/* ============================================
   OpenNHP Official Website Styles
   Theme: Dark Forest - AI Era Security
   ============================================ */

/* ============================================
   CSS Variables
   ============================================ */
:root {
  /* Primary Colors - Dark Forest Theme */
  --bg-primary: #0a0e17;
  --bg-secondary: #0d1321;
  --bg-tertiary: #131a2b;
  --bg-card: rgba(19, 26, 43, 0.8);
  
  /* Accent Colors */
  --accent-primary: #00ff9d;
  --accent-secondary: #00d4aa;
  --accent-tertiary: #7c3aed;
  --accent-glow: rgba(0, 255, 157, 0.3);
  
  /* Text Colors */
  --text-primary: #e8edf5;
  --text-secondary: #a0aec0;
  --text-muted: #64748b;
  
  /* Gradients */
  --gradient-hero: linear-gradient(135deg, #0a0e17 0%, #1a1f3c 50%, #0d1321 100%);
  --gradient-accent: linear-gradient(135deg, #00ff9d 0%, #00d4aa 50%, #7c3aed 100%);
  --gradient-card: linear-gradient(145deg, rgba(19, 26, 43, 0.9) 0%, rgba(10, 14, 23, 0.9) 100%);
  
  /* Borders */
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-accent: rgba(0, 255, 157, 0.3);
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(0, 255, 157, 0.2);
  
  /* Typography */
  --font-heading: 'Outfit', 'Inter', system-ui, sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 5rem;
  
  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
  
  /* Container */
  --container-max: 1280px;
  --container-narrow: 900px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: 1.25rem; }

p {
  margin-bottom: var(--spacing-sm);
}

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

.text-mono {
  font-family: var(--font-mono);
}

/* ============================================
   Layout & Container
   ============================================ */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.section {
  padding: var(--spacing-2xl) 0;
}

.section--hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
}

/* ============================================
   Background Effects
   ============================================ */
.bg-grid {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  opacity: 0.03;
  background-image: 
    linear-gradient(rgba(255, 255, 255, 0.1) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.1) 1px, transparent 1px);
  background-size: 60px 60px;
}

.bg-gradient-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -2;
  background: 
    radial-gradient(ellipse at 20% 20%, rgba(124, 58, 237, 0.15) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(0, 255, 157, 0.08) 0%, transparent 50%),
    var(--bg-primary);
}

/* Animated particles */
.particles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  overflow: hidden;
}

.particle {
  position: absolute;
  width: 4px;
  height: 4px;
  background: var(--accent-primary);
  border-radius: 50%;
  opacity: 0.3;
  animation: float 20s infinite ease-in-out;
}

@keyframes float {
  0%, 100% { transform: translateY(100vh) rotate(0deg); opacity: 0; }
  10% { opacity: 0.3; }
  90% { opacity: 0.3; }
  100% { transform: translateY(-100vh) rotate(720deg); opacity: 0; }
}

/* ============================================
   Navigation
   ============================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--spacing-sm) 0;
  background: rgba(10, 14, 23, 0.8);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  transition: all var(--transition-base);
}

.nav--scrolled {
  padding: var(--spacing-xs) 0;
  background: rgba(10, 14, 23, 0.95);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}

.nav__logo-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-accent);
  border-radius: var(--radius-sm);
  font-size: 1.2rem;
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  list-style: none;
}

.nav__link {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

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

.nav__cta {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.nav__toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: 0.75rem 1.5rem;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn--primary {
  background: var(--gradient-accent);
  color: var(--bg-primary);
  box-shadow: var(--shadow-glow);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 40px rgba(0, 255, 157, 0.4);
  color: var(--bg-primary);
}

.btn--secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
}

.btn--secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--border-accent);
  color: var(--text-primary);
}

.btn--outline {
  background: transparent;
  color: var(--accent-primary);
  border: 1px solid var(--accent-primary);
}

.btn--outline:hover {
  background: var(--accent-primary);
  color: var(--bg-primary);
}

.btn--sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.btn--lg {
  padding: 1rem 2rem;
  font-size: 1.1rem;
}

.btn--icon {
  padding: 0.75rem;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  text-align: center;
  padding-top: 40px;
}

.hero__badges {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-lg);
  animation: fadeInUp 0.6s ease-out;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: 0.5rem 1rem;
  background: rgba(124, 58, 237, 0.15);
  border: 1px solid rgba(124, 58, 237, 0.3);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  color: var(--accent-tertiary);
}

.hero__badge::before {
  content: '';
  width: 8px;
  height: 8px;
  background: var(--accent-tertiary);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.hero__title {
  margin-bottom: var(--spacing-md);
  animation: fadeInUp 0.6s ease-out 0.1s backwards;
}

.hero__subtitle {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto var(--spacing-lg);
  animation: fadeInUp 0.6s ease-out 0.2s backwards;
}

.hero__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-xl);
  animation: fadeInUp 0.6s ease-out 0.3s backwards;
}

.hero__stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xl);
  flex-wrap: wrap;
  animation: fadeInUp 0.6s ease-out 0.4s backwards;
}

.hero__stat {
  text-align: center;
}

.hero__stat-value {
  display: block;
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-primary);
}

.hero__stat-label {
  font-size: 0.875rem;
  color: var(--text-muted);
}

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

/* ============================================
   Cards
   ============================================ */
.card {
  background: var(--gradient-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all var(--transition-base);
}

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

.card__icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 255, 157, 0.1);
  border-radius: var(--radius-md);
  font-size: 1.5rem;
  margin-bottom: var(--spacing-md);
}

.card__title {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-xs);
}

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

.card__link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-md);
  font-weight: 500;
}

.card__link svg {
  transition: transform var(--transition-fast);
}

.card__link:hover svg {
  transform: translateX(4px);
}

/* ============================================
   Features Grid
   ============================================ */
.features {
  padding: var(--spacing-2xl) 0;
}

.features__header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

/* ============================================
   Section Headers
   ============================================ */
.section-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-header__label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--accent-primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--spacing-sm);
}

.section-header__title {
  margin-bottom: var(--spacing-sm);
}

.section-header__desc {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================
   Comparison Table
   ============================================ */
.comparison {
  overflow-x: auto;
  margin: var(--spacing-xl) 0;
}

.comparison table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.comparison th,
.comparison td {
  padding: var(--spacing-sm) var(--spacing-md);
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
}

.comparison th {
  background: var(--bg-tertiary);
  font-weight: 600;
  color: var(--text-primary);
}

.comparison th:first-child {
  border-radius: var(--radius-md) 0 0 0;
}

.comparison th:last-child {
  border-radius: 0 var(--radius-md) 0 0;
}

.comparison td {
  color: var(--text-secondary);
}

.comparison tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.comparison .highlight {
  color: var(--accent-primary);
  font-weight: 500;
}

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

.timeline::before {
  content: '';
  position: absolute;
  left: 15px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--gradient-accent);
}

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

.timeline__item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--spacing-xl) + 8px);
  top: 0;
  width: 16px;
  height: 16px;
  background: var(--accent-primary);
  border-radius: 50%;
  box-shadow: 0 0 20px var(--accent-glow);
}

.timeline__label {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--accent-primary);
  margin-bottom: var(--spacing-xs);
}

.timeline__title {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-xs);
}

.timeline__desc {
  color: var(--text-secondary);
}

/* ============================================
   Ecosystem Cards
   ============================================ */
.ecosystem {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-lg);
}

.ecosystem-card {
  background: var(--gradient-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  transition: all var(--transition-base);
}

.ecosystem-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-4px);
}

.ecosystem-card__header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.ecosystem-card__icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 255, 157, 0.1);
  border-radius: var(--radius-md);
  font-size: 1.5rem;
}

.ecosystem-card__title {
  font-size: 1.25rem;
}

.ecosystem-card__subtitle {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.ecosystem-card__desc {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

.ecosystem-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
}

.tag {
  display: inline-flex;
  padding: 0.25rem 0.75rem;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.tag--accent {
  background: rgba(0, 255, 157, 0.1);
  color: var(--accent-primary);
}

/* ============================================
   Research Papers
   ============================================ */
.papers {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.paper {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: var(--gradient-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

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

.paper__icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(124, 58, 237, 0.1);
  border-radius: var(--radius-md);
  font-size: 1.25rem;
  flex-shrink: 0;
}

.paper__content {
  flex: 1;
}

.paper__title {
  font-size: 1.1rem;
  margin-bottom: var(--spacing-xs);
}

.paper__title a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-base), text-decoration-color var(--transition-base);
  text-underline-offset: 4px;
}

.paper__title a:hover {
  color: var(--accent-primary);
  text-decoration: underline;
  text-decoration-color: var(--accent-primary);
}

.paper__meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* ============================================
   Specification Table
   ============================================ */
.spec-table {
  background: var(--gradient-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.spec-table__header {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-subtle);
}

.spec-table__icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 255, 157, 0.1);
  border-radius: var(--radius-md);
}

.spec-table__title {
  font-size: 1.25rem;
}

.spec-table__rows {
  padding: var(--spacing-md);
}

.spec-row {
  display: flex;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-sm);
}

.spec-row:hover {
  background: rgba(255, 255, 255, 0.02);
}

.spec-row__label {
  width: 140px;
  flex-shrink: 0;
  font-weight: 500;
  color: var(--text-muted);
}

.spec-row__value {
  flex: 1;
  color: var(--text-primary);
}

.spec-row__value a {
  color: var(--accent-primary);
}

/* ============================================
   Community Section
   ============================================ */
.community-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.community-card {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: var(--gradient-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

.community-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-2px);
  text-decoration: none;
}

.community-card__icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  font-size: 1.5rem;
  flex-shrink: 0;
}

.community-card__icon--discord {
  background: rgba(88, 101, 242, 0.2);
  color: #5865F2;
}

.community-card__icon--github {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
}

.community-card__icon--mail {
  background: rgba(0, 255, 157, 0.1);
  color: var(--accent-primary);
}

.community-card__title {
  font-size: 1.1rem;
  color: var(--text-primary);
}

.community-card__desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

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

.footer__grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer__brand {
  max-width: 300px;
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.footer__desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: var(--spacing-md);
}

.footer__social {
  display: flex;
  gap: var(--spacing-sm);
}

.footer__social-link {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.footer__social-link:hover {
  background: var(--accent-primary);
  color: var(--bg-primary);
}

.footer__col-title {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.footer__links {
  list-style: none;
}

.footer__link {
  display: block;
  padding: var(--spacing-xs) 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--accent-primary);
}

.footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border-subtle);
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* ============================================
   Page Headers
   ============================================ */
.page-header {
  padding: 140px 0 var(--spacing-2xl);
  text-align: center;
  background: 
    radial-gradient(ellipse at 50% 0%, rgba(124, 58, 237, 0.15) 0%, transparent 50%),
    var(--bg-primary);
}

.page-header__label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--accent-primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--spacing-sm);
}

.page-header__title {
  margin-bottom: var(--spacing-md);
}

.page-header__desc {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 700px;
  margin: 0 auto;
}

/* ============================================
   Content Sections
   ============================================ */
.content-section {
  padding: var(--spacing-xl) 0;
}

.content-section + .content-section {
  border-top: 1px solid var(--border-subtle);
}

.content-section__title {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.content-section__title::before {
  content: '';
  width: 4px;
  height: 24px;
  background: var(--gradient-accent);
  border-radius: 2px;
}

/* ============================================
   CTA Section
   ============================================ */
.cta-section {
  text-align: center;
  padding: var(--spacing-2xl);
  background: var(--gradient-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  margin: var(--spacing-2xl) 0;
}

.cta-section__title {
  margin-bottom: var(--spacing-sm);
}

.cta-section__desc {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.cta-section__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 1024px) {
  .footer__grid {
    grid-template-columns: 1fr 1fr;
  }
  
  .footer__brand {
    grid-column: span 2;
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  :root {
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
  }
  
  .nav__menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-subtle);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
  }
  
  .nav__menu--open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav__toggle {
    display: flex;
  }
  
  .nav__cta {
    display: none;
  }
  
  .hero__stats {
    gap: var(--spacing-lg);
  }
  
  .hero__stat-value {
    font-size: 1.5rem;
  }
  
  .footer__grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .footer__brand {
    max-width: 100%;
  }
  
  .footer__social {
    justify-content: center;
  }
  
  .footer__bottom {
    flex-direction: column;
    gap: var(--spacing-sm);
    text-align: center;
  }
  
  .paper {
    flex-direction: column;
  }
  
  .spec-row {
    flex-direction: column;
    gap: var(--spacing-xs);
  }
  
  .spec-row__label {
    width: 100%;
  }
}

@media (max-width: 480px) {
  .hero__actions {
    flex-direction: column;
    width: 100%;
  }
  
  .hero__actions .btn {
    width: 100%;
  }
}

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

.text-center { text-align: center; }
.text-left { text-align: left; }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }

.grid { display: grid; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

@media (max-width: 768px) {
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }
}