/* ============================================
   MICRO:BIT EDUCATIONAL WEBSITE - GLOBAL STYLES
   Domain: microbit.io.vn
   Theme: Kid-friendly Pro-Max UX/UI
   ============================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@400;600;700;800;900&family=Fredoka:wght@400;500;600;700&display=swap');

/* ---------- CSS Custom Properties (Design Tokens) ---------- */
:root {
  /* Primary Palette - MakeCode Inspired */
  --clr-primary: #7B2FF7;
  --clr-primary-light: #A855F7;
  --clr-primary-dark: #5B1FBF;
  --clr-secondary: #00C2FF;
  --clr-secondary-light: #38D9FF;
  --clr-accent-yellow: #FFD43B;
  --clr-accent-green: #00E676;
  --clr-accent-pink: #FF6B9D;
  --clr-accent-orange: #FF9F43;
  --clr-accent-red: #FF5252;

  /* Backgrounds */
  --clr-bg-dark: #0D1117;
  --clr-bg-card: #161B22;
  --clr-bg-card-hover: #1C2333;
  --clr-bg-surface: #21262D;
  --clr-bg-light: #F0F6FC;
  --clr-bg-white: #FFFFFF;

  /* Text */
  --clr-text-primary: #F0F6FC;
  --clr-text-secondary: #8B949E;
  --clr-text-muted: #6E7681;
  --clr-text-dark: #1A1A2E;
  --clr-text-on-primary: #FFFFFF;

  /* Gradients */
  --grad-hero: linear-gradient(135deg, #7B2FF7 0%, #00C2FF 50%, #00E676 100%);
  --grad-primary: linear-gradient(135deg, #7B2FF7 0%, #A855F7 100%);
  --grad-secondary: linear-gradient(135deg, #00C2FF 0%, #00E676 100%);
  --grad-warm: linear-gradient(135deg, #FF6B9D 0%, #FFD43B 100%);
  --grad-cool: linear-gradient(135deg, #00C2FF 0%, #7B2FF7 100%);
  --grad-card: linear-gradient(145deg, rgba(123, 47, 247, 0.1) 0%, rgba(0, 194, 255, 0.05) 100%);
  --grad-glass: linear-gradient(135deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0.02) 100%);

  /* Borders */
  --border-subtle: 1px solid rgba(255, 255, 255, 0.08);
  --border-glow: 1px solid rgba(123, 47, 247, 0.3);
  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 16px;
  --border-radius-xl: 24px;
  --border-radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.4);
  --shadow-glow-purple: 0 0 30px rgba(123, 47, 247, 0.3);
  --shadow-glow-blue: 0 0 30px rgba(0, 194, 255, 0.3);
  --shadow-glow-green: 0 0 30px rgba(0, 230, 118, 0.3);

  /* Typography */
  --font-heading: 'Fredoka', 'Nunito', sans-serif;
  --font-body: 'Nunito', 'Segoe UI', sans-serif;
  --fs-hero: clamp(2.5rem, 6vw, 4.5rem);
  --fs-h1: clamp(2rem, 4vw, 3rem);
  --fs-h2: clamp(1.5rem, 3vw, 2.25rem);
  --fs-h3: clamp(1.25rem, 2.5vw, 1.75rem);
  --fs-h4: clamp(1.1rem, 2vw, 1.35rem);
  --fs-body: clamp(0.95rem, 1.5vw, 1.1rem);
  --fs-small: clamp(0.8rem, 1.2vw, 0.95rem);
  --fs-xs: 0.8rem;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Layout */
  --max-width: 1200px;
  --nav-height: 70px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
  --transition-fast: 0.2s var(--ease-out);
  --transition-normal: 0.35s var(--ease-out);
  --transition-slow: 0.5s var(--ease-out);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

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

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

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

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

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  line-height: 1.25;
  font-weight: 700;
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }
h4 { font-size: var(--fs-h4); }

/* ---------- Utility Classes ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

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

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

.section-header h2 {
  margin-bottom: var(--space-md);
  position: relative;
  display: inline-block;
}

.section-header h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--grad-hero);
  border-radius: var(--border-radius-full);
  margin: var(--space-sm) auto 0;
}

.section-header p {
  color: var(--clr-text-secondary);
  max-width: 600px;
  margin: 0 auto;
  font-size: var(--fs-body);
}

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

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

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 14px 32px;
  font-family: var(--font-heading);
  font-size: var(--fs-body);
  font-weight: 700;
  border: none;
  border-radius: var(--border-radius-full);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0.15);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.btn:hover::before {
  opacity: 1;
}

.btn-primary {
  background: var(--grad-primary);
  color: var(--clr-text-on-primary);
  box-shadow: var(--shadow-glow-purple);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 0 40px rgba(123, 47, 247, 0.5);
  color: #fff;
}

.btn-secondary {
  background: var(--grad-secondary);
  color: var(--clr-text-dark);
  box-shadow: var(--shadow-glow-blue);
}

.btn-secondary:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 0 40px rgba(0, 194, 255, 0.5);
  color: var(--clr-text-dark);
}

.btn-outline {
  background: transparent;
  color: var(--clr-text-primary);
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.btn-outline:hover {
  border-color: var(--clr-primary);
  color: var(--clr-primary-light);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 10px 22px;
  font-size: var(--fs-small);
}

.btn-lg {
  padding: 18px 42px;
  font-size: var(--fs-h4);
}

/* ---------- Cards ---------- */
.card {
  background: var(--clr-bg-card);
  border: var(--border-subtle);
  border-radius: var(--border-radius-lg);
  padding: var(--space-xl);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--grad-glass);
  opacity: 0;
  transition: opacity var(--transition-normal);
  pointer-events: none;
}

.card:hover {
  transform: translateY(-6px);
  border-color: rgba(123, 47, 247, 0.3);
  box-shadow: var(--shadow-lg), var(--shadow-glow-purple);
}

.card:hover::before {
  opacity: 1;
}

.card-icon {
  width: 64px;
  height: 64px;
  border-radius: var(--border-radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  margin-bottom: var(--space-lg);
  position: relative;
}

.card-icon.purple { background: rgba(123, 47, 247, 0.15); color: var(--clr-primary-light); }
.card-icon.blue { background: rgba(0, 194, 255, 0.15); color: var(--clr-secondary); }
.card-icon.green { background: rgba(0, 230, 118, 0.15); color: var(--clr-accent-green); }
.card-icon.yellow { background: rgba(255, 212, 59, 0.15); color: var(--clr-accent-yellow); }
.card-icon.pink { background: rgba(255, 107, 157, 0.15); color: var(--clr-accent-pink); }
.card-icon.orange { background: rgba(255, 159, 67, 0.15); color: var(--clr-accent-orange); }
.card-icon.red { background: rgba(255, 82, 82, 0.15); color: var(--clr-accent-red); }

.card h3 {
  margin-bottom: var(--space-sm);
}

.card p {
  color: var(--clr-text-secondary);
  font-size: var(--fs-small);
}

/* ---------- Tags / Badges ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 14px;
  font-size: var(--fs-xs);
  font-weight: 700;
  border-radius: var(--border-radius-full);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-purple { background: rgba(123, 47, 247, 0.2); color: var(--clr-primary-light); }
.badge-blue { background: rgba(0, 194, 255, 0.2); color: var(--clr-secondary); }
.badge-green { background: rgba(0, 230, 118, 0.2); color: var(--clr-accent-green); }
.badge-yellow { background: rgba(255, 212, 59, 0.2); color: var(--clr-accent-yellow); }
.badge-pink { background: rgba(255, 107, 157, 0.2); color: var(--clr-accent-pink); }
.badge-orange { background: rgba(255, 159, 67, 0.2); color: var(--clr-accent-orange); }

/* ---------- Navigation ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: var(--border-subtle);
  transition: all var(--transition-normal);
}

.navbar.scrolled {
  background: rgba(13, 17, 23, 0.95);
  box-shadow: var(--shadow-md);
}

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--clr-text-primary);
  text-decoration: none;
}

.nav-logo:hover { color: var(--clr-text-primary); }

.nav-logo .logo-icon {
  width: 40px;
  height: 40px;
  background: var(--grad-hero);
  border-radius: var(--border-radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  animation: pulse-glow 3s ease-in-out infinite;
}

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

.nav-links a {
  padding: 8px 16px;
  font-weight: 600;
  font-size: var(--fs-small);
  color: var(--clr-text-secondary);
  border-radius: var(--border-radius-md);
  transition: all var(--transition-fast);
  position: relative;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--clr-text-primary);
  background: rgba(123, 47, 247, 0.1);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 3px;
  background: var(--grad-primary);
  border-radius: var(--border-radius-full);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  z-index: 1001;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2.5px;
  background: var(--clr-text-primary);
  border-radius: var(--border-radius-full);
  transition: all var(--transition-fast);
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}
.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

/* ---------- Hero Section ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--nav-height);
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg .blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
  animation: float 8s ease-in-out infinite;
}

.hero-bg .blob-1 {
  width: 500px;
  height: 500px;
  background: var(--clr-primary);
  top: -10%;
  right: -5%;
  animation-delay: 0s;
}

.hero-bg .blob-2 {
  width: 400px;
  height: 400px;
  background: var(--clr-secondary);
  bottom: -10%;
  left: -5%;
  animation-delay: -3s;
}

.hero-bg .blob-3 {
  width: 300px;
  height: 300px;
  background: var(--clr-accent-green);
  top: 40%;
  left: 40%;
  animation-delay: -5s;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(123, 47, 247, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(123, 47, 247, 0.05) 1px, transparent 1px);
  background-size: 60px 60px;
  z-index: 1;
}

.hero .container {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}

.hero-content h1 {
  font-size: var(--fs-hero);
  font-weight: 900;
  margin-bottom: var(--space-lg);
  line-height: 1.1;
}

.hero-content .hero-subtitle {
  font-size: var(--fs-h4);
  color: var(--clr-text-secondary);
  margin-bottom: var(--space-2xl);
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-microbit {
  position: relative;
  width: 340px;
  height: 340px;
}

.microbit-board {
  width: 100%;
  height: 100%;
  background: var(--clr-bg-card);
  border: 2px solid rgba(123, 47, 247, 0.3);
  border-radius: var(--border-radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  box-shadow: var(--shadow-lg), var(--shadow-glow-purple);
  animation: board-float 6s ease-in-out infinite;
}

.led-matrix {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  padding: 20px;
}

.led {
  width: 28px;
  height: 28px;
  background: rgba(255, 82, 82, 0.15);
  border-radius: 50%;
  transition: all 0.3s ease;
}

.led.on {
  background: var(--clr-accent-red);
  box-shadow: 0 0 12px rgba(255, 82, 82, 0.6);
  animation: led-pulse 2s ease-in-out infinite;
}

.microbit-label {
  position: absolute;
  bottom: -16px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--grad-primary);
  color: white;
  padding: 6px 20px;
  border-radius: var(--border-radius-full);
  font-size: var(--fs-xs);
  font-weight: 700;
  font-family: var(--font-heading);
  white-space: nowrap;
}

/* Floating particles around the board */
.particle {
  position: absolute;
  border-radius: 50%;
  animation: orbit 6s linear infinite;
}

.particle-1 {
  width: 12px; height: 12px;
  background: var(--clr-accent-yellow);
  top: -20px; left: 30%;
  animation-duration: 4s;
}

.particle-2 {
  width: 8px; height: 8px;
  background: var(--clr-accent-green);
  bottom: 10%; right: -20px;
  animation-duration: 5s;
  animation-delay: -2s;
}

.particle-3 {
  width: 10px; height: 10px;
  background: var(--clr-secondary);
  top: 40%; left: -20px;
  animation-duration: 6s;
  animation-delay: -4s;
}

/* ---------- Feature Grid ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
}

.feature-grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

/* ---------- Split Layout ---------- */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}

.split.reverse {
  direction: rtl;
}

.split.reverse > * {
  direction: ltr;
}

/* ---------- Project Cards ---------- */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-xl);
}

.project-card {
  background: var(--clr-bg-card);
  border: var(--border-subtle);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.project-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg), var(--shadow-glow-purple);
  border-color: rgba(123, 47, 247, 0.3);
}

.project-card-thumb {
  height: 200px;
  position: relative;
  overflow: hidden;
}

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

.project-card:hover .project-card-thumb img {
  transform: scale(1.08);
}

.project-card-thumb .difficulty {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
}

.project-card-body {
  padding: var(--space-lg);
}

.project-card-body h3 {
  margin-bottom: var(--space-xs);
  font-size: var(--fs-h4);
}

.project-card-body p {
  color: var(--clr-text-secondary);
  font-size: var(--fs-small);
  margin-bottom: var(--space-md);
}

.project-card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  font-size: var(--fs-xs);
  color: var(--clr-text-muted);
}

.project-card-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ---------- IPO Model Infographic ---------- */
.ipo-flow {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: var(--space-lg);
  align-items: center;
}

.ipo-box {
  background: var(--clr-bg-card);
  border: var(--border-subtle);
  border-radius: var(--border-radius-lg);
  padding: var(--space-xl);
  text-align: center;
  transition: all var(--transition-normal);
}

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

.ipo-box .ipo-icon {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin: 0 auto var(--space-md);
}

.ipo-arrow {
  font-size: 2rem;
  color: var(--clr-primary-light);
  animation: arrow-bounce 1.5s ease-in-out infinite;
}

/* ---------- Comparison Table ---------- */
.comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
}

.comparison-card {
  background: var(--clr-bg-card);
  border: var(--border-subtle);
  border-radius: var(--border-radius-lg);
  padding: var(--space-2xl);
  text-align: center;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.comparison-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
}

.comparison-card.makecode::after {
  background: var(--grad-primary);
}

.comparison-card.python::after {
  background: var(--grad-secondary);
}

.comparison-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.comparison-card .tool-logo {
  width: 80px;
  height: 80px;
  border-radius: var(--border-radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  margin: 0 auto var(--space-lg);
}

.comparison-card h3 {
  margin-bottom: var(--space-sm);
}

.comparison-card p {
  color: var(--clr-text-secondary);
  margin-bottom: var(--space-lg);
}

.comparison-card ul {
  text-align: left;
}

.comparison-card ul li {
  padding: var(--space-xs) 0;
  color: var(--clr-text-secondary);
  font-size: var(--fs-small);
  display: flex;
  align-items: flex-start;
  gap: var(--space-xs);
}

.comparison-card ul li::before {
  content: '✓';
  color: var(--clr-accent-green);
  font-weight: 700;
  flex-shrink: 0;
}

/* ---------- Stats Bar ---------- */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-lg);
  padding: var(--space-2xl) 0;
}

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

.stat-item .stat-number {
  font-family: var(--font-heading);
  font-size: var(--fs-h1);
  font-weight: 900;
  background: var(--grad-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-item .stat-label {
  color: var(--clr-text-secondary);
  font-size: var(--fs-small);
  margin-top: var(--space-xs);
}

/* ---------- Footer ---------- */
.footer {
  background: var(--clr-bg-card);
  border-top: var(--border-subtle);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-2xl);
  margin-bottom: var(--space-2xl);
}

.footer-brand .footer-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-heading);
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--clr-text-primary);
  margin-bottom: var(--space-md);
}

.footer-brand .footer-logo .logo-icon {
  width: 36px;
  height: 36px;
  background: var(--grad-hero);
  border-radius: var(--border-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.footer-brand p {
  color: var(--clr-text-secondary);
  font-size: var(--fs-small);
  margin-bottom: var(--space-lg);
  max-width: 300px;
}

.footer-col h4 {
  font-size: var(--fs-body);
  margin-bottom: var(--space-md);
  color: var(--clr-text-primary);
}

.footer-col a {
  display: block;
  color: var(--clr-text-secondary);
  font-size: var(--fs-small);
  padding: 4px 0;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  border-top: var(--border-subtle);
  padding-top: var(--space-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-bottom p {
  color: var(--clr-text-muted);
  font-size: var(--fs-xs);
}

.footer-social {
  display: flex;
  gap: var(--space-sm);
}

.footer-social a {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--clr-bg-surface);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: all var(--transition-fast);
}

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

/* ---------- Page Header (Sub-pages) ---------- */
.page-header {
  padding: calc(var(--nav-height) + var(--space-3xl)) 0 var(--space-3xl);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center top, rgba(123, 47, 247, 0.15) 0%, transparent 60%);
  pointer-events: none;
}

.page-header h1 {
  font-size: var(--fs-h1);
  font-weight: 900;
  margin-bottom: var(--space-md);
  position: relative;
}

.page-header p {
  color: var(--clr-text-secondary);
  max-width: 600px;
  margin: 0 auto;
  position: relative;
}

/* ---------- Infographic Steps / Tips ---------- */
.tip-card {
  background: var(--clr-bg-card);
  border: var(--border-subtle);
  border-radius: var(--border-radius-lg);
  padding: var(--space-xl);
  display: flex;
  gap: var(--space-lg);
  align-items: flex-start;
  transition: all var(--transition-normal);
}

.tip-card:hover {
  border-color: rgba(123, 47, 247, 0.3);
  transform: translateX(6px);
}

.tip-card .tip-num {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--grad-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.tip-card h4 {
  margin-bottom: var(--space-xs);
}

.tip-card p {
  color: var(--clr-text-secondary);
  font-size: var(--fs-small);
}

/* ---------- Connector Pins Visual ---------- */
.pin-visual {
  display: flex;
  gap: var(--space-sm);
  justify-content: center;
  padding: var(--space-lg);
}

.pin {
  width: 40px;
  height: 60px;
  background: var(--clr-accent-yellow);
  border-radius: 0 0 var(--border-radius-md) var(--border-radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: var(--fs-xs);
  color: var(--clr-text-dark);
  transition: all var(--transition-fast);
}

.pin:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 12px rgba(255, 212, 59, 0.3);
}

/* ---------- Animations ---------- */
@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  25% { transform: translate(10px, -20px); }
  50% { transform: translate(-10px, 10px); }
  75% { transform: translate(15px, 15px); }
}

@keyframes board-float {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-15px) rotate(2deg); }
}

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

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 8px rgba(123, 47, 247, 0.4); }
  50% { box-shadow: 0 0 20px rgba(123, 47, 247, 0.7); }
}

@keyframes orbit {
  0% { transform: translateY(0) scale(1); }
  25% { transform: translateY(-10px) scale(1.2); }
  50% { transform: translateY(0) scale(1); }
  75% { transform: translateY(10px) scale(0.8); }
  100% { transform: translateY(0) scale(1); }
}

@keyframes arrow-bounce {
  0%, 100% { transform: translateX(0); }
  50% { transform: translateX(8px); }
}

@keyframes fade-in-up {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fade-in-left {
  from { opacity: 0; transform: translateX(-30px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes fade-in-right {
  from { opacity: 0; transform: translateX(30px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes scale-in {
  from { opacity: 0; transform: scale(0.9); }
  to { opacity: 1; transform: scale(1); }
}

.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.7s var(--ease-out);
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

.animate-delay-1 { transition-delay: 0.1s; }
.animate-delay-2 { transition-delay: 0.2s; }
.animate-delay-3 { transition-delay: 0.3s; }
.animate-delay-4 { transition-delay: 0.4s; }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-cta { justify-content: center; }

  .hero-visual { order: -1; }

  .hero-microbit { width: 280px; height: 280px; }

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

  .split.reverse {
    direction: ltr;
  }

  .ipo-flow {
    grid-template-columns: 1fr;
  }

  .ipo-arrow {
    transform: rotate(90deg);
    justify-self: center;
  }

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

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

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 320px;
    height: 100vh;
    background: var(--clr-bg-card);
    flex-direction: column;
    align-items: flex-start;
    padding: calc(var(--nav-height) + var(--space-xl)) var(--space-xl);
    gap: var(--space-xs);
    transition: right var(--transition-normal);
    border-left: var(--border-subtle);
    box-shadow: var(--shadow-lg);
  }

  .nav-links.open {
    right: 0;
  }

  .nav-links a {
    width: 100%;
    padding: var(--space-md) var(--space-lg);
    font-size: var(--fs-body);
  }

  .mobile-menu-btn { display: flex; }

  .hero-microbit { width: 240px; height: 240px; }

  .led { width: 20px; height: 20px; }

  .led-matrix { gap: 5px; padding: 14px; }

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

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

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

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

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

  .btn-lg { padding: 14px 32px; font-size: var(--fs-body); }
}

@media (max-width: 480px) {
  .hero-microbit { width: 200px; height: 200px; }

  .led { width: 16px; height: 16px; }

  .led-matrix { gap: 4px; padding: 10px; }

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

  .page-header { padding: calc(var(--nav-height) + var(--space-2xl)) 0 var(--space-2xl); }
}

/* Mobile overlay */
.nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.nav-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

/* ---------- Scroll to Top ---------- */
.scroll-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  background: var(--grad-primary);
  border: none;
  border-radius: 50%;
  color: white;
  font-size: 1.3rem;
  cursor: pointer;
  z-index: 900;
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-glow-purple);
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.scroll-top:hover {
  transform: translateY(-4px);
}