/* ============================================
   STARBIT UI Design System
   Based on: STARBIT UI 设计规范.md
   ============================================ */

/* ===========================================
   1. CSS Variables (Design Tokens)
   =========================================== */
:root {
  /* Colors - Primary */
  --color-primary: #2196F3;
  --color-primary-dark: #1565C0;
  --color-primary-light: #64B5F6;
  --color-primary-bg: #E3F2FD;

  /* Colors - Accent */
  --color-accent-orange: #FF9800;
  --color-accent-gold: #FFD54F;
  --color-navy: #0D2137;

  /* Colors - Text */
  --color-text-primary: #1A237E;
  --color-text-secondary: #37474F;
  --color-text-tertiary: #78909C;
  --color-text-inverse: #FFFFFF;

  /* Colors - Background (Optimized) */
  --color-bg-white: #FFFFFF;
  --color-bg-light: #F8FAFC;
  --color-bg-subtle: #F1F5F9;
  --color-bg-muted: #EEF4FB;
  --color-border: #E2E8F0;

  /* Colors - Status */
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;
  --color-info: #3B82F6;

  /* Gradients (Enhanced) */
  --gradient-hero: linear-gradient(135deg, #1565C0 0%, #1E88E5 50%, #42A5F5 100%);
  --gradient-button: linear-gradient(135deg, #1E88E5 0%, #42A5F5 100%);
  --gradient-dark: linear-gradient(135deg, #0D47A1 0%, #1565C0 50%, #1976D2 100%);
  --gradient-light: linear-gradient(180deg, #F8FAFC 0%, #EEF4FB 100%);
  --gradient-radial: radial-gradient(ellipse at 50% 0%, rgba(33, 150, 243, 0.08) 0%, transparent 70%);
  --gradient-mesh: radial-gradient(at 40% 20%, rgba(33, 150, 243, 0.05) 0%, transparent 50%),
                   radial-gradient(at 80% 80%, rgba(100, 181, 246, 0.05) 0%, transparent 50%);

  /* Typography */
  --font-family: 'Noto Sans TC', 'Noto Sans JP', 'Inter', 'PingFang TC', 'Microsoft JhengHei', sans-serif;
  --font-display: 48px;
  --font-h1: 36px;
  --font-h2: 28px;
  --font-h3: 20px;
  --font-body: 16px;
  --font-caption: 13px;
  --font-data: 36px;

  /* Spacing (8px base) */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 40px;
  --space-2xl: 64px;
  --space-3xl: 100px;

  /* Container */
  --container-max-width: 1280px;
  --container-padding: 24px;
  --container-padding-desktop: 64px;

  /* Border Radius */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);

  /* Transitions */
  --transition-fast: 150ms ease-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 400ms ease-out;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-body);
  line-height: 1.6;
  color: var(--color-text-secondary);
  background-color: var(--color-bg-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Japanese language support */
html[lang="ja"] body {
  font-family: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', 'Meiryo', sans-serif;
}

/* English language support */
html[lang="en"] body {
  font-family: 'Inter', 'Roboto', sans-serif;
}

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

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

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

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--container-padding-desktop);
  }
}

/* ===========================================
   4. Typography
   =========================================== */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-text-primary);
  line-height: 1.2;
  font-weight: 700;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 2px;
  color: var(--color-primary);
  margin-bottom: var(--space-md);
  text-transform: uppercase;
}

.section-title {
  font-size: var(--font-h1);
  margin-bottom: var(--space-md);
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 80px;
  height: 4px;
  background: var(--color-primary);
  margin: var(--space-md) auto 0;
  border-radius: var(--radius-full);
}

.section-desc {
  font-size: 18px;
  color: var(--color-text-tertiary);
  max-width: 600px;
  margin: 0 auto;
}

/* Light header for dark sections */
.section-header-light .section-tag {
  color: var(--color-accent-gold);
}

.section-header-light .section-title {
  color: var(--color-text-inverse);
}

.section-header-light .section-title::after {
  background: var(--color-accent-gold);
}

.section-header-light .section-desc {
  color: rgba(255, 255, 255, 0.8);
}

/* ===========================================
   5. Navigation
   =========================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--space-md) 0;
  transition: background-color var(--transition-base), box-shadow var(--transition-base);
}

.navbar.scrolled {
  background-color: var(--color-bg-white);
  box-shadow: var(--shadow-sm);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text-inverse);
  transition: color var(--transition-fast);
}

.navbar.scrolled .logo {
  color: var(--color-text-primary);
}

.logo-icon {
  font-size: 28px;
}

.nav-menu {
  display: none;
  align-items: center;
  gap: var(--space-xl);
}

@media (min-width: 1024px) {
  .nav-menu {
    display: flex;
  }
}

.nav-link {
  font-size: var(--font-body);
  font-weight: 500;
  color: rgba(255, 255, 255, 0.9);
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent-gold);
  transition: width var(--transition-fast);
}

.nav-link:hover::after {
  width: 100%;
}

.navbar.scrolled .nav-link {
  color: var(--color-text-secondary);
}

.navbar.scrolled .nav-link:hover {
  color: var(--color-primary);
}

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

/* Language Switcher */
.language-switcher {
  display: flex;
  background: rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-full);
  padding: 4px;
  backdrop-filter: blur(8px);
}

.navbar.scrolled .language-switcher {
  background: var(--color-bg-light);
}

.lang-btn {
  padding: 6px 12px;
  border: none;
  background: transparent;
  font-size: 13px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.8);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.navbar.scrolled .lang-btn {
  color: var(--color-text-tertiary);
}

.lang-btn.active {
  background: var(--color-bg-white);
  color: var(--color-primary);
}

.lang-btn:hover:not(.active) {
  background: rgba(255, 255, 255, 0.1);
}

.navbar.scrolled .lang-btn:hover:not(.active) {
  background: rgba(33, 150, 243, 0.1);
}

/* Hamburger Menu */
.hamburger {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  background: none;
  border: none;
  cursor: pointer;
}

@media (min-width: 1024px) {
  .hamburger {
    display: none;
  }
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-inverse);
  transition: all var(--transition-fast);
}

.navbar.scrolled .hamburger span {
  background: var(--color-text-primary);
}

/* ===========================================
   6. Buttons
   =========================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  font-family: inherit;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn:active {
  transform: scale(0.98);
}

/* Button Sizes */
.btn-sm {
  height: 32px;
  padding: 0 var(--space-md);
  font-size: 14px;
  border-radius: var(--radius-sm);
}

.btn-md {
  height: 40px;
  padding: 0 var(--space-lg);
  font-size: 15px;
}

.btn-lg {
  height: 48px;
  padding: 0 32px;
  font-size: 16px;
}

/* Button Variants */
.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

.btn-primary:hover {
  background: var(--gradient-button);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: transparent;
  color: var(--color-text-inverse);
  border: 2px solid rgba(255, 255, 255, 0.5);
}

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

.navbar.scrolled .btn-secondary {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.navbar.scrolled .btn-secondary:hover {
  background: var(--color-primary-bg);
}

.btn-secondary-light {
  background: rgba(255, 255, 255, 0.15);
  color: var(--color-text-inverse);
  border: 2px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(8px);
}

.btn-secondary-light:hover {
  background: rgba(255, 255, 255, 0.25);
  border-color: rgba(255, 255, 255, 0.5);
}

.btn-white {
  background: var(--color-bg-white);
  color: var(--color-primary-dark);
}

.btn-white:hover {
  background: var(--color-primary-bg);
  box-shadow: var(--shadow-md);
}

.btn-outline-white {
  background: transparent;
  color: var(--color-text-inverse);
  border: 2px solid var(--color-text-inverse);
}

.btn-outline-white:hover {
  background: rgba(255, 255, 255, 0.1);
}

/* ===========================================
   7. Sections
   =========================================== */
.section {
  padding: var(--space-3xl) 0;
  position: relative;
}

.section-white {
  background: var(--color-bg-white);
  background-image: var(--gradient-mesh);
  position: relative;
}

.section-white::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 200px;
  background: var(--gradient-radial);
  pointer-events: none;
}

.section-light {
  background: var(--gradient-light);
  position: relative;
}

.section-light::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-mesh);
  pointer-events: none;
}

.section-dark {
  background: var(--gradient-dark);
  color: var(--color-text-inverse);
  position: relative;
  overflow: hidden;
}

.section-dark::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 80%;
  height: 150%;
  background: radial-gradient(ellipse, rgba(255, 255, 255, 0.05) 0%, transparent 70%);
  pointer-events: none;
}

.section-dark::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 60%;
  height: 100%;
  background: radial-gradient(ellipse, rgba(100, 181, 246, 0.1) 0%, transparent 60%);
  pointer-events: none;
}

.section-wave-top,
.section-wave-bottom {
  position: absolute;
  left: 0;
  right: 0;
  overflow: hidden;
  line-height: 0;
}

.section-wave-top {
  top: 0;
}

.section-wave-bottom {
  bottom: 0;
}

.section-wave-top svg,
.section-wave-bottom svg {
  width: 100%;
  height: 80px;
}

@media (min-width: 768px) {
  .section-wave-top svg,
  .section-wave-bottom svg {
    height: 120px;
  }
}

/* ===========================================
   8. Hero Section
   =========================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: var(--gradient-hero);
  z-index: -1;
}

.hero-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 70% 20%, rgba(255, 255, 255, 0.15) 0%, transparent 50%),
    radial-gradient(ellipse at 20% 80%, rgba(100, 181, 246, 0.2) 0%, transparent 40%),
    radial-gradient(ellipse at 90% 90%, rgba(13, 71, 161, 0.3) 0%, transparent 50%);
}

.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

.hero-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2xl);
  align-items: center;
}

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

.hero-content {
  text-align: center;
}

@media (min-width: 1024px) {
  .hero-content {
    text-align: left;
  }
}

.hero-title {
  font-size: clamp(32px, 5vw, var(--font-display));
  color: var(--color-text-inverse);
  margin-bottom: var(--space-lg);
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 18px;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: var(--space-xl);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

@media (min-width: 768px) {
  .hero-stats {
    grid-template-columns: repeat(4, 1fr);
  }
}

.stat-item {
  text-align: center;
}

@media (min-width: 1024px) {
  .stat-item {
    text-align: left;
  }
}

.stat-number {
  display: block;
  font-size: var(--font-data);
  font-weight: 700;
  color: var(--color-text-inverse);
  line-height: 1.1;
}

.stat-label {
  font-size: var(--font-caption);
  color: rgba(255, 255, 255, 0.7);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: center;
}

@media (min-width: 1024px) {
  .hero-actions {
    justify-content: flex-start;
  }
}

/* Hero Visual */
.hero-visual {
  display: none;
}

@media (min-width: 1024px) {
  .hero-visual {
    display: block;
  }
}

.hero-illustration {
  position: relative;
  width: 100%;
  height: 400px;
}

.floating-card {
  position: absolute;
  background: rgba(255, 255, 255, 0.95);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  animation: float 3s ease-in-out infinite;
}

.floating-card .card-icon {
  font-size: 24px;
}

.floating-card .card-text {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-primary);
}

.card-1 {
  top: 10%;
  left: 10%;
  animation-delay: 0s;
}

.card-2 {
  top: 40%;
  right: 5%;
  animation-delay: 1s;
}

.card-3 {
  bottom: 15%;
  left: 15%;
  animation-delay: 2s;
}

.center-orb {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 140px;
  height: 140px;
  background: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 60px rgba(33, 150, 243, 0.5);
  animation: pulse 2s ease-in-out infinite;
}

.orb-icon {
  font-size: 48px;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-15px);
  }
}

@keyframes pulse {
  0%, 100% {
    transform: translate(-50%, -50%) scale(1);
    box-shadow: 0 0 60px rgba(33, 150, 243, 0.5);
  }
  50% {
    transform: translate(-50%, -50%) scale(1.05);
    box-shadow: 0 0 80px rgba(33, 150, 243, 0.7);
  }
}

.hero-wave {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  line-height: 0;
}

.hero-wave svg {
  width: 100%;
  height: 80px;
}

@media (min-width: 768px) {
  .hero-wave svg {
    height: 120px;
  }
}

/* ===========================================
   9. Feature Cards
   =========================================== */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

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

.feature-card {
  background: linear-gradient(135deg, #FFFFFF 0%, #F8FAFC 100%);
  padding: var(--space-xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: all var(--transition-base);
  border: 1px solid rgba(226, 232, 240, 0.5);
  cursor: pointer;
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  margin-bottom: var(--space-lg);
}

.feature-title {
  font-size: var(--font-h3);
  margin-bottom: var(--space-md);
}

.feature-desc {
  color: var(--color-text-tertiary);
}

/* ===========================================
   10. Timeline / Learning Path
   =========================================== */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 16px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: rgba(255, 255, 255, 0.3);
}

.timeline-item {
  position: relative;
  padding-bottom: var(--space-xl);
  transition: all 0.3s ease;
  display: block;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

a.timeline-item {
  margin-bottom: 20px;
}

a.timeline-item:hover {
  transform: scale(1.02);
  transform-origin: left center;
}

a.timeline-item:hover .timeline-title {
  color: #2196F3;
}

.timeline-marker {
  position: absolute;
  left: -40px;
  width: 32px;
  height: 32px;
  background: var(--color-accent-gold);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
  color: var(--color-navy);
}

.timeline-content {
  background: rgba(255, 255, 255, 0.1);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  backdrop-filter: blur(8px);
}

.timeline-title {
  font-size: var(--font-h3);
  color: var(--color-text-inverse);
  margin-bottom: var(--space-sm);
}

.timeline-desc {
  color: rgba(255, 255, 255, 0.8);
}

/* ===========================================
   11. Skills Section
   =========================================== */
.skills-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
}

.tab-btn {
  padding: var(--space-sm) var(--space-lg);
  background: transparent;
  border: none;
  font-family: inherit;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-tertiary);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.tab-btn.active {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

@media (min-width: 768px) {
  .skills-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.skill-card {
  background: linear-gradient(145deg, #FFFFFF 0%, #F8FAFC 100%);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: all var(--transition-base);
  cursor: pointer;
  border: 1px solid rgba(226, 232, 240, 0.6);
}

.skill-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.skill-card[data-category]:not([data-category="productivity"]) {
  display: none;
}

.skill-icon {
  font-size: 32px;
  margin-bottom: var(--space-sm);
}

.skill-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.skill-desc {
  font-size: var(--font-caption);
  color: var(--color-text-tertiary);
}

/* ===========================================
   12. Resources Section
   =========================================== */
.resources-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

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

.resource-card {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  background: linear-gradient(135deg, #FFFFFF 0%, #FAFBFC 100%);
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
  border: 1px solid rgba(226, 232, 240, 0.5);
  cursor: pointer;
  position: relative;
}

.resource-lang-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: transparent;
  color: var(--color-primary);
  font-size: 11px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--color-primary);
}

.resource-lang-badge.resource-lang-zh {
  color: #10B981;
  border-color: #10B981;
}

.resource-card:hover {
  transform: translateX(8px);
  box-shadow: var(--shadow-md);
}

.resource-icon {
  font-size: 32px;
  flex-shrink: 0;
}

.resource-content {
  flex: 1;
}

.resource-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.resource-desc {
  font-size: var(--font-caption);
  color: var(--color-text-tertiary);
}

.resource-arrow {
  font-size: 20px;
  color: var(--color-primary);
  transition: transform var(--transition-fast);
}

.resource-card:hover .resource-arrow {
  transform: translateX(4px);
}

/* ===========================================
   13. Community Section
   =========================================== */
.community-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

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

.community-card {
  background: linear-gradient(145deg, #FFFFFF 0%, #F8FAFC 100%);
  padding: var(--space-xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: all var(--transition-base);
  border: 1px solid rgba(226, 232, 240, 0.5);
  cursor: pointer;
}

.community-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
}

.community-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto var(--space-lg);
  background: var(--color-primary-bg);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
}

.community-title {
  font-size: var(--font-h3);
  margin-bottom: var(--space-sm);
}

.community-desc {
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-lg);
}

/* ===========================================
   14. CTA Section
   =========================================== */
.section-cta {
  background: var(--gradient-dark);
  text-align: center;
  padding: var(--space-3xl) 0;
  position: relative;
  overflow: hidden;
}

.section-cta::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 120%;
  height: 100%;
  background: radial-gradient(ellipse at center top, rgba(255, 255, 255, 0.08) 0%, transparent 60%);
  pointer-events: none;
}

.cta-title {
  font-size: var(--font-h1);
  color: var(--color-text-inverse);
  margin-bottom: var(--space-md);
}

.cta-desc {
  font-size: 18px;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: var(--space-xl);
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
}

/* ===========================================
   15. Footer
   =========================================== */
.footer {
  background: linear-gradient(180deg, #F1F5F9 0%, #E2E8F0 100%);
  padding: var(--space-2xl) 0 var(--space-lg);
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-primary-light), transparent);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
}

.footer-brand .logo {
  color: var(--color-text-primary);
  margin-bottom: var(--space-md);
}

.footer-tagline {
  color: var(--color-text-tertiary);
}

.footer-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  letter-spacing: 1px;
}

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

.footer-links a {
  color: var(--color-text-tertiary);
  font-size: 14px;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  text-align: center;
}

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

.footer-credit,
.footer-copyright {
  font-size: var(--font-caption);
  color: var(--color-text-tertiary);
}

/* ===========================================
   16. Animations
   =========================================== */
@media (prefers-reduced-motion: no-preference) {
  .fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--transition-slow), transform var(--transition-slow);
  }

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

/* ===========================================
   17. Responsive Typography
   =========================================== */
@media (max-width: 768px) {
  :root {
    --font-display: 32px;
    --font-h1: 28px;
    --font-h2: 22px;
    --font-h3: 18px;
    --font-body: 15px;
    --font-data: 28px;
  }

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

/* ===========================================
   18. Mobile Menu
   =========================================== */
@media (max-width: 1023px) {
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 320px;
    height: 100vh;
    background: var(--color-bg-white);
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-3xl) var(--space-lg);
    gap: var(--space-lg);
    box-shadow: var(--shadow-lg);
    transition: right var(--transition-base);
  }

  .nav-menu.active {
    display: flex;
    right: 0;
  }

  .nav-menu .nav-link {
    color: var(--color-text-primary);
    font-size: 18px;
  }
}

/* Mobile menu overlay */
.menu-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: 999;
}

.menu-overlay.active {
  opacity: 1;
  visibility: visible;
}

/* QR Code Modal */
.qr-modal {
  display: none;
  position: fixed;
  z-index: 10000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.7);
  animation: fadeIn 0.3s ease;
}

.qr-modal-content {
  position: relative;
  background-color: #fff;
  margin: 10% auto;
  padding: 30px;
  border-radius: 12px;
  max-width: 400px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  animation: slideIn 0.3s ease;
}

.qr-modal-close {
  position: absolute;
  right: 15px;
  top: 10px;
  color: #aaa;
  font-size: 28px;
  font-weight: bold;
  cursor: pointer;
  transition: color 0.3s ease;
}

.qr-modal-close:hover,
.qr-modal-close:focus {
  color: #000;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideIn {
  from {
    transform: translateY(-50px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

/* Mobile responsive for modal */
@media (max-width: 768px) {
  .qr-modal-content {
    margin: 20% 20px;
    padding: 20px;
  }
}