@import url('https://fonts.googleapis.com/css2?family=Fredoka:wght@500;600;700&family=Quicksand:wght@400;500;600;700&family=Nunito:wght@600;700;800&display=swap');

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

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

body {
  font-family: 'Quicksand', sans-serif;
  line-height: 1.7;
  min-height: 100vh;
}

/* === Design Tokens: Core Theme === */
body[data-theme="core"] {
  --primary: #F8A5B8;
  --primary-light: #FFCAD4;
  --primary-dark: #E8899C;
  --secondary: #7BC8F6;
  --secondary-light: #A5DDFB;
  --secondary-dark: #5AADE0;
  --accent: #C9A0DC;
  --accent-light: #DFC5EC;
  --accent-dark: #A87DC2;
  --success: #8ED16C;
  --warning: #F5916E;
  --bg-main: #FFF9F5;
  --bg-gradient: linear-gradient(135deg, #FFF9F5 0%, #F0F8FF 50%, #FFF5F8 100%);
  --card-bg: #FFFFFF;
  --border: #F0E6EB;
  --shadow: rgba(248, 165, 184, 0.15);
  --text-dark: #5D4E60;
  --text-medium: #6B5C70;
  --text-light: #807084;
}

body[data-theme] {
  --font-display: 'Fredoka', sans-serif;
  --font-body: 'Quicksand', sans-serif;
  --font-accent: 'Nunito', sans-serif;
  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 5rem;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s ease;
  --focus-ring: var(--accent-dark);
  --chrome-surface: rgba(255, 255, 255, 0.9);
  --chrome-surface-strong: rgba(255, 255, 255, 0.96);
  --chrome-shadow: 0 10px 32px var(--shadow);
  --surface-muted: color-mix(in srgb, var(--card-bg) 75%, var(--bg-main) 25%);
  --active-surface: var(--primary-light);
  --active-border: var(--primary-dark);
  --link-hover-surface: color-mix(in srgb, var(--primary-light) 55%, transparent);
  color-scheme: light;
}

body[data-shell="hub"] {
  --shell-main: 1100px;
  --shell-header: 1400px;
}

body[data-shell="article"] {
  --shell-main: 900px;
  --shell-header: 1400px;
}

/* === Background & Body === */
body[data-theme] {
  background: var(--bg-main);
  color: var(--text-dark);
  overflow-x: hidden;
}

body[data-theme]::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    var(--bg-gradient),
    radial-gradient(circle at 20% 20%, rgba(248, 165, 184, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 80% 15%, rgba(123, 200, 246, 0.10) 0%, transparent 40%),
    radial-gradient(circle at 50% 75%, rgba(201, 160, 220, 0.10) 0%, transparent 45%);
  pointer-events: none;
  z-index: -1;
}

/* === Skip Link === */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 200;
  border-radius: 0 0 var(--radius-sm) 0;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 0;
}

/* === Header: Glass Morphism === */
body[data-theme] .site-header {
  background: var(--chrome-surface);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: none;
  transition: box-shadow var(--transition-normal);
}

body[data-theme] .site-header.scrolled {
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

body[data-theme] .header-inner {
  max-width: var(--shell-header);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 1.5rem;
}

/* === Logo === */
body[data-theme] .site-logo {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.35rem;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* === Pill Navigation === */
body[data-theme] .main-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

body[data-theme] .main-nav::-webkit-scrollbar {
  display: none;
}

body[data-theme] .main-nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.5rem;
  padding: 0.45rem 0.9rem;
  border: 1px solid transparent;
  border-radius: var(--radius-full);
  color: var(--text-medium);
  font-weight: 700;
  font-size: 0.82rem;
  text-decoration: none;
  white-space: nowrap;
  transition:
    background var(--transition-fast),
    border-color var(--transition-fast),
    box-shadow var(--transition-fast),
    color var(--transition-fast),
    transform var(--transition-fast);
}

body[data-theme] .main-nav a:hover {
  background: var(--link-hover-surface);
  color: var(--text-dark);
  border-color: var(--primary-light);
}

body[data-theme] .main-nav a.active {
  background: var(--active-surface);
  color: var(--text-dark);
  border-color: var(--active-border);
  box-shadow: inset 0 -3px 0 var(--active-border);
  font-weight: 800;
}

/* === Header Actions (Search + Lang Switcher) === */
body[data-theme] .header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

body[data-theme] .search-input {
  padding: 0.5rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-family: var(--font-body);
  background: var(--chrome-surface-strong);
  color: var(--text-dark);
  width: 160px;
  min-height: 2.5rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

body[data-theme] .search-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--link-hover-surface);
  outline: none;
}

body[data-theme] .search-input::placeholder {
  color: var(--text-light);
}

/* === Language Switcher (Pill Style) === */
body[data-theme] .lang-switcher {
  display: flex;
  gap: 0.35rem;
  align-items: center;
}

body[data-theme] .lang-switcher button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.5rem;
  min-height: 2.5rem;
  padding: 0.4rem 0.65rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  background: var(--chrome-surface-strong);
  color: var(--text-medium);
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  transition:
    background var(--transition-fast),
    border-color var(--transition-fast),
    color var(--transition-fast);
}

body[data-theme] .lang-switcher button:hover {
  background: var(--link-hover-surface);
  color: var(--text-dark);
  border-color: var(--primary-light);
}

body[data-theme] .lang-switcher button.active-lang {
  background: var(--active-surface);
  color: var(--text-dark);
  border-color: var(--active-border);
  box-shadow: inset 0 -2px 0 var(--active-border);
  font-weight: 800;
}

/* === Main Content Container === */
body[data-theme] #main-content {
  max-width: var(--shell-main);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-md) var(--space-4xl);
}

/* === Typography === */
body[data-theme] h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.12;
  color: var(--text-dark);
  margin-bottom: var(--space-md);
}

body[data-theme] h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.3;
  color: var(--text-dark);
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
}

body[data-theme] h3 {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-dark);
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
}

body[data-theme] p {
  color: var(--text-medium);
  margin-bottom: var(--space-md);
  line-height: 1.8;
}

body[data-theme] a {
  color: var(--primary-dark);
  text-decoration: none;
  font-weight: 600;
  transition: color var(--transition-fast);
}

body[data-theme] a:hover {
  color: var(--accent-dark);
  text-decoration: underline;
  text-underline-offset: 0.18em;
}

body[data-theme] ul,
body[data-theme] ol {
  color: var(--text-medium);
  padding-left: 1.5rem;
  margin-bottom: var(--space-md);
}

body[data-theme] li {
  margin-bottom: 0.5rem;
}

/* === Hero Section === */
body[data-theme] .hero {
  text-align: center;
  padding: var(--space-3xl) var(--space-md) var(--space-2xl);
  margin-bottom: var(--space-xl);
}

body[data-theme] .hero h1 {
  margin-bottom: var(--space-md);
}

body[data-theme] .hero p {
  font-size: 1.06rem;
  color: var(--text-medium);
  max-width: 700px;
  margin: 0 auto;
}

/* === Card Grid (Homepage / Category) === */
body[data-theme] .card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

body[data-theme] .card {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: 0 8px 24px rgba(93, 78, 96, 0.08);
  transition:
    box-shadow var(--transition-normal),
    border-color var(--transition-normal),
    transform var(--transition-fast);
}

body[data-theme] .card:hover {
  box-shadow: 0 12px 32px var(--shadow);
  border-color: var(--primary-light);
  transform: translateY(-2px);
}

body[data-theme] .card h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  margin: 0;
  color: var(--text-dark);
}

body[data-theme] .card p {
  font-size: 0.9rem;
  color: var(--text-medium);
  margin: 0;
  flex: 1;
}

body[data-theme] .card a {
  display: inline-flex;
  align-items: center;
  align-self: flex-start;
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
  color: var(--text-dark);
  font-size: 0.82rem;
  font-weight: 800;
  text-decoration: none;
  border: 1px solid var(--active-border);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
  transition: transform var(--transition-fast);
  margin-top: auto;
}

body[data-theme] .card a:hover {
  transform: translateY(-1px);
  text-decoration: none;
  color: var(--text-dark);
}

/* === Breadcrumb === */
body[data-theme] .breadcrumb {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: var(--space-md);
}

body[data-theme] .breadcrumb a {
  color: var(--primary-dark);
  font-weight: 700;
  text-decoration: none;
}

body[data-theme] .breadcrumb a:hover {
  text-decoration: underline;
}

/* === Table of Contents === */
body[data-theme] .toc {
  background: var(--surface-muted);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

body[data-theme] .toc h3 {
  font-family: var(--font-display);
  font-size: 1rem;
  margin: 0 0 var(--space-sm);
  color: var(--text-dark);
}

body[data-theme] .toc ol {
  margin: 0;
  padding-left: 1.25rem;
  color: var(--text-medium);
}

body[data-theme] .toc li {
  margin-bottom: 0.35rem;
}

body[data-theme] .toc li:last-child {
  margin-bottom: 0;
}

body[data-theme] .toc a {
  font-size: 0.92rem;
  color: var(--text-medium);
  font-weight: 600;
}

body[data-theme] .toc a:hover {
  color: var(--primary-dark);
}

/* === Article Content === */
body[data-theme] .article-content {
  margin-top: var(--space-lg);
}

body[data-theme] .article-content section {
  margin-bottom: var(--space-xl);
}

body[data-theme] .article-content h2 {
  padding-bottom: var(--space-xs);
  border-bottom: 2px solid var(--primary-light);
}

body[data-theme] .article-content p {
  line-height: 1.85;
}

body[data-theme] .article-content ul,
body[data-theme] .article-content ol {
  line-height: 1.8;
}

/* === Category Description === */
body[data-theme] .category-desc {
  font-size: 1.06rem;
  color: var(--text-medium);
  margin-bottom: var(--space-xl);
}

/* === Section Intro (homepage) === */
body[data-theme] #main-content > section > p {
  color: var(--text-medium);
  font-size: 1rem;
}

/* === Footer === */
body[data-theme] .site-footer {
  margin-top: var(--space-4xl);
  border-top: 1px solid var(--border);
  background: var(--chrome-surface-strong);
}

body[data-theme] .footer-inner {
  max-width: var(--shell-header);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  padding: 1.5rem;
  font-size: 0.875rem;
  color: var(--text-medium);
}

body[data-theme] .footer-links {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
  list-style: none;
  padding: 0;
  margin: 0;
}

body[data-theme] .footer-links a {
  color: var(--text-medium);
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-underline-offset: 0.18em;
}

body[data-theme] .footer-links a:hover {
  color: var(--text-dark);
}

/* === Focus & Accessibility === */
body[data-theme] :where(a, button, input, select, summary, [tabindex]):focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 3px;
}

/* === Responsive: Nav Collapse @ 1120px === */
@media (max-width: 1120px) {
  body[data-theme] .main-nav {
    display: none;
  }

  body[data-theme] .header-actions {
    margin-left: auto;
  }

  body[data-theme] .lang-switcher {
    display: none;
  }

  body[data-theme] .search-input {
    width: 130px;
  }
}

/* === Responsive: Single Column @ 640px === */
@media (max-width: 640px) {
  body[data-theme] .header-inner {
    padding: 0.75rem 1rem;
    flex-wrap: wrap;
  }

  body[data-theme] .header-actions {
    width: 100%;
    justify-content: stretch;
  }

  body[data-theme] .search-input {
    width: 100%;
    flex: 1;
  }

  body[data-theme] #main-content {
    padding: var(--space-md) 1rem var(--space-2xl);
    max-width: 100%;
    min-width: 0;
  }

  body[data-theme] .hero {
    padding: var(--space-xl) var(--space-sm) var(--space-lg);
  }

  body[data-theme] .hero h1 {
    font-size: 1.8rem;
  }

  body[data-theme] .card-grid {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }

  body[data-theme] h1,
  body[data-theme] h2,
  body[data-theme] h3,
  body[data-theme] p,
  body[data-theme] a {
    overflow-wrap: anywhere;
  }

  body[data-theme] .footer-inner {
    flex-direction: column;
    text-align: center;
    padding: 1.25rem 1rem;
  }

  body[data-theme] .footer-links {
    justify-content: center;
  }

  body[data-theme] .article-content h2 {
    font-size: 1.3rem;
  }

  body[data-theme] .toc {
    padding: var(--space-md);
  }
}

/* === Responsive: Mid-range @ 780px === */
@media (max-width: 780px) {
  body[data-theme] .header-inner {
    padding-left: 1rem;
    padding-right: 1rem;
  }
}

/* === Reduced Motion === */
@media (prefers-reduced-motion: reduce) {
  body[data-theme] *,
  body[data-theme] *::before,
  body[data-theme] *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

/* === High Contrast === */
@media (prefers-contrast: more) {
  body[data-theme] {
    --border: var(--text-dark);
    --active-surface: var(--card-bg);
    --link-hover-surface: var(--card-bg);
  }

  body[data-theme] .main-nav a,
  body[data-theme] .lang-switcher button,
  body[data-theme] .search-input,
  body[data-theme] .card,
  body[data-theme] .toc,
  body[data-theme] .footer-links a {
    border-width: 2px;
  }
}

/* === Forced Colors === */
@media (forced-colors: active) {
  body[data-theme] .main-nav a,
  body[data-theme] .lang-switcher button,
  body[data-theme] .search-input,
  body[data-theme] .card a,
  body[data-theme] .footer-links a {
    forced-color-adjust: auto;
    border: 1px solid CanvasText;
  }
}