #4DD0E1;
  --color-secondary-dark: #00ACC1;

  --color-accent: #FFB74D;
  --color-accent-light: #FFCC80;
  --color-accent-dark: #FFA726;

  --bg-body: #0D1117;
  --bg-surface: #161B22;
  --bg-surface-raised: #1C2333;
  --bg-surface-overlay: rgba(22, 27, 34, 0.96);
  --bg-muted: #1C2333;
  --bg-code: #1C2333;

  --text-primary: #E6EDF3;
  --text-secondary: #A8B9CF;
  --text-muted: #7B8FA7;
  --text-inverse: #0D1117;
  --text-link: var(--color-primary);
  --text-link-hover: var(--color-primary-light);

  --border-color: #2A3140;
  --border-color-strong: #3D4A5C;

  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.25), 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.35), 0 4px 6px -4px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.25);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-card-hover: 0 8px 24px rgba(0, 0, 0, 0.35);

  --gradient-hero: linear-gradient(135deg, #0a1628 0%, #0f2847 50%, #0B3D91 100%);
}

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

html {
  font-size: 100%;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: calc(var(--nav-height) + 1rem);
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--text-primary);
  background-color: var(--bg-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-slow), color var(--transition-slow);
}

main {
  flex: 1;
}

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

input, button, textarea, select {
  font: inherit;
  color: inherit;
}

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

a:hover {
  color: var(--text-link-hover);
}

a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: 2px;
}

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: var(--font-bold);
  line-height: var(--leading-tight);
  letter-spacing: var(--letter-tight);
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

p {
  margin-bottom: var(--space-4);
  color: var(--text-secondary);
}

::selection {
  background-color: var(--color-primary-alpha);
  color: var(--text-primary);
}

/* ---------- Skip Link ---------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  background: var(--color-primary);
  color: var(--text-inverse);
  padding: var(--space-3) var(--space-6);
  border-radius: 0 0 var(--border-radius) var(--border-radius);
  z-index: var(--z-toast);
  font-weight: var(--font-semibold);
  font-size: var(--text-sm);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 0;
  color: var(--text-inverse);
}

/* ---------- Utilities ---------- */
.container {
  width: 100%;
  max-width: var(--container-xl);
  margin-inline: auto;
  padding-inline: var(--space-5);
}

@media (min-width: 768px) {
  .container { padding-inline: var(--space-8); }
}

@media (min-width: 1200px) {
  .container { padding-inline: var(--space-12); }
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.section {
  padding-block: var(--space-section);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-12);
}

.section-header h2 {
  margin-bottom: var(--space-4);
}

.section-header p {
  max-width: 600px;
  margin-inline: auto;
  font-size: var(--text-lg);
}

.section-label {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: var(--font-bold);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
  padding: var(--space-1) var(--space-3);
  background: var(--color-primary-alpha);
  border-radius: var(--border-radius-full);
}

/* ---------- Navbar ---------- */
.navbar {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background: var(--bg-surface-overlay);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  height: var(--nav-height);
  transition: background-color var(--transition-slow), border-color var(--transition-slow), box-shadow var(--transition-base);
}

.navbar.scrolled {
  box-shadow: var(--shadow-sm);
}

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

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-weight: var(--font-bold);
  font-size: var(--text-lg);
  color: var(--text-primary);
  text-decoration: none;
  flex-shrink: 0;
}

.nav-brand:hover {
  color: var(--color-primary);
}

.nav-brand svg {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}

.nav-brand-text span {
  display: block;
  font-size: var(--text-xs);
  font-weight: var(--font-normal);
  color: var(--text-muted);
  line-height: 1;
  margin-top: 2px;
}

.nav-links {
  display: none;
  margin-left: auto;
  align-items: center;
  gap: var(--space-1);
}

@media (min-width: 768px) {
  .nav-links { display: flex; }
}

.nav-links a {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
  border-radius: var(--border-radius);
  transition: color var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--color-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* Theme toggle */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: var(--border-radius);
  background: transparent;
  cursor: pointer;
  color: var(--text-secondary);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.theme-toggle:hover {
  color: var(--color-accent);
  background: var(--color-primary-alpha);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

.theme-toggle .icon-moon { display: block; }
.theme-toggle .icon-sun { display: none; }
[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
[data-theme="dark"] .theme-toggle .icon-sun { display: block; }

/* Mobile menu button */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: var(--border-radius);
  background: transparent;
  cursor: pointer;
  color: var(--text-primary);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-toggle:hover {
  background: var(--color-primary-alpha);
}

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

.nav-toggle .icon-close { display: none; }
.nav-toggle[aria-expanded="true"] .icon-menu { display: none; }
.nav-toggle[aria-expanded="true"] .icon-close { display: block; }

.nav-toggle svg {
  width: 22px;
  height: 22px;
}

/* Mobile menu */
#mobile-nav.open {
  display: flex !important;
  flex-direction: column;
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 1rem;
  left: 1rem;
  background: var(--bg-surface-overlay, #ffffff);
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  padding: var(--space-2) 0;
  z-index: var(--z-overlay);
}

#mobile-nav.open .nav-link, #mobile-nav.open a {
  justify-content: flex-start !important;
  padding: 12px 24px !important;
}




@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

#mobile-nav.open a {
  display: block;
  padding: var(--space-4) var(--space-2);
  font-size: var(--text-lg);
  font-weight: var(--font-medium);
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

#mobile-nav.open a:hover {
  color: var(--color-primary);
  padding-left: var(--space-4);
}

@media (min-width: 768px) {
  #mobile-nav.open {
  display: flex !important;
  flex-direction: column;
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 1rem;
  left: 1rem;
  background: var(--bg-surface-overlay, #ffffff);
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  padding: var(--space-2) 0;
  z-index: var(--z-overlay);
}

#mobile-nav.open .nav-link, #mobile-nav.open a {
  justify-content: flex-start !important;
  padding: 12px 24px !important;
}

}

/* ---------- Hero Section ---------- */
.hero {
  position: relative;
  background: var(--gradient-hero);
  color: #FFFFFF;
  padding: clamp(4rem, 3rem + 5vw, 8rem) 0;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 70% 20%, rgba(0, 131, 143, 0.25) 0%, transparent 60%),
              radial-gradient(ellipse at 20% 80%, rgba(230, 126, 34, 0.15) 0%, transparent 50%);
  pointer-events: none;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 700px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--border-radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-6);
  color: rgba(255, 255, 255, 0.9);
}

.hero-badge svg {
  width: 14px;
  height: 14px;
}

.hero h1 {
  color: #FFFFFF;
  margin-bottom: var(--space-6);
  font-weight: var(--font-extrabold);
  letter-spacing: -0.03em;
}

.hero-description {
  font-size: var(--text-lg);
  color: rgba(255, 255, 255, 0.8);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-8);
  max-width: 560px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.hero-stats {
  display: flex;
  gap: var(--space-10);
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.hero-stat-value {
  display: block;
  font-size: var(--text-3xl);
  font-weight: var(--font-extrabold);
}

.hero-stat-label {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.6);
  margin-top: var(--space-1);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  border-radius: var(--border-radius);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-fast);
  white-space: nowrap;
  line-height: 1.5;
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

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

.btn-primary:hover {
  background: #F0F4FF;
  color: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-outline {
  background: transparent;
  color: #FFFFFF;
  border: 1.5px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.5);
  color: #FFFFFF;
}

.btn-solid {
  background: var(--color-primary);
  color: #FFFFFF;
}

.btn-solid:hover {
  background: var(--color-primary-light);
  color: #FFFFFF;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-ghost {
  background: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--border-color);
}

.btn-ghost:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-alpha);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
  border-radius: var(--border-radius-lg);
}

/* ---------- Article Cards ---------- */
.articles-grid {
  display: grid;
  gap: var(--space-8);
}

@media (min-width: 640px) {
  .articles-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .articles-grid { grid-template-columns: repeat(3, 1fr); }
}

.article-card {
  display: flex;
  flex-direction: column;
  background: var(--bg-surface);
  border-radius: var(--border-radius-lg);
  border: 1px solid var(--border-color);
  border-top: 4px solid var(--color-primary);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-primary-alpha);
}

.article-card-image {
  position: relative;
  aspect-ratio: 16 / 9;
  background: var(--bg-muted);
  overflow: hidden;
}

.article-card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.article-card:hover .article-card-image img {
  transform: scale(1.04);
}

.article-card-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--bg-muted) 0%, var(--border-color) 100%);
}

.article-card-placeholder svg {
  width: 48px;
  height: 48px;
  color: var(--text-muted);
  opacity: 0.5;
}

.article-card-body {
  display: flex;
  flex-direction: column;
  flex: 1;
  padding: var(--space-6);
}

.article-card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

.article-card-category {
  display: inline-block;
  padding: var(--space-1) var(--space-2);
  background: var(--color-primary-alpha);
  color: var(--color-primary);
  border-radius: var(--border-radius-sm);
  font-weight: var(--font-semibold);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.article-card-title {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  line-height: var(--leading-snug);
  margin-bottom: var(--space-3);
}

.article-card-title a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.article-card-title a:hover {
  color: var(--color-primary);
}

.article-card-excerpt {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-5);
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-4);
  border-top: 1px solid var(--border-color);
}

.article-card-date {
  font-size: var(--text-xs);
  color: var(--text-muted);
}

.article-card-readmore {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-primary);
  transition: gap var(--transition-fast);
}

.article-card-readmore:hover {
  gap: var(--space-2);
}

.article-card-readmore svg {
  width: 16px;
  height: 16px;
}

/* Featured article card (larger) */
.article-card-featured {
  grid-column: 1 / -1;
}

@media (min-width: 768px) {
  .article-card-featured {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .article-card-featured .article-card-image {
    aspect-ratio: auto;
    min-height: 300px;
  }

  .article-card-featured .article-card-body {
    padding: var(--space-8);
    justify-content: center;
  }

  .article-card-featured .article-card-title {
    font-size: var(--text-2xl);
  }

  .article-card-featured .article-card-excerpt {
    -webkit-line-clamp: 4;
  }
}

/* ---------- Categories ---------- */
.categories-grid {
  display: grid;
  gap: var(--space-4);
  grid-template-columns: repeat(2, 1fr);
}

@media (min-width: 640px) {
  .categories-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 1024px) {
  .categories-grid { grid-template-columns: repeat(4, 1fr); }
}

.category-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-6) var(--space-4);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.category-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.category-card-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--border-radius);
  background: var(--color-primary-alpha);
  color: var(--color-primary);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.category-card:hover .category-card-icon {
  background: var(--color-primary);
  color: #FFFFFF;
}

.category-card-icon svg {
  width: 24px;
  height: 24px;
}

.category-card-name {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
}

.category-card-count {
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* ---------- About Preview ---------- */
.about-preview {
  display: grid;
  gap: var(--space-10);
  align-items: center;
}

@media (min-width: 768px) {
  .about-preview { grid-template-columns: 1fr 1.2fr; }
}

.about-preview-image {
  position: relative;
  aspect-ratio: 4 / 3;
  border-radius: var(--border-radius-xl);
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
}

.about-preview-image-inner {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.5;
}

.about-preview-image-inner svg {
  width: 80px;
  height: 80px;
  color: #FFFFFF;
}

.about-preview-content h2 {
  margin-bottom: var(--space-4);
}

.about-preview-content p {
  margin-bottom: var(--space-6);
  font-size: var(--text-lg);
  line-height: var(--leading-relaxed);
}

/* ---------- Newsletter ---------- */
.newsletter {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-xl);
  padding: var(--space-12) var(--space-8);
  text-align: center;
}

.newsletter h2 {
  margin-bottom: var(--space-3);
}

.newsletter p {
  max-width: 500px;
  margin-inline: auto;
  margin-bottom: var(--space-8);
  font-size: var(--text-lg);
}

.newsletter-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 480px;
  margin-inline: auto;
}

@media (min-width: 480px) {
  .newsletter-form {
    flex-direction: row;
  }
}

.newsletter-form input[type="email"] {
  flex: 1;
  padding: var(--space-3) var(--space-5);
  border: 1.5px solid var(--border-color);
  border-radius: var(--border-radius);
  background: var(--bg-body);
  font-size: var(--text-base);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  min-width: 0;
}

.newsletter-form input[type="email"]:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-alpha);
}

.newsletter-form input[type="email"]::placeholder {
  color: var(--text-muted);
}

.newsletter-form .btn {
  flex-shrink: 0;
}

.newsletter-note {
  font-size: var(--text-xs);
  color: var(--text-muted);
  margin-top: var(--space-4);
}

/* ---------- Footer ---------- */


.footer-grid {
  display: grid;
  gap: var(--space-10);
}

@media (min-width: 640px) {
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; }
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.footer-brand .nav-brand {
  font-size: var(--text-xl);
}

.footer-brand p {
  font-size: var(--text-sm);
  color: var(--text-muted);
  max-width: 300px;
}

.footer-social {
  display: flex;
  gap: var(--space-3);
  margin-top: var(--space-2);
}

.footer-social a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--border-radius);
  background: var(--bg-muted);
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  background: var(--color-primary);
  color: #FFFFFF;
  transform: translateY(-2px);
}

.footer-social a svg {
  width: 18px;
  height: 18px;
}

.footer-column h3 {
  font-size: var(--text-sm);
  font-weight: var(--font-bold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-primary);
  margin-bottom: var(--space-5);
}

.footer-column ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-column a {
  font-size: var(--text-sm);
  color: var(--text-muted);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.footer-column a:hover {
  color: var(--color-primary);
  padding-left: var(--space-1);
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  align-items: center;
  justify-content: space-between;
  padding: var(--space-6) 0;
  margin-top: var(--space-12);
  border-top: 1px solid var(--border-color);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

@media (min-width: 768px) {
  .footer-bottom { flex-direction: row; }
}

.footer-bottom-links {
  display: flex;
  gap: var(--space-6);
}

.footer-bottom-links a {
  color: var(--text-muted);
  font-size: var(--text-xs);
}

.footer-bottom-links a:hover {
  color: var(--color-primary);
}

/* ---------- Breadcrumbs ---------- */
.breadcrumbs {
  padding: var(--space-4) 0;
  font-size: var(--text-sm);
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}

.breadcrumbs li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--text-muted);
}

.breadcrumbs li:not(:last-child)::after {
  content: '';
  display: inline-block;
  width: 16px;
  height: 16px;
  background: currentColor;
  mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='9 18 15 12 9 6'%3E%3C/polyline%3E%3C/svg%3E");
  -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='9 18 15 12 9 6'%3E%3C/polyline%3E%3C/svg%3E");
  mask-size: contain;
  -webkit-mask-size: contain;
  flex-shrink: 0;
}

.breadcrumbs a {
  color: var(--text-muted);
}

.breadcrumbs a:hover {
  color: var(--color-primary);
}

.breadcrumbs [aria-current="page"] {
  color: var(--text-primary);
  font-weight: var(--font-medium);
}

/* ---------- Article (Single) ---------- */
.article-header {
  padding-top: var(--space-8);
  margin-bottom: var(--space-8);
}

.article-header-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-5);
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.article-header-meta .article-card-category {
  font-size: var(--text-xs);
}

.article-header h1 {
  margin-bottom: var(--space-5);
  max-width: 800px;
}

.article-header-description {
  font-size: var(--text-xl);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  max-width: 700px;
  margin-bottom: var(--space-6);
}

.article-featured-image {
  aspect-ratio: 21 / 9;
  border-radius: var(--border-radius-xl);
  overflow: hidden;
  margin-bottom: var(--space-10);
  background: linear-gradient(135deg, var(--bg-muted), var(--border-color));
}

.article-featured-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.article-layout {
  display: grid;
  gap: var(--space-10);
}

@media (min-width: 1024px) {
  .article-layout {
    grid-template-columns: 1fr var(--sidebar-width);
    align-items: start;
  }
}

.article-content {
  max-width: var(--content-width);
}

.article-content h2 {
  font-size: var(--text-3xl);
  margin-top: var(--space-12);
  margin-bottom: var(--space-5);
  padding-top: var(--space-4);
}

.article-content h3 {
  font-size: var(--text-2xl);
  margin-top: var(--space-10);
  margin-bottom: var(--space-4);
}

.article-content h4 {
  font-size: var(--text-xl);
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
}

.article-content p {
  margin-bottom: var(--space-5);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
}

.article-content ul,
.article-content ol {
  margin-bottom: var(--space-5);
  padding-left: var(--space-6);
}

.article-content ul { list-style: disc; }
.article-content ol { list-style: decimal; }

.article-content li {
  margin-bottom: var(--space-2);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

.article-content blockquote {
  margin: var(--space-6) 0;
  padding: var(--space-5) var(--space-6);
  border-left: 4px solid var(--color-primary);
  background: var(--color-primary-alpha);
  border-radius: 0 var(--border-radius) var(--border-radius) 0;
  font-style: italic;
  color: var(--text-secondary);
}

.article-content code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--bg-code);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  color: var(--color-primary);
}

.article-content pre {
  margin: var(--space-6) 0;
  padding: var(--space-5);
  background: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  overflow-x: auto;
}

.article-content pre code {
  background: transparent;
  padding: 0;
  color: var(--text-primary);
}

.article-content a {
  color: var(--color-primary);
  text-decoration: underline;
  text-decoration-color: var(--color-primary-alpha);
  text-underline-offset: 3px;
  transition: text-decoration-color var(--transition-fast);
}

.article-content a:hover {
  text-decoration-color: var(--color-primary);
}

.article-content img {
  border-radius: var(--border-radius);
  margin: var(--space-6) 0;
}

.article-content figure {
  margin: var(--space-8) 0;
}

.article-content figcaption {
  text-align: center;
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-top: var(--space-3);
}

/* Table of Contents */
.toc {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-8));
}

.toc-inner {
  padding: var(--space-6);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
}

.toc-title {
  font-size: var(--text-sm);
  font-weight: var(--font-bold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-4);
  color: var(--text-primary);
}

.toc-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.toc-list a {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  color: var(--text-muted);
  border-left: 2px solid transparent;
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
  transition: all var(--transition-fast);
}

.toc-list a:hover,
.toc-list a.active {
  color: var(--color-primary);
  background: var(--color-primary-alpha);
  border-left-color: var(--color-primary);
}

.toc-list .toc-h3 {
  padding-left: var(--space-6);
  font-size: var(--text-xs);
}

/* Sidebar mobile toggle */
.toc-mobile-toggle {
  display: block;
  width: 100%;
  margin-bottom: var(--space-6);
  text-align: left;
}

@media (min-width: 1024px) {
  .toc-mobile-toggle { display: none; }
  .toc-mobile-content { display: block !important; }
}

/* ---------- Author Box ---------- */
.author-box {
  display: flex;
  gap: var(--space-5);
  padding: var(--space-6);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  margin-top: var(--space-10);
}

.author-box-avatar {
  width: 64px;
  height: 64px;
  border-radius: var(--border-radius-full);
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: #FFFFFF;
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
}

.author-box-name {
  font-size: var(--text-lg);
  font-weight: var(--font-bold);
  margin-bottom: var(--space-1);
}

.author-box-title {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-bottom: var(--space-3);
}

.author-box-bio {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

/* ---------- FAQ Section ---------- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  max-width: var(--content-width);
}

.faq-item {
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--color-primary-alpha);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--space-5) var(--space-6);
  background: var(--bg-surface);
  border: none;
  cursor: pointer;
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  text-align: left;
  gap: var(--space-4);
  transition: background var(--transition-fast);
}

.faq-question:hover {
  background: var(--bg-muted);
}

.faq-question svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--text-muted);
  transition: transform var(--transition-base);
}

.faq-item.open .faq-question svg {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.faq-answer-inner {
  padding: 0 var(--space-6) var(--space-6);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

.faq-item.open .faq-answer {
  max-height: 500px;
}

/* ---------- References ---------- */
.references-list {
  counter-reset: ref-counter;
}

.references-list li {
  counter-increment: ref-counter;
  padding-left: var(--space-2);
  margin-bottom: var(--space-3);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

.references-list li::marker {
  content: "[" counter(ref-counter) "] ";
  font-weight: var(--font-semibold);
  color: var(--color-primary);
}

/* ---------- Related Articles ---------- */
.related-articles {
  margin-top: var(--space-16);
  padding-top: var(--space-12);
  border-top: 1px solid var(--border-color);
}

/* ---------- Share Buttons ---------- */
.share-bar {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-5) 0;
  margin: var(--space-6) 0;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.share-bar-label {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--text-secondary);
  margin-right: var(--space-2);
}

.share-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.share-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-alpha);
}

.share-btn svg {
  width: 16px;
  height: 16px;
}

/* ---------- Page Headers ---------- */
.page-header {
  background: var(--bg-muted);
  padding: var(--space-12) 0;
  margin-bottom: var(--space-section);
  border-bottom: 1px solid var(--border-color);
}

.page-header h1 {
  margin-bottom: var(--space-3);
}

.page-header p {
  font-size: var(--text-lg);
  max-width: 600px;
}

/* ---------- Contact Form ---------- */
.contact-grid {
  display: grid;
  gap: var(--space-10);
}

@media (min-width: 768px) {
  .contact-grid { grid-template-columns: 1fr 1fr; }
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-group label {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
}

.form-group input,
.form-group textarea,
.form-group select {
  padding: var(--space-3) var(--space-4);
  border: 1.5px solid var(--border-color);
  border-radius: var(--border-radius);
  background: var(--bg-body);
  font-size: var(--text-base);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-alpha);
}

.form-group textarea {
  resize: vertical;
  min-height: 140px;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

.contact-info-item {
  display: flex;
  gap: var(--space-4);
}

.contact-info-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--border-radius);
  background: var(--color-primary-alpha);
  color: var(--color-primary);
  flex-shrink: 0;
}

.contact-info-icon svg {
  width: 20px;
  height: 20px;
}

.contact-info-label {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-1);
}

.contact-info-value {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

/* ---------- Legal Pages ---------- */
.legal-content {
  max-width: var(--content-width);
  margin-inline: auto;
}

.legal-content h2 {
  font-size: var(--text-2xl);
  margin-top: var(--space-10);
  margin-bottom: var(--space-4);
}

.legal-content h3 {
  font-size: var(--text-xl);
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
}

.legal-content p {
  margin-bottom: var(--space-4);
  line-height: var(--leading-relaxed);
}

.legal-content ul {
  list-style: disc;
  padding-left: var(--space-6);
  margin-bottom: var(--space-4);
}

.legal-content li {
  margin-bottom: var(--space-2);
  color: var(--text-secondary);
}

.legal-date {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-top: var(--space-2);
}

/* ---------- 404 Page ---------- */
.error-page {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  text-align: center;
  padding: var(--space-12) var(--space-4);
}

.error-code {
  font-size: clamp(6rem, 5rem + 8vw, 12rem);
  font-weight: var(--font-extrabold);
  background: var(--gradient-text);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1;
  margin-bottom: var(--space-4);
}

.error-page h1 {
  font-size: var(--text-3xl);
  margin-bottom: var(--space-4);
}

.error-page p {
  font-size: var(--text-lg);
  max-width: 500px;
  margin-inline: auto;
  margin-bottom: var(--space-8);
}

/* ---------- Reading Progress ---------- */
.reading-progress {
  position: fixed;
  top: var(--nav-height);
  left: 0;
  width: 0;
  height: 3px;
  background: var(--gradient-text);
  z-index: var(--z-sticky);
  transition: width 100ms linear;
}

/* ---------- Back to Top ---------- */
.back-to-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--border-radius-full);
  background: var(--color-primary);
  color: #FFFFFF;
  border: none;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition-base);
  z-index: var(--z-dropdown);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-primary-light);
  transform: translateY(-2px);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
}

/* ---------- Animations ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  opacity: 0;
  transform: translateY(20px);
}

.fade-in-up.visible {
  animation: fadeInUp 0.6s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

/* Staggered children */
.stagger-children .fade-in-up:nth-child(1) { animation-delay: 0ms; }
.stagger-children .fade-in-up:nth-child(2) { animation-delay: 80ms; }
.stagger-children .fade-in-up:nth-child(3) { animation-delay: 160ms; }
.stagger-children .fade-in-up:nth-child(4) { animation-delay: 240ms; }
.stagger-children .fade-in-up:nth-child(5) { animation-delay: 320ms; }
.stagger-children .fade-in-up:nth-child(6) { animation-delay: 400ms; }
.stagger-children .fade-in-up:nth-child(7) { animation-delay: 480ms; }
.stagger-children .fade-in-up:nth-child(8) { animation-delay: 560ms; }
.stagger-children .fade-in-up:nth-child(9) { animation-delay: 640ms; }
.stagger-children .fade-in-up:nth-child(10) { animation-delay: 720ms; }

/* ---------- 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;
  }

  .fade-in-up {
    opacity: 1;
    transform: none;
  }
}

/* ---------- Print ---------- */
@media print {
  .navbar,
  .mobile-nav,
  .back-to-top,
  .reading-progress,
  .share-bar,
  .newsletter,
  .theme-toggle,
  .nav-toggle,
  .site-footer {
    display: none !important;
  }

  body {
    color: #000;
    background: #fff;
  }

  .article-content a::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
    color: #666;
  }
}

/* ---------- Supplementary Article Styles ---------- */
.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.article-category {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  background: var(--color-primary-alpha);
  color: var(--color-primary);
  border-radius: var(--border-radius-sm);
  font-weight: var(--font-semibold);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.article-title {
  max-width: 800px;
}

.article-description {
  font-size: var(--text-xl);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
  max-width: 700px;
  margin-bottom: var(--space-6);
}

.article-author-mini {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.author-avatar-placeholder {
  width: 40px;
  height: 40px;
  border-radius: var(--border-radius-full);
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #FFFFFF;
  font-size: var(--text-sm);
  font-weight: var(--font-bold);
  flex-shrink: 0;
}

.author-name {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
}

.article-sidebar {
  order: -1;
}

@media (min-width: 1024px) {
  .article-sidebar {
    order: 1;
  }
}

.article-container {
  padding-bottom: var(--space-section);
}

.toc-container {
  padding: var(--space-6);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
}

.toc-container.sticky {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-8));
}

.toc-container .toc-title {
  font-size: var(--text-sm);
  font-weight: var(--font-bold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-4);
  color: var(--text-primary);
}

.toc-container nav ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.toc-container nav ul ul {
  padding-left: var(--space-4);
  margin-top: var(--space-1);
}

.toc-container nav a {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  color: var(--text-muted);
  border-left: 2px solid transparent;
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
  transition: all var(--transition-fast);
}

.toc-container nav a:hover,
.toc-container nav a.active {
  color: var(--color-primary);
  background: var(--color-primary-alpha);
  border-left-color: var(--color-primary);
}

/* Author box additional styles */
.author-avatar {
  width: 64px;
  height: 64px;
  border-radius: var(--border-radius-full);
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: #FFFFFF;
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
}

.author-info .author-name {
  font-size: var(--text-lg);
  font-weight: var(--font-bold);
  margin-bottom: var(--space-1);
}

.author-title,
.author-box-title {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-bottom: var(--space-3);
}

.author-bio {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

/* Article grid for related articles */
.article-grid {
  display: grid;
  gap: var(--space-6);
}

@media (min-width: 640px) {
  .article-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .article-grid { grid-template-columns: repeat(3, 1fr); }
}

.card-content {
  padding: var(--space-4);
}

.card-category {
  display: inline-block;
  padding: var(--space-1) var(--space-2);
  background: var(--color-primary-alpha);
  color: var(--color-primary);
  border-radius: var(--border-radius-sm);
  font-weight: var(--font-semibold);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-2);
}

.card-content h3 {
  font-size: var(--text-lg);
  margin-bottom: var(--space-2);
}

.card-content h3 a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.card-content h3 a:hover {
  color: var(--color-primary);
}

.card-content p {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.card-image-placeholder {
  background: var(--bg-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--border-radius) var(--border-radius) 0 0;
}

.image-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-muted);
  color: var(--text-muted);
  font-size: var(--text-sm);
}

/* Coming Soon notice */
.coming-soon-notice {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-6);
  background: var(--color-primary-alpha);
  border: 1px solid var(--color-primary);
  border-radius: var(--border-radius-lg);
  margin: var(--space-8) 0;
}

.coming-soon-notice svg {
  width: 24px;
  height: 24px;
  color: var(--color-primary);
  flex-shrink: 0;
}

.coming-soon-notice p {
  margin: 0;
  color: var(--text-secondary);
  font-size: var(--text-base);
}

/* About page specific */
.about-values {
  display: grid;
  gap: var(--space-6);
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.about-value-card {
  padding: var(--space-6);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  text-align: center;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.about-value-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.about-value-card svg {
  width: 40px;
  height: 40px;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.about-value-card h3 {
  font-size: var(--text-lg);
  margin-bottom: var(--space-2);
}

.about-value-card p {
  font-size: var(--text-sm);
}

/* Footer brand link additional styles */
.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-weight: var(--font-bold);
  font-size: var(--text-lg);
  color: var(--text-primary);
  text-decoration: none;
  margin-bottom: var(--space-3);
}

.footer-brand:hover {
  color: var(--color-primary);
}

.footer-brand svg {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

/* Footer column overrides for subagent pages */
.footer-col h3 {
  font-size: var(--text-sm);
  font-weight: var(--font-bold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-primary);
  margin-bottom: var(--space-5);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-col a {
  font-size: var(--text-sm);
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.footer-col a:hover {
  color: var(--color-primary);
}

.footer-container {
  padding-top: var(--space-16);
}

/* Homepage footer variant classes */
.footer-desc {
  font-size: var(--text-sm);
  color: var(--text-muted);
  max-width: 300px;
  margin-bottom: var(--space-4);
}

.social-links {
  display: flex;
  gap: var(--space-3);
}

.social-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--border-radius);
  background: var(--bg-muted);
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.social-links a:hover {
  background: var(--color-primary);
  color: #FFFFFF;
  transform: translateY(-2px);
}

.social-links a svg {
  width: 18px;
  height: 18px;
}

.footer-heading {
  font-size: var(--text-sm);
  font-weight: var(--font-bold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-primary);
  margin-bottom: var(--space-5);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--text-muted);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-primary);
  padding-left: var(--space-1);
}

/* Navbar brand variant */
.navbar-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-weight: var(--font-bold);
  font-size: var(--text-lg);
  color: var(--text-primary);
  text-decoration: none;
  flex-shrink: 0;
}

.navbar-brand:hover {
  color: var(--color-primary);
}

.navbar-brand svg {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
}

.nav-link {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--text-secondary);
  border-radius: var(--border-radius);
  transition: color var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
  background: var(--color-primary-alpha);
}

/* Article read more link */
.article-read-more {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-primary);
  transition: gap var(--transition-fast);
}

.article-read-more:hover {
  gap: var(--space-2);
}

.article-read-more svg {
  width: 16px;
  height: 16px;
}

/* Button variant for homepage */
.btn-secondary {
  background: transparent;
  color: #FFFFFF;
  border: 1.5px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.5);
  color: #FFFFFF;
}

/* ---------- Unified Footer ---------- */
.footer, .site-footer {
  background: var(--color-primary-dark);
  color: #FFFFFF;
  padding-top: var(--space-16);
  margin-top: auto;
  border-top: none;
}
.footer .footer-heading, .footer .footer-brand, .footer h3, .footer h4,
.site-footer .footer-heading, .site-footer .footer-brand, .site-footer h3, .site-footer h4,
.footer .copyright, .site-footer .copyright, .footer-bottom p {
  color: #FFFFFF !important;
}
.footer p, .footer a, .footer-links a, .footer-desc, .footer-social a, .footer-bottom-links a,
.site-footer p, .site-footer a, .site-footer .footer-muted {
  color: #94A3B8 !important;
}
.footer a:hover, .footer-links a:hover, .footer-social a:hover, .footer-bottom-links a:hover,
.site-footer a:hover {
  color: #FFFFFF !important;
}
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-6);
  padding-bottom: var(--space-6);
  margin-top: var(--space-10);
}

/* SEO Mobile Friendliness Fixes */
@media (max-width: 767px) {
  body { font-size: 16px !important; }
  .nav-link, .nav-links a { padding: 12px 16px !important; min-height: 48px; display: flex; align-items: center; justify-content: center; }
    .social-links a, .footer-social a { padding: 0 !important; width: 48px; height: 48px; }
  .btn, button, .article-read-more { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; }
}


/* --- UI Fixes --- */
@media (max-width: 768px) {
  .social-links a, .footer-social a {
    justify-content: center !important;
    align-items: center !important;
    display: inline-flex !important;
  }
  .article-featured-image img {
    height: auto !important;
    aspect-ratio: 16 / 9;
    max-height: 400px;
  }
}

.article-featured-image img {
    height: auto !important;
    aspect-ratio: 16 / 9;
    max-height: 500px;
}


/* Footer Logo Left Shift */
.footer-brand {
    margin-left: -16px !important;
}


/* ---------- Cookie Banner ---------- */
.cookie-banner {
  position: fixed;
  bottom: var(--space-4);
  left: var(--space-4);
  right: var(--space-4);
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: var(--space-4);
  box-shadow: var(--shadow-xl);
  z-index: var(--z-overlay);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  transition: opacity var(--transition-base);
}

@media (min-width: 640px) {
  .cookie-banner {
    max-width: 400px;
    left: auto;
  }
}

.cookie-banner p {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin: 0;
  line-height: 1.5;
}

.cookie-banner p a {
  color: var(--color-primary);
  font-weight: var(--font-medium);
}

.cookie-buttons {
  display: flex;
  gap: var(--space-3);
}

.cookie-buttons .btn {
  flex: 1;
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
}

.cookie-buttons .btn-secondary {
  background: transparent;
  color: var(--text-color);
  border: 1px solid var(--border-color);
}

.cookie-buttons .btn-secondary:hover {
  background: var(--bg-offset);
  color: var(--text-color);
  border-color: var(--border-color);
}