/* ================================================================
   AXIMORA INSIGHTS - Blog Design System
   Brand: Dark theme + Cyan accent (#00D4FF)
   Fonts: Inter (body), Space Grotesk (headings), Noto Sans SC (中文)
   ================================================================ */

/* ---- CSS Variables ---- */
:root {
  /* Brand Colors */
  --brand-cyan: #00D4FF;
  --brand-cyan-rgb: 0, 212, 255;
  --brand-blue: #0066FF;
  --brand-blue-rgb: 0, 102, 255;
  --brand-gradient: linear-gradient(135deg, #00D4FF, #0066FF);

  /* Dark Theme */
  --bg-primary: #06060a;
  --bg-secondary: #0c0c14;
  --bg-tertiary: #12121e;
  --bg-card: #0f0f1a;
  --bg-card-hover: #161628;
  --bg-overlay: rgba(6, 6, 10, 0.95);

  /* Text */
  --text-primary: #f0f0f5;
  --text-secondary: #a0a0b8;
  --text-muted: #606078;
  --text-accent: var(--brand-cyan);

  /* Borders */
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-light: rgba(255, 255, 255, 0.1);
  --border-accent: rgba(0, 212, 255, 0.3);

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Typography */
  --font-sans: 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
  --font-display: 'Space Grotesk', 'Noto Sans SC', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2rem;
  --text-4xl: 2.5rem;
  --text-5xl: 3.25rem;

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 40px rgba(var(--brand-cyan-rgb), 0.15);

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-fast: 150ms;
  --duration-normal: 300ms;
  --duration-slow: 500ms;

  /* Layout */
  --nav-height: 72px;
  --container-max: 1200px;
  --container-narrow: 800px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  overflow-x: hidden;
}

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

a:hover {
  color: var(--brand-cyan);
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

ul, ol { list-style: none; }

::selection {
  background: rgba(var(--brand-cyan-rgb), 0.3);
  color: var(--text-primary);
}

/* ================================================================
   NAVIGATION
   ================================================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: var(--bg-overlay);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  transition: background var(--duration-normal), border-color var(--duration-normal), box-shadow var(--duration-normal);
}

.nav--scrolled {
  background: rgba(6, 6, 10, 0.95);
  border-bottom-color: var(--border-light);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.nav__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--text-primary);
  text-decoration: none;
}

.nav__logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.nav__logo-primary {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  letter-spacing: -0.02em;
}

.nav__logo-secondary {
  font-size: var(--text-xs);
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav__link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  padding: var(--space-xs) 0;
  position: relative;
  transition: color var(--duration-fast);
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--brand-gradient);
  border-radius: 1px;
  transition: width var(--duration-normal) var(--ease-out);
}

.nav__link:hover,
.nav__link--active {
  color: var(--text-primary);
}

.nav__link--active::after,
.nav__link:hover::after {
  width: 100%;
}

.nav__actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.nav__search-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  transition: all var(--duration-fast);
}

.nav__search-btn:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.05);
}

.nav__lang-btn {
  display: flex;
  align-items: center;
  gap: 2px;
  padding: 6px 12px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-light);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-secondary);
  transition: all var(--duration-fast);
}

.nav__lang-current {
  color: var(--brand-cyan);
}

.nav__lang-divider {
  opacity: 0.3;
}

.nav__lang-btn:hover {
  border-color: var(--border-accent);
  background: rgba(var(--brand-cyan-rgb), 0.05);
}

/* Mobile Menu Button */
.nav__mobile-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 24px;
  padding: 4px 0;
}

.nav__mobile-btn span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 1px;
  transition: all var(--duration-normal);
}

.nav__mobile-btn--active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav__mobile-btn--active span:nth-child(2) {
  opacity: 0;
}
.nav__mobile-btn--active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Search Overlay */
.search-overlay {
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  height: calc(100vh - var(--nav-height));
  background: var(--bg-primary);
  padding: var(--space-xl);
  overflow-y: auto;
  transform: translateY(-100%);
  opacity: 0;
  pointer-events: none;
  transition: all var(--duration-normal) var(--ease-out);
  z-index: 999;
}

.search-overlay--active {
  transform: translateY(0);
  opacity: 1;
  pointer-events: all;
}

.search-overlay__container {
  max-width: var(--container-narrow);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.search-overlay__input {
  flex: 1;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  font-size: var(--text-lg);
  color: var(--text-primary);
  font-family: var(--font-sans);
  outline: none;
  transition: border-color var(--duration-fast);
}

.search-overlay__input:focus {
  border-color: var(--brand-cyan);
}

.search-overlay__input::placeholder {
  color: var(--text-muted);
}

.search-overlay__close {
  font-size: var(--text-2xl);
  color: var(--text-muted);
  padding: var(--space-sm);
  line-height: 1;
}

.search-overlay__results {
  max-width: var(--container-narrow);
  margin: var(--space-lg) auto 0;
  max-height: 400px;
  overflow-y: auto;
}

.search-result {
  display: block;
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  text-decoration: none;
  transition: background var(--duration-fast);
}

.search-result:hover {
  background: var(--bg-card-hover);
}

.search-result__category {
  font-size: var(--text-xs);
  color: var(--brand-cyan);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.search-result__title {
  font-weight: 600;
  margin-top: 2px;
}

.search-result__excerpt {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-top: 2px;
}

/* ================================================================
   MAIN LAYOUT
   ================================================================ */
.main {
  padding-top: var(--nav-height);
  min-height: 100vh;
}

.view--hidden {
  display: none;
}

.section {
  padding: var(--space-4xl) 0;
}

.section--alt {
  background: var(--bg-secondary);
}

.section__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.section__header {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.section__label {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--brand-cyan);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: var(--space-sm);
}

.section__title {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.section__desc {
  font-size: var(--text-lg);
  color: var(--text-secondary);
  margin-top: var(--space-md);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ================================================================
   HERO
   ================================================================ */
.hero {
  position: relative;
  padding: var(--space-4xl) 0;
  min-height: 85vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 30%, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 80% 80% at 50% 30%, black 30%, transparent 80%);
}

.hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.15;
}

.hero__glow--1 {
  width: 600px;
  height: 600px;
  background: var(--brand-cyan);
  top: -200px;
  right: -100px;
  animation: heroGlow1 8s ease-in-out infinite alternate;
}

.hero__glow--2 {
  width: 400px;
  height: 400px;
  background: var(--brand-blue);
  bottom: -100px;
  left: -50px;
  animation: heroGlow2 10s ease-in-out infinite alternate;
}

@keyframes heroGlow1 {
  0% { transform: translate(0, 0) scale(1); opacity: 0.15; }
  100% { transform: translate(-40px, 30px) scale(1.1); opacity: 0.2; }
}

@keyframes heroGlow2 {
  0% { transform: translate(0, 0) scale(1); opacity: 0.1; }
  100% { transform: translate(30px, -20px) scale(1.15); opacity: 0.15; }
}

.hero__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  background:
    linear-gradient(var(--bg-primary), var(--bg-primary)) padding-box,
    linear-gradient(135deg, var(--brand-cyan), var(--brand-blue), var(--brand-cyan)) border-box;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--brand-cyan);
  letter-spacing: 0.08em;
  margin-bottom: var(--space-xl);
}

.hero__badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brand-cyan);
  box-shadow: 0 0 6px var(--brand-cyan);
  animation: badgePulse 2.5s ease-in-out infinite;
}

@keyframes badgePulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 6px var(--brand-cyan); }
  50% { opacity: 0.4; box-shadow: 0 0 2px var(--brand-cyan); }
}

.hero__title {
  font-family: var(--font-display);
  font-size: var(--text-5xl);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.04em;
  margin-bottom: var(--space-xl);
}

.hero__title-accent {
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__subtitle {
  font-size: var(--text-lg);
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto var(--space-2xl);
  line-height: 1.8;
}

.hero__stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2xl);
  margin-bottom: var(--space-2xl);
}

.hero__stat {
  text-align: center;
}

.hero__stat-number {
  display: block;
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.hero__stat-label {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.hero__stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border-light);
}

.hero__cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
}

/* ================================================================
   BUTTONS
   ================================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 28px;
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  text-decoration: none;
  white-space: nowrap;
}

.btn--primary {
  background: var(--brand-gradient);
  color: #000;
  border-color: transparent;
}

.btn--primary:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-glow);
  color: #000;
}

.btn--ghost {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border-light);
}

.btn--ghost:hover {
  color: var(--text-primary);
  border-color: var(--text-secondary);
  background: rgba(255,255,255,0.03);
}

.btn--sm {
  padding: 8px 16px;
  font-size: var(--text-xs);
}

.btn--lg {
  padding: 16px 36px;
  font-size: var(--text-base);
}

/* ================================================================
   FEATURED GRID
   ================================================================ */
.featured-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
}

.featured-card {
  position: relative;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  overflow: hidden;
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  text-decoration: none;
  color: inherit;
}

.featured-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  color: inherit;
}

.featured-card__image {
  height: 220px;
  background: var(--bg-tertiary);
  position: relative;
  overflow: hidden;
}

.featured-card__image-bg {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.featured-card__pattern {
  position: absolute;
  inset: 0;
  opacity: 0.5;
}

.featured-card__icon-wrap {
  position: relative;
  z-index: 1;
  width: 64px;
  height: 64px;
  border-radius: var(--radius-lg);
  background: rgba(var(--brand-cyan-rgb), 0.1);
  border: 1px solid rgba(var(--brand-cyan-rgb), 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
}

.featured-card__body {
  padding: var(--space-xl);
}

.featured-card__category {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--brand-cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-sm);
}

.featured-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: var(--space-md);
  letter-spacing: -0.01em;
}

.featured-card__excerpt {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.featured-card__meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-sm);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

.featured-card__date {
  color: var(--text-muted);
}

.featured-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-top: var(--space-md);
}

.featured-card__gradient {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(var(--brand-cyan-rgb), 0.15), rgba(0, 102, 255, 0.1));
}

.featured-card__icon {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 64px;
  height: 64px;
  border-radius: var(--radius-lg);
  background: rgba(var(--brand-cyan-rgb), 0.1);
  border: 1px solid rgba(var(--brand-cyan-rgb), 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--brand-cyan);
}

.featured-card__icon svg {
  width: 28px;
  height: 28px;
}

.featured-card:first-child {
  grid-row: span 2;
}

.featured-card:first-child .featured-card__image {
  height: 300px;
}

.featured-card:first-child .featured-card__title {
  font-size: var(--text-2xl);
}

/* Shared tag pill style */
.tag {
  display: inline-block;
  font-size: 11px;
  padding: 2px 10px;
  border-radius: var(--radius-full);
  background: rgba(var(--brand-cyan-rgb), 0.06);
  color: var(--text-muted);
  border: 1px solid var(--border-subtle);
  line-height: 1.6;
}

/* ================================================================
   CATEGORY GRID
   ================================================================ */
.category-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.category-card {
  padding: var(--space-2xl);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  text-decoration: none;
  color: inherit;
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--brand-gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--duration-normal) var(--ease-out);
}

.category-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  color: inherit;
}

.category-card:hover::before {
  transform: scaleX(1);
}

.category-card__icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: rgba(var(--brand-cyan-rgb), 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-lg);
  color: var(--brand-cyan);
}

.category-card__label {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--brand-cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-xs);
}

.category-card__name {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.category-card__desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-lg);
}

.category-card__count {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.category-card__count strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* ================================================================
   ARTICLE LIST / GRID
   ================================================================ */
.article-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.article-card {
  display: flex;
  gap: var(--space-lg);
  padding: var(--space-xl);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  text-decoration: none;
  color: inherit;
}

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

.article-card__number {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: rgba(var(--brand-cyan-rgb), 0.15);
  line-height: 1;
  min-width: 48px;
  flex-shrink: 0;
}

.article-card__body {
  flex: 1;
  min-width: 0;
}

.article-card__category {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--brand-cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-xs);
}

.article-card__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: var(--space-sm);
}

.article-card__excerpt {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-top: var(--space-md);
}

.article-card__tag {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: rgba(var(--brand-cyan-rgb), 0.06);
  color: var(--text-muted);
  border: 1px solid var(--border-subtle);
}

/* Article Grid (categories page) */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.article-grid .article-card {
  flex-direction: column;
}

.article-grid .article-card__number {
  font-size: var(--text-2xl);
}

/* Filter Tabs */
.filter-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--border-subtle);
}

.filter-tab {
  padding: 8px 20px;
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
  background: transparent;
  transition: all var(--duration-fast);
}

.filter-tab:hover {
  color: var(--text-primary);
  border-color: var(--border-light);
}

.filter-tab--active {
  color: #000;
  background: var(--brand-gradient);
  border-color: transparent;
  font-weight: 600;
}

/* ================================================================
   CTA SECTION
   ================================================================ */
.cta-section {
  padding: var(--space-3xl) 0 var(--space-4xl);
}

.cta-card {
  position: relative;
  padding: var(--space-4xl);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-accent);
  background: var(--bg-card);
  text-align: center;
  overflow: hidden;
}

.cta-card__glow {
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 400px;
  height: 200px;
  background: var(--brand-cyan);
  filter: blur(120px);
  opacity: 0.08;
  pointer-events: none;
}

.cta-card__content {
  position: relative;
  z-index: 1;
}

.cta-card__title {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.cta-card__desc {
  font-size: var(--text-lg);
  color: var(--text-secondary);
  margin-bottom: var(--space-2xl);
}

.cta-card__steps {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.cta-card__step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
}

.cta-card__step-num {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.cta-card__step-text {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.cta-card__step-arrow {
  color: var(--text-muted);
}

/* ================================================================
   PAGE HEADER
   ================================================================ */
.page-header {
  padding: var(--space-3xl) 0 var(--space-xl);
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
}

.page-header__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.page-header__breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-bottom: var(--space-lg);
}

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

.page-header__breadcrumb a:hover {
  color: var(--brand-cyan);
}

.page-header__title {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: 700;
  letter-spacing: -0.03em;
}

/* ================================================================
   ARTICLE PAGE
   ================================================================ */
.article-page__header {
  padding: var(--space-3xl) 0 var(--space-2xl);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-subtle);
}

.article-page__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.article-page__breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-bottom: var(--space-xl);
}

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

.article-page__breadcrumb a:hover {
  color: var(--brand-cyan);
}

.article-page__meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.article-page__category {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  background: rgba(var(--brand-cyan-rgb), 0.1);
  color: var(--brand-cyan);
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.article-page__date,
.article-page__reading {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.article-page__title {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-xl);
  max-width: 800px;
}

.article-page__tldr {
  padding: 1.5rem 1.75rem;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(var(--brand-cyan-rgb), 0.05) 0%, rgba(var(--brand-blue-rgb), 0.04) 100%);
  border: 1px solid rgba(var(--brand-cyan-rgb), 0.12);
  border-left: 3px solid var(--brand-cyan);
  font-size: var(--text-base);
  color: var(--text-secondary);
  line-height: 1.85;
  margin-top: var(--space-xl);
}

.article-page__tldr .tldr-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 0.75rem;
  color: var(--brand-cyan);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.article-page__tldr .tldr-header svg {
  flex-shrink: 0;
  opacity: 0.85;
}

.article-page__tldr p {
  margin: 0;
}

/* Article Body */
.article-page__body {
  padding: var(--space-3xl) 0;
}

.article-page__body > .article-page__container {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: var(--space-3xl);
  align-items: start;
}

/* ---- Article Content: Premium Typography ---- */
.article-page__content {
  min-width: 0;
  max-width: 740px;
  font-size: 1.0625rem;
  line-height: 1.9;
  color: var(--text-secondary);
}

/* First paragraph — lead style */
.article-page__content > p:first-child {
  font-size: 1.15rem;
  line-height: 1.85;
  color: var(--text-primary);
  opacity: 0.92;
}

/* ---- Headings ---- */
.article-page__content h2 {
  font-family: var(--font-display);
  font-size: 1.625rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 3.5rem;
  margin-bottom: 1.25rem;
  padding-top: 0.5rem;
  padding-bottom: 0.75rem;
  letter-spacing: -0.02em;
  border-bottom: none;
  position: relative;
}

.article-page__content h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--brand-gradient);
  border-radius: 2px;
}

.article-page__content h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 2.5rem;
  margin-bottom: 0.875rem;
  padding-left: 0.875rem;
  border-left: 3px solid rgba(var(--brand-cyan-rgb), 0.4);
}

.article-page__content h4 {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 2rem;
  margin-bottom: 0.625rem;
  text-transform: none;
  letter-spacing: 0;
}

/* ---- Body text ---- */
.article-page__content p {
  margin-bottom: 1.375rem;
  color: var(--text-secondary);
  word-break: break-word;
}

.article-page__content strong {
  color: var(--text-primary);
  font-weight: 650;
}

.article-page__content em {
  color: var(--text-secondary);
  font-style: italic;
}

.article-page__content a {
  color: var(--brand-cyan);
  text-decoration: underline;
  text-decoration-color: rgba(var(--brand-cyan-rgb), 0.3);
  text-underline-offset: 3px;
  transition: text-decoration-color var(--duration-fast);
}

.article-page__content a:hover {
  text-decoration-color: var(--brand-cyan);
}

/* ---- Lists ---- */
.article-page__content ul,
.article-page__content ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.article-page__content ul {
  list-style: none;
}

.article-page__content ul > li {
  position: relative;
  padding-left: 0.25rem;
  margin-bottom: 0.625rem;
  color: var(--text-secondary);
}

.article-page__content ul > li::before {
  content: '';
  position: absolute;
  left: -1.25rem;
  top: 0.6em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brand-cyan);
  opacity: 0.7;
}

.article-page__content ol > li {
  margin-bottom: 0.625rem;
  color: var(--text-secondary);
  padding-left: 0.25rem;
}

.article-page__content ol > li::marker {
  color: var(--brand-cyan);
  font-weight: 600;
  font-family: var(--font-display);
}

.article-page__content li > ul,
.article-page__content li > ol {
  margin-top: 0.5rem;
  margin-bottom: 0.5rem;
}

/* ---- Blockquotes ---- */
.article-page__content blockquote {
  margin: 2rem 0;
  padding: 1.25rem 1.5rem;
  border-left: 3px solid;
  border-image: var(--brand-gradient) 1;
  background: rgba(var(--brand-cyan-rgb), 0.03);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: italic;
  color: var(--text-secondary);
  position: relative;
}

.article-page__content blockquote p {
  margin-bottom: 0.5rem;
}

.article-page__content blockquote p:last-child {
  margin-bottom: 0;
}

/* ---- Code ---- */
.article-page__content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  padding: 2px 7px;
  border-radius: 4px;
  background: rgba(var(--brand-cyan-rgb), 0.08);
  color: var(--brand-cyan);
  border: 1px solid rgba(var(--brand-cyan-rgb), 0.12);
}

.article-page__content pre {
  margin: 2rem 0;
  padding: 1.5rem;
  border-radius: var(--radius-md);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  overflow-x: auto;
  line-height: 1.65;
}

.article-page__content pre code {
  padding: 0;
  background: none;
  border: none;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* ---- Tables ---- */
.article-table-wrapper {
  margin: 2rem 0;
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  -webkit-overflow-scrolling: touch;
}

.article-page__content table {
  width: 100%;
  margin: 0;
  border-collapse: collapse;
  font-size: 0.875rem;
  line-height: 1.6;
}

.article-page__content th {
  padding: 0.875rem 1rem;
  background: rgba(var(--brand-cyan-rgb), 0.06);
  font-weight: 600;
  color: var(--text-primary);
  text-align: left;
  white-space: nowrap;
  border-bottom: 2px solid rgba(var(--brand-cyan-rgb), 0.15);
}

.article-page__content td {
  padding: 0.75rem 1rem;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-subtle);
  text-align: left;
  vertical-align: top;
}

.article-page__content th,
.article-page__content td {
  border-right: none;
  border-left: none;
}

.article-page__content tbody tr:hover {
  background: rgba(var(--brand-cyan-rgb), 0.02);
}

.article-page__content tbody tr:last-child td {
  border-bottom: none;
}

/* ---- Horizontal Rules — Section Dividers ---- */
.article-page__content hr {
  border: none;
  margin: 3rem 0;
  height: 1px;
  background: linear-gradient(90deg,
    transparent 0%,
    var(--border-light) 20%,
    var(--border-light) 80%,
    transparent 100%
  );
  position: relative;
}

/* ---- Checkbox / Checklist items ---- */
.article-page__content .checklist-item {
  list-style: none;
  display: flex;
  align-items: flex-start;
  gap: 0.625rem;
  padding: 0.5rem 0.75rem;
  margin-left: -0.75rem;
  border-radius: var(--radius-sm);
  transition: background var(--duration-fast);
}

.article-page__content .checklist-item:hover {
  background: rgba(var(--brand-cyan-rgb), 0.03);
}

.article-page__content .checklist-item::before {
  display: none;
}

.article-page__content .checklist-item input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  min-width: 18px;
  border: 2px solid var(--border-light);
  border-radius: 4px;
  margin-top: 2px;
  cursor: pointer;
  transition: all var(--duration-fast);
  position: relative;
}

.article-page__content .checklist-item input[type="checkbox"]:checked {
  background: var(--brand-cyan);
  border-color: var(--brand-cyan);
}

.article-page__content .checklist-item input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  left: 4px;
  top: 1px;
  width: 5px;
  height: 9px;
  border: 2px solid var(--bg-primary);
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

/* ---- Images ---- */
.article-page__content img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  margin: 1.5rem 0;
}

/* Sidebar */
.article-page__sidebar {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-xl));
}

.sidebar-toc {
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  margin-bottom: var(--space-lg);
}

.sidebar-toc__title {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-md);
}

.sidebar-toc__nav a {
  display: block;
  padding: var(--space-xs) 0;
  font-size: var(--text-sm);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--duration-fast);
  border-left: 2px solid transparent;
  padding-left: var(--space-md);
}

.sidebar-toc__nav a:hover,
.sidebar-toc__link--active {
  color: var(--brand-cyan);
  border-left-color: var(--brand-cyan);
}

.sidebar-author {
  padding: var(--space-xl);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  text-align: center;
}

.sidebar-author__avatar {
  margin-bottom: var(--space-md);
}

.sidebar-author__avatar img {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
}

.sidebar-author__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
}

.sidebar-author__role {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-bottom: var(--space-lg);
}

/* Related Articles */
.article-page__related {
  padding: var(--space-3xl) 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

/* ================================================================
   ABOUT PAGE
   ================================================================ */
.about {
  padding: var(--space-3xl) 0 var(--space-4xl);
}

.about__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.about__hero {
  display: flex;
  gap: var(--space-3xl);
  align-items: flex-start;
  padding-bottom: var(--space-3xl);
  border-bottom: 1px solid var(--border-subtle);
}

.about__avatar {
  flex-shrink: 0;
}

.about__avatar img {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
  border: 3px solid var(--brand-cyan);
}

.about__name {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.about__name-cn {
  font-size: var(--text-2xl);
  color: var(--text-muted);
  font-weight: 400;
}

.about__tagline {
  font-size: var(--text-lg);
  color: var(--brand-cyan);
  margin-bottom: var(--space-lg);
}

.about__bio {
  font-size: var(--text-base);
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-xl);
  max-width: 600px;
}

.about__links {
  display: flex;
  gap: var(--space-md);
}

/* About Stats */
.about__stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  padding: var(--space-3xl) 0;
}

.about__stat-card {
  text-align: center;
  padding: var(--space-xl);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
}

.about__stat-icon {
  color: var(--brand-cyan);
  margin-bottom: var(--space-md);
}

.about__stat-number {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
}

.about__stat-text {
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin-top: var(--space-xs);
}

.about__section {
  padding: var(--space-3xl) 0;
  border-bottom: 1px solid var(--border-subtle);
}

.about__section:last-child {
  border-bottom: none;
}

.about__section-title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 700;
  margin-bottom: var(--space-2xl);
}

/* Expertise Grid */
.expertise-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.expertise-card {
  padding: var(--space-xl);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
}

.expertise-card__icon {
  margin-bottom: var(--space-lg);
}

.expertise-card h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.expertise-card p {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: var(--space-2xl);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border-light);
}

.timeline__item {
  position: relative;
  padding-bottom: var(--space-2xl);
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__marker {
  position: absolute;
  left: calc(-1 * var(--space-2xl) + 3px);
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--brand-cyan);
  border: 2px solid var(--bg-primary);
}

.timeline__date {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--brand-cyan);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-xs);
}

.timeline__content h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.timeline__role {
  font-size: var(--text-sm);
  color: var(--text-muted);
  font-weight: 400;
}

.timeline__content p {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Framework Grid */
.framework-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
}

.framework-card {
  padding: var(--space-xl);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
}

.framework-card__name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--brand-cyan);
  margin-bottom: var(--space-sm);
}

.framework-card__desc {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ================================================================
   FOOTER
   ================================================================ */
.footer {
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
  padding: var(--space-4xl) 0 var(--space-2xl);
}

.footer__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-3xl);
  padding-bottom: var(--space-3xl);
  border-bottom: 1px solid var(--border-subtle);
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  color: var(--text-primary);
  margin-bottom: var(--space-md);
}

.footer__desc {
  font-size: var(--text-sm);
  color: var(--text-muted);
  line-height: 1.6;
}

.footer__col h4 {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
}

.footer__col a {
  display: block;
  font-size: var(--text-sm);
  color: var(--text-muted);
  padding: var(--space-xs) 0;
  transition: color var(--duration-fast);
  text-decoration: none;
}

.footer__col a:hover {
  color: var(--brand-cyan);
}

.footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-xl);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* ================================================================
   RESPONSIVE
   ================================================================ */
@media (max-width: 1024px) {
  .featured-grid {
    grid-template-columns: 1fr;
  }
  .featured-card:first-child {
    grid-row: auto;
  }

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

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

  .article-page__body > .article-page__container {
    grid-template-columns: 1fr;
  }

  .article-page__sidebar {
    position: static;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
  }

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

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

@media (max-width: 768px) {
  :root {
    --text-5xl: 2.25rem;
    --text-4xl: 2rem;
    --text-3xl: 1.5rem;
    --space-4xl: 3rem;
    --space-3xl: 2rem;
  }

  .nav__links {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    height: calc(100vh - var(--nav-height));
    z-index: 999;
    background: rgba(6, 6, 10, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-2xl);
  }

  .nav__links--open {
    display: flex;
  }

  .nav__link {
    font-size: var(--text-xl);
  }

  .nav__mobile-btn {
    display: flex;
  }

  .hero {
    min-height: auto;
    padding: var(--space-3xl) 0;
  }

  .hero__stats {
    gap: var(--space-lg);
  }

  .hero__cta {
    flex-direction: column;
  }

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

  .article-list {
    grid-template-columns: 1fr;
  }

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

  .article-card {
    flex-direction: column;
  }

  .article-page__sidebar {
    grid-template-columns: 1fr;
  }

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

  .about__hero {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .about__bio {
    margin-left: auto;
    margin-right: auto;
  }

  .about__links {
    justify-content: center;
  }

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

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

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

  .cta-card {
    padding: var(--space-2xl);
  }

  .cta-card__steps {
    flex-direction: column;
    gap: var(--space-md);
  }

  .cta-card__step-arrow {
    transform: rotate(90deg);
  }

  .footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }

  .footer__bottom {
    flex-direction: column;
    gap: var(--space-sm);
    text-align: center;
  }
}

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

.animate-in {
  animation: fadeInUp 0.6s var(--ease-out) forwards;
}

/* Scroll-triggered animation */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.6s var(--ease-out);
}

.reveal--visible {
  opacity: 1;
  transform: translateY(0);
}

/* Loading state */
.skeleton {
  background: linear-gradient(90deg,
    var(--bg-tertiary) 25%,
    var(--bg-card-hover) 50%,
    var(--bg-tertiary) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
  border-radius: var(--radius-sm);
}

@keyframes skeleton-loading {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* Back to top */
.back-to-top {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: all var(--duration-normal);
  z-index: 100;
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: all;
}

.back-to-top:hover {
  color: var(--brand-cyan);
  border-color: var(--border-accent);
  transform: translateY(-2px);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border-light);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* ---- Utility classes ---- */
body.no-scroll {
  overflow: hidden;
}

/* ---- Article card header/footer (JS-generated) ---- */
.article-card__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-sm);
}

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

.article-card__footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--space-md);
}

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

/* ---- Search overlay empty state ---- */
.search-overlay__empty {
  text-align: center;
  padding: var(--space-2xl);
  color: var(--text-muted);
  font-size: var(--text-sm);
}

/* ---- Article content components (generated by JS) ---- */

/* Fit / Not-Fit box */
.article-fit-box {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  margin: var(--space-lg) 0 var(--space-2xl);
}

.article-fit-box__yes,
.article-fit-box__no {
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.article-fit-box__yes {
  background: rgba(52, 211, 153, 0.04);
  border-color: rgba(52, 211, 153, 0.2);
}

.article-fit-box__no {
  background: rgba(239, 68, 68, 0.04);
  border-color: rgba(239, 68, 68, 0.2);
}

.article-fit-box h4 {
  font-size: var(--text-base);
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.article-fit-box ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.article-fit-box li {
  padding: var(--space-xs) 0;
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.6;
}

.article-fit-box li::before {
  content: '—';
  margin-right: var(--space-xs);
  color: var(--text-muted);
}

/* Framework highlight */
.article-framework-highlight {
  padding: var(--space-lg) var(--space-xl);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--brand-cyan);
  background: rgba(var(--brand-cyan-rgb), 0.04);
  margin: var(--space-lg) 0;
}

.article-framework-highlight__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--brand-cyan);
  margin-bottom: var(--space-xs);
}

.article-framework-highlight p {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin: 0;
}

/* Checklist */
.article-checklist {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin: var(--space-lg) 0 var(--space-2xl);
}

.article-checklist__item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  cursor: pointer;
  transition: all var(--duration-fast);
}

.article-checklist__item:hover {
  border-color: var(--border-accent);
}

.article-checklist__item input[type="checkbox"] {
  accent-color: var(--brand-cyan);
  margin-top: 3px;
  flex-shrink: 0;
}

.article-checklist__item span {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.5;
}

/* FAQ */
.article-faq {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin: var(--space-lg) 0 var(--space-2xl);
}

.article-faq__item {
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: var(--bg-card);
  overflow: hidden;
  transition: border-color var(--duration-fast);
}

.article-faq__item:hover {
  border-color: var(--border-accent);
}

.article-faq__item summary {
  padding: var(--space-md) var(--space-lg);
  font-size: var(--text-base);
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--text-primary);
}

.article-faq__item summary::before {
  content: '+';
  font-size: var(--text-xl);
  font-weight: 300;
  color: var(--brand-cyan);
  flex-shrink: 0;
  width: 20px;
  text-align: center;
  transition: transform var(--duration-fast);
}

.article-faq__item[open] summary::before {
  content: '−';
}

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

.article-faq__item p {
  padding: 0 var(--space-lg) var(--space-lg) calc(var(--space-lg) + 28px);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0;
}

/* CTA Steps */
/* ---- CTA Steps (premium) ---- */
.article-cta-steps {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  margin: var(--space-lg) 0;
}

.article-cta-step {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  transition: all var(--duration-fast);
}

.article-cta-step:hover {
  border-color: var(--border-accent);
  transform: translateX(4px);
}

.article-cta-step__num {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--brand-cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  min-width: 52px;
  flex-shrink: 0;
}

.article-cta-step span:last-child {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

/* Disclaimer & Updated */
.article-disclaimer {
  font-size: var(--text-xs);
  color: var(--text-muted);
  margin-top: var(--space-xl);
}

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

/* Category color accents */
.cat-A { color: #f59e0b; }
.cat-B { color: #3b82f6; }
.cat-C { color: #10b981; }
.cat-D { color: #ef4444; }
.cat-E { color: #8b5cf6; }
.cat-F { color: var(--brand-cyan); }

/* ---- Responsive additions for new components ---- */
@media (max-width: 768px) {
  .article-fit-box {
    grid-template-columns: 1fr;
  }

  .article-cta-step {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-xs);
  }
}

/* Print styles */
@media print {
  .nav, .footer, .cta-section, .article-page__sidebar {
    display: none;
  }
  body {
    background: white;
    color: black;
  }
  .article-page__body > .article-page__container {
    grid-template-columns: 1fr;
  }
}