/* ===== IndianElucidBiology - Custom Styles v2 ===== */
/* ===== Beautiful, animated, interactive ===== */

:root {
  --ieb-primary: #0d6efd;
  --ieb-secondary: #6f42c1;
  --ieb-accent: #20c997;
  --ieb-dark: #1a1a2e;
  --ieb-darker: #0f0f1e;
  --ieb-card-bg: #ffffff;
  --ieb-body-bg: #f8f9fa;
  --ieb-text: #212529;
  --ieb-text-muted: #6c757d;
  --ieb-code-bg: #1e1e2e;
  --ieb-code-text: #cdd6f4;
  --ieb-border: rgba(0,0,0,0.08);
  --ieb-gradient: linear-gradient(135deg, #0d6efd 0%, #6f42c1 50%, #20c997 100%);
  --ieb-hero-gradient: linear-gradient(135deg, #0f0c29 0%, #302b63 50%, #24243e 100%);
  --ieb-glow-primary: rgba(13,110,253,0.35);
  --ieb-glow-accent: rgba(32,201,151,0.3);
  --ieb-glass: rgba(255,255,255,0.7);
  --ieb-glass-border: rgba(255,255,255,0.25);
  --ieb-shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
  --ieb-shadow-md: 0 8px 30px rgba(0,0,0,0.08);
  --ieb-shadow-lg: 0 20px 60px rgba(0,0,0,0.12);
  --ieb-shadow-glow: 0 0 40px var(--ieb-glow-primary);
}

[data-bs-theme="dark"] {
  --ieb-card-bg: #1e1e2e;
  --ieb-body-bg: #11111b;
  --ieb-text: #cdd6f4;
  --ieb-text-muted: #a6adc8;
  --ieb-border: rgba(255,255,255,0.08);
  --ieb-code-bg: #0d0d17;
  --ieb-glass: rgba(30,30,46,0.8);
  --ieb-glass-border: rgba(255,255,255,0.06);
  --ieb-shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --ieb-shadow-md: 0 8px 30px rgba(0,0,0,0.4);
  --ieb-shadow-lg: 0 20px 60px rgba(0,0,0,0.5);
}

*, *::before, *::after { box-sizing: border-box; }

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--ieb-body-bg);
  color: var(--ieb-text);
  scroll-behavior: smooth;
  overflow-x: hidden;
}

/* ===== Selection Color ===== */
::selection { background: var(--ieb-primary); color: #fff; }
::-moz-selection { background: var(--ieb-primary); color: #fff; }

/* ===== Glassmorphism Navbar ===== */
.navbar-brand {
  font-weight: 800;
  font-size: 1.35rem;
  letter-spacing: -0.5px;
}
.navbar-brand .brand-indian { color: #ff9933; }
.navbar-brand .brand-elucid { color: var(--ieb-primary); }
.navbar-brand .brand-biology { color: var(--ieb-accent); }

.navbar {
  background: var(--ieb-glass) !important;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--ieb-glass-border);
  box-shadow: var(--ieb-shadow-sm);
  transition: all 0.4s ease;
}
.navbar.scrolled {
  box-shadow: var(--ieb-shadow-md);
}
.navbar .nav-link {
  position: relative;
  font-weight: 500;
  transition: color 0.3s;
}
.navbar .nav-link::after {
  content: '';
  position: absolute;
  bottom: 0; left: 50%; width: 0; height: 2px;
  background: var(--ieb-gradient);
  transition: all 0.3s ease;
  transform: translateX(-50%);
}
.navbar .nav-link:hover::after,
.navbar .nav-link.active::after {
  width: 70%;
}

/* ===== Hero Section — Animated Gradient + Particles ===== */
.hero-section {
  background: var(--ieb-hero-gradient);
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}
.hero-section::before {
  content: '';
  position: absolute;
  top: -50%; left: -50%; width: 200%; height: 200%;
  background: radial-gradient(circle at 20% 50%, rgba(13,110,253,0.15) 0%, transparent 50%),
              radial-gradient(circle at 80% 20%, rgba(111,66,193,0.12) 0%, transparent 50%),
              radial-gradient(circle at 50% 80%, rgba(32,201,151,0.10) 0%, transparent 50%);
  animation: heroOrbs 15s ease-in-out infinite;
  z-index: 0;
}
@keyframes heroOrbs {
  0%, 100% { transform: translate(0,0) rotate(0deg); }
  33% { transform: translate(30px, -20px) rotate(120deg); }
  66% { transform: translate(-20px, 15px) rotate(240deg); }
}
.hero-section::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 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='0.04'%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: 0.6;
  z-index: 0;
}
.hero-section .container { position: relative; z-index: 1; }
.hero-title {
  font-size: 3.8rem;
  font-weight: 900;
  line-height: 1.08;
  color: #fff;
  letter-spacing: -1px;
}
.hero-subtitle {
  font-size: 1.25rem;
  color: rgba(255,255,255,0.75);
  max-width: 600px;
  line-height: 1.7;
}
.hero-mascot {
  max-height: 420px;
  filter: drop-shadow(0 20px 50px rgba(0,0,0,0.5));
  animation: float 4s ease-in-out infinite;
}
@keyframes float {
  0%, 100% { transform: translateY(0px) rotate(0deg); }
  50% { transform: translateY(-18px) rotate(1deg); }
}

/* Animated gradient text */
.gradient-text {
  background: linear-gradient(270deg, #0d6efd, #6f42c1, #20c997, #0d6efd);
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 6s ease infinite;
}
@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* Hero CTA buttons */
.hero-section .btn-primary {
  background: var(--ieb-gradient);
  border: none;
  box-shadow: 0 4px 20px var(--ieb-glow-primary);
  transition: all 0.3s;
}
.hero-section .btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px var(--ieb-glow-primary);
}
.hero-section .btn-outline-light {
  border: 1px solid rgba(255,255,255,0.3);
  backdrop-filter: blur(10px);
  transition: all 0.3s;
}
.hero-section .btn-outline-light:hover {
  background: rgba(255,255,255,0.1);
  transform: translateY(-3px);
}

/* ===== Tutorial Cards — Glass + Glow ===== */
.tutorial-card {
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
  border-radius: 20px;
  overflow: hidden;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}
.tutorial-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; height: 3px;
  background: var(--ieb-gradient);
  opacity: 0;
  transition: opacity 0.4s;
}
.tutorial-card:hover::before { opacity: 1; }
.tutorial-card:hover {
  transform: translateY(-10px) scale(1.02);
  box-shadow: var(--ieb-shadow-lg), 0 0 40px rgba(13,110,253,0.08);
  border-color: var(--ieb-primary);
}
.tutorial-card .card-icon {
  width: 64px;
  height: 64px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  transition: transform 0.4s;
}
.tutorial-card:hover .card-icon { transform: scale(1.1) rotate(-5deg); }
.tutorial-card .difficulty-badge {
  font-size: 0.7rem;
  padding: 4px 10px;
  border-radius: 20px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.badge-beginner { background: #d1fae5; color: #065f46; }
.badge-intermediate { background: #fef3c7; color: #92400e; }
.badge-advanced { background: #fce7f3; color: #9d174d; }

[data-bs-theme="dark"] .badge-beginner { background: #064e3b; color: #6ee7b7; }
[data-bs-theme="dark"] .badge-intermediate { background: #78350f; color: #fcd34d; }
[data-bs-theme="dark"] .badge-advanced { background: #831843; color: #f9a8d4; }

/* Card stagger animation */
.tutorial-card-col:nth-child(1) .tutorial-card { transition-delay: 0s; }
.tutorial-card-col:nth-child(2) .tutorial-card { transition-delay: 0.05s; }
.tutorial-card-col:nth-child(3) .tutorial-card { transition-delay: 0.1s; }
.tutorial-card-col:nth-child(4) .tutorial-card { transition-delay: 0.15s; }
.tutorial-card-col:nth-child(5) .tutorial-card { transition-delay: 0.2s; }
.tutorial-card-col:nth-child(6) .tutorial-card { transition-delay: 0.25s; }
.tutorial-card-col:nth-child(7) .tutorial-card { transition-delay: 0.3s; }
.tutorial-card-col:nth-child(8) .tutorial-card { transition-delay: 0.35s; }
.tutorial-card-col:nth-child(9) .tutorial-card { transition-delay: 0.4s; }
.tutorial-card-col:nth-child(10) .tutorial-card { transition-delay: 0.45s; }
.tutorial-card-col:nth-child(11) .tutorial-card { transition-delay: 0.5s; }
.tutorial-card-col:nth-child(12) .tutorial-card { transition-delay: 0.55s; }

/* ===== Tutorial Page Layout ===== */
.tutorial-hero {
  padding: 110px 0 70px;
  background: var(--ieb-hero-gradient);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.tutorial-hero::before {
  content: '';
  position: absolute;
  top: -50%; left: -50%; width: 200%; height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(13,110,253,0.1) 0%, transparent 50%),
              radial-gradient(circle at 70% 30%, rgba(111,66,193,0.08) 0%, transparent 50%);
  animation: heroOrbs 20s ease-in-out infinite;
  z-index: 0;
}
.tutorial-hero .container { position: relative; z-index: 1; }
.tutorial-content {
  max-width: 900px;
  margin: 0 auto;
}

/* ===== Code Blocks — Sleek Terminal Look ===== */
.code-block-wrapper {
  position: relative;
  margin: 1.5rem 0;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.05);
  box-shadow: var(--ieb-shadow-md);
  transition: box-shadow 0.3s;
}
.code-block-wrapper:hover {
  box-shadow: var(--ieb-shadow-lg);
}
.code-block-header {
  background: #181825;
  color: #a6adc8;
  padding: 10px 16px;
  font-size: 0.8rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
}
.code-block-header::before {
  content: '';
  display: inline-flex;
  gap: 6px;
  margin-right: 10px;
  width: 12px; height: 12px;
  background: #ff5f57;
  border-radius: 50%;
  box-shadow: 18px 0 0 #febc2e, 36px 0 0 #28c840;
}
.code-block-wrapper pre {
  margin: 0;
  padding: 20px;
  background: var(--ieb-code-bg);
  color: var(--ieb-code-text);
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.85rem;
  line-height: 1.75;
  overflow-x: auto;
  tab-size: 4;
}
.btn-copy {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.15);
  color: #a6adc8;
  padding: 4px 14px;
  border-radius: 8px;
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.25s;
}
.btn-copy:hover {
  background: var(--ieb-primary);
  color: #fff;
  border-color: var(--ieb-primary);
  transform: scale(1.05);
}
.btn-copy.copied {
  background: var(--ieb-accent);
  color: #fff;
  border-color: var(--ieb-accent);
}

/* ===== Byte Callout Boxes — Animated ===== */
.byte-callout {
  border-radius: 18px;
  padding: 24px;
  margin: 2rem 0;
  display: flex;
  gap: 20px;
  align-items: flex-start;
  border: 1px solid var(--ieb-border);
  transition: transform 0.3s, box-shadow 0.3s;
}
.byte-callout:hover {
  transform: translateX(6px);
  box-shadow: var(--ieb-shadow-md);
}
.byte-callout img {
  width: 90px;
  flex-shrink: 0;
  transition: transform 0.4s;
}
.byte-callout:hover img {
  transform: scale(1.1) rotate(-5deg);
}
.byte-callout.byte-tip {
  background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
  border-color: #6ee7b7;
}
.byte-callout.byte-warn {
  background: linear-gradient(135deg, #fefce8 0%, #fef3c7 100%);
  border-color: #fcd34d;
}
.byte-callout.byte-info {
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
  border-color: #93c5fd;
}
.byte-callout.byte-key {
  background: linear-gradient(135deg, #fdf4ff 0%, #fae8ff 100%);
  border-color: #d8b4fe;
}
.byte-callout.byte-wait {
  background: linear-gradient(135deg, #fff7ed 0%, #fed7aa 100%);
  border-color: #fdba74;
}
[data-bs-theme="dark"] .byte-callout.byte-tip { background: linear-gradient(135deg, #022c22 0%, #064e3b 100%); border-color: #065f46; }
[data-bs-theme="dark"] .byte-callout.byte-warn { background: linear-gradient(135deg, #422006 0%, #78350f 100%); border-color: #92400e; }
[data-bs-theme="dark"] .byte-callout.byte-info { background: linear-gradient(135deg, #172554 0%, #1e3a5f 100%); border-color: #1e40af; }
[data-bs-theme="dark"] .byte-callout.byte-key { background: linear-gradient(135deg, #2e1065 0%, #3b0764 100%); border-color: #6b21a8; }
[data-bs-theme="dark"] .byte-callout.byte-wait { background: linear-gradient(135deg, #431407 0%, #7c2d12 100%); border-color: #c2410c; }
[data-bs-theme="dark"] .byte-callout { color: #cdd6f4; }

/* ===== Progress Tracker ===== */
.progress-tracker {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 4px;
  background: var(--ieb-gradient);
  z-index: 9999;
  transition: width 0.1s;
}

/* ===== Sidebar TOC ===== */
.toc-sidebar {
  position: sticky;
  top: 80px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
}
.toc-sidebar .nav-link {
  color: var(--ieb-text-muted);
  font-size: 0.85rem;
  padding: 6px 16px;
  border-left: 2px solid transparent;
  transition: all 0.2s;
}
.toc-sidebar .nav-link:hover,
.toc-sidebar .nav-link.active {
  color: var(--ieb-primary);
  border-left-color: var(--ieb-primary);
  background: rgba(13,110,253,0.05);
}

/* ===== Parameter Table ===== */
.param-table {
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--ieb-border);
  margin: 1.5rem 0;
}
.param-table table {
  margin: 0;
}
.param-table thead {
  background: var(--ieb-dark);
  color: #fff;
}
.param-table th, .param-table td {
  padding: 12px 16px;
  font-size: 0.9rem;
}
.param-table code {
  background: rgba(13,110,253,0.1);
  color: var(--ieb-primary);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85rem;
}

/* ===== Threshold Decision Box — Gradient Border ===== */
.decision-box {
  background: var(--ieb-card-bg);
  border: 2px solid transparent;
  border-radius: 18px;
  padding: 24px;
  margin: 2rem 0;
  background-clip: padding-box;
  position: relative;
}
.decision-box::before {
  content: '';
  position: absolute;
  inset: -2px;
  border-radius: 20px;
  background: var(--ieb-gradient);
  z-index: -1;
}
.decision-box h5 {
  color: var(--ieb-primary);
  font-weight: 700;
}

/* ===== Step Counter — Animated ===== */
.step-number {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--ieb-gradient);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1rem;
  flex-shrink: 0;
  box-shadow: 0 4px 15px var(--ieb-glow-primary);
  transition: transform 0.3s;
}
h2:hover .step-number { transform: scale(1.2) rotate(-10deg); }

/* ===== Footer — Gradient Top Line ===== */
.site-footer {
  background: var(--ieb-dark);
  color: rgba(255,255,255,0.7);
  padding: 60px 0 30px;
  position: relative;
}
.site-footer::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--ieb-gradient);
}
.site-footer a { color: var(--ieb-accent); text-decoration: none; transition: color 0.2s; }
.site-footer a:hover { color: #fff; }

/* ===== Dark Mode Toggle — Animated ===== */
.theme-toggle {
  background: transparent;
  border: 1px solid var(--ieb-border);
  color: var(--ieb-text);
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  font-size: 1.1rem;
}
.theme-toggle:hover {
  background: var(--ieb-gradient);
  color: #fff;
  border-color: transparent;
  transform: rotate(30deg) scale(1.1);
  box-shadow: 0 0 20px var(--ieb-glow-primary);
}

/* ===== Animations — Rich & Staggered ===== */
.fade-up {
  opacity: 0;
  transform: translateY(40px);
  transition: all 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}
.fade-left {
  opacity: 0;
  transform: translateX(-40px);
  transition: all 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
.fade-left.visible { opacity: 1; transform: translateX(0); }
.fade-right {
  opacity: 0;
  transform: translateX(40px);
  transition: all 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
.fade-right.visible { opacity: 1; transform: translateX(0); }
.scale-in {
  opacity: 0;
  transform: scale(0.9);
  transition: all 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}
.scale-in.visible { opacity: 1; transform: scale(1); }

/* Stagger children */
.stagger-children > *:nth-child(1) { transition-delay: 0.0s; }
.stagger-children > *:nth-child(2) { transition-delay: 0.08s; }
.stagger-children > *:nth-child(3) { transition-delay: 0.16s; }
.stagger-children > *:nth-child(4) { transition-delay: 0.24s; }
.stagger-children > *:nth-child(5) { transition-delay: 0.32s; }
.stagger-children > *:nth-child(6) { transition-delay: 0.40s; }

/* Pulse glow for important elements */
@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 5px var(--ieb-glow-primary); }
  50% { box-shadow: 0 0 25px var(--ieb-glow-primary); }
}
.pulse-glow { animation: pulseGlow 3s ease-in-out infinite; }

/* Typing cursor */
@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }
.typing-cursor::after {
  content: '|';
  animation: blink 1s step-end infinite;
  color: var(--ieb-accent);
  font-weight: 400;
}

/* Shimmer loading effect */
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
.shimmer {
  background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.1) 50%, transparent 100%);
  background-size: 200% 100%;
  animation: shimmer 2s linear infinite;
}

/* ===== Stats Counter ===== */
.stat-number {
  font-size: 2.8rem;
  font-weight: 900;
  background: var(--ieb-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== Mnemonic Box ===== */
.mnemonic-box {
  background: linear-gradient(135deg, #fefce8 0%, #fef9c3 100%);
  border: 2px dashed #eab308;
  border-radius: 16px;
  padding: 22px 24px;
  margin: 1.5rem 0;
  position: relative;
}
[data-bs-theme="dark"] .mnemonic-box {
  background: linear-gradient(135deg, #422006 0%, #713f12 100%);
  border-color: #ca8a04;
}
.mnemonic-box .mnemonic-label {
  position: absolute;
  top: -12px; left: 20px;
  background: #eab308;
  color: #422006;
  font-size: 0.7rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 2px 12px;
  border-radius: 8px;
}
.mnemonic-box .mnemonic-phrase {
  font-size: 1.3rem;
  font-weight: 800;
  color: #92400e;
  margin-bottom: 6px;
}
[data-bs-theme="dark"] .mnemonic-box .mnemonic-phrase { color: #fde68a; }
.mnemonic-box .mnemonic-detail { font-size: 0.88rem; margin: 0; }

/* ===== Thumb Rule Box ===== */
.thumb-rule {
  background: var(--ieb-card-bg);
  border-left: 4px solid var(--ieb-accent);
  border-radius: 0 12px 12px 0;
  padding: 16px 20px;
  margin: 1rem 0;
  box-shadow: var(--ieb-shadow-sm);
  transition: all 0.3s;
}
.thumb-rule:hover {
  transform: translateX(4px);
  box-shadow: var(--ieb-shadow-md);
}
.thumb-rule strong { color: var(--ieb-accent); }

/* ===== Section Divider ===== */
.section-divider {
  height: 3px;
  background: var(--ieb-gradient);
  border: none;
  border-radius: 3px;
  margin: 3rem 0;
  opacity: 0.3;
}

/* ===== Badge Pill Tags ===== */
.tag-pill {
  display: inline-block;
  padding: 3px 10px;
  font-size: 0.72rem;
  font-weight: 600;
  border-radius: 20px;
  background: rgba(13,110,253,0.1);
  color: var(--ieb-primary);
  margin: 2px;
  transition: all 0.2s;
}
.tag-pill:hover {
  background: var(--ieb-primary);
  color: #fff;
  transform: scale(1.05);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero-title { font-size: 2.4rem; }
  .hero-mascot { max-height: 250px; }
  .byte-callout { flex-direction: column; align-items: center; text-align: center; }
  .byte-callout img { width: 70px; }
  .tutorial-card:hover { transform: translateY(-5px) scale(1); }
  .tool-grid { grid-template-columns: 1fr 1fr; }
  .mnemonic-box .mnemonic-phrase { font-size: 1.1rem; }
}
@media (max-width: 480px) {
  .hero-title { font-size: 1.9rem; }
  .tool-grid { grid-template-columns: 1fr; }
}

/* ===== AI Prompt Box ===== */
.ai-prompt-box {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  border: 1px solid #6f42c1;
  border-radius: 16px;
  padding: 24px;
  margin: 2rem 0;
  color: #cdd6f4;
}
.ai-prompt-box h5 { color: #b4befe; }
.ai-prompt-text {
  background: rgba(0,0,0,0.3);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 10px;
  padding: 16px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  line-height: 1.7;
  white-space: pre-wrap;
  color: #a6e3a1;
}
.btn-copy-prompt {
  background: #6f42c1;
  color: #fff;
  border: none;
  padding: 6px 16px;
  border-radius: 8px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-copy-prompt:hover { background: #7c3aed; }
.btn-copy-prompt.copied { background: var(--ieb-accent); }

/* ===== Download Script Button ===== */
.btn-download-script {
  background: linear-gradient(135deg, var(--ieb-primary) 0%, var(--ieb-secondary) 100%);
  color: #fff;
  border: none;
  padding: 8px 20px;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.btn-download-script:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(13,110,253,0.3);
}
.download-bar {
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
  border-radius: 12px;
  padding: 16px 20px;
  margin: 1.5rem 0;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}
.download-bar .download-label {
  font-weight: 700;
  font-size: 0.9rem;
  margin-right: auto;
}

/* ===== Troubleshooting / Error Boxes ===== */
.error-box {
  border: 1px solid #f87171;
  border-left: 5px solid #ef4444;
  border-radius: 12px;
  padding: 20px;
  margin: 1.5rem 0;
  background: linear-gradient(135deg, #fef2f2 0%, #fff1f2 100%);
}
[data-bs-theme="dark"] .error-box {
  background: linear-gradient(135deg, #450a0a 0%, #7f1d1d 100%);
  border-color: #991b1b;
  color: #fecaca;
}
.error-box code {
  background: rgba(239,68,68,0.15);
  color: #dc2626;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85rem;
}
[data-bs-theme="dark"] .error-box code {
  background: rgba(239,68,68,0.25);
  color: #fca5a5;
}
.error-box h6 { color: #dc2626; font-weight: 700; }
[data-bs-theme="dark"] .error-box h6 { color: #fca5a5; }

/* ===== Organism-Specific Callouts ===== */
.organism-callout {
  border-radius: 12px;
  padding: 20px;
  margin: 1rem 0;
  border: 1px solid var(--ieb-border);
}
.organism-callout.plant {
  background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
  border-color: #34d399;
}
.organism-callout.animal {
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
  border-color: #60a5fa;
}
.organism-callout.microbe {
  background: linear-gradient(135deg, #fdf4ff 0%, #fae8ff 100%);
  border-color: #c084fc;
}
[data-bs-theme="dark"] .organism-callout.plant { background: linear-gradient(135deg, #022c22 0%, #064e3b 100%); }
[data-bs-theme="dark"] .organism-callout.animal { background: linear-gradient(135deg, #172554 0%, #1e3a5f 100%); }
[data-bs-theme="dark"] .organism-callout.microbe { background: linear-gradient(135deg, #2e1065 0%, #3b0764 100%); }

/* ===== Collapsible Sections — Smooth ===== */
.collapsible-header {
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
  border-radius: 14px;
  padding: 16px 20px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 700;
  transition: all 0.3s;
  margin-top: 1rem;
  user-select: none;
}
.collapsible-header:hover {
  border-color: var(--ieb-primary);
  box-shadow: var(--ieb-shadow-sm);
  transform: translateX(4px);
}
.collapsible-header .collapse-icon { transition: transform 0.3s; }
.collapsible-body {
  display: none;
  padding: 20px;
  border: 1px solid var(--ieb-border);
  border-top: none;
  border-radius: 0 0 14px 14px;
  background: var(--ieb-card-bg);
  animation: slideDown 0.3s ease;
}
.collapsible-body.show { display: block; }
@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== Demo Output Box ===== */
.demo-output {
  background: #0d1117;
  border: 1px solid #30363d;
  border-radius: 12px;
  padding: 20px;
  margin: 1.5rem 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.82rem;
  line-height: 1.7;
  color: #c9d1d9;
  overflow-x: auto;
}
.demo-output .output-label {
  color: #58a6ff;
  font-weight: 700;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
  display: block;
}

/* ===== Founder Card ===== */
.founder-card {
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
  border-radius: 16px;
  padding: 30px;
  text-align: center;
}
.founder-card img {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  border: 3px solid var(--ieb-primary);
  object-fit: cover;
}
.founder-links a {
  color: var(--ieb-text);
  font-size: 1.3rem;
  transition: color 0.2s;
}
.founder-links a:hover { color: var(--ieb-primary); }

/* ===== Tool Comparison Grid — Interactive ===== */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 14px;
  margin: 1.5rem 0;
}
.tool-card {
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
  border-radius: 14px;
  padding: 16px;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}
.tool-card::after {
  content: '';
  position: absolute;
  top: 0; left: -100%; width: 100%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.05), transparent);
  transition: left 0.6s;
}
.tool-card:hover::after { left: 100%; }
.tool-card:hover {
  border-color: var(--ieb-primary);
  transform: translateY(-4px);
  box-shadow: var(--ieb-shadow-md), 0 0 20px rgba(13,110,253,0.06);
}
.tool-card h6 { font-weight: 700; margin-bottom: 6px; }
.tool-card .tool-tag {
  font-size: 0.68rem;
  padding: 2px 8px;
  border-radius: 10px;
  background: rgba(13,110,253,0.1);
  color: var(--ieb-primary);
  display: inline-block;
  transition: all 0.2s;
}
.tool-card:hover .tool-tag {
  background: var(--ieb-primary);
  color: #fff;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--ieb-body-bg); }
::-webkit-scrollbar-thumb { background: var(--ieb-text-muted); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--ieb-primary); }

/* ===== Link Glow on Hover ===== */
.tutorial-content a:not(.btn) {
  color: var(--ieb-primary);
  text-decoration: none;
  border-bottom: 1px dashed rgba(13,110,253,0.3);
  transition: all 0.2s;
}
.tutorial-content a:not(.btn):hover {
  border-bottom-color: var(--ieb-primary);
  text-shadow: 0 0 10px var(--ieb-glow-primary);
}

/* ===== Section heading animation ===== */
.tutorial-content section h2 {
  transition: all 0.3s;
}
.tutorial-content section h2:hover {
  transform: translateX(4px);
}

/* ===== Search Input Enhancement ===== */
#tutorial-search {
  border-radius: 50px;
  padding: 12px 20px;
  border: 2px solid var(--ieb-border);
  transition: all 0.3s;
  font-size: 0.95rem;
}
#tutorial-search:focus {
  border-color: var(--ieb-primary);
  box-shadow: 0 0 0 4px var(--ieb-glow-primary);
}
.input-group-text {
  border-radius: 50px 0 0 50px !important;
  border: 2px solid var(--ieb-border);
  border-right: none;
}
#tutorial-search:focus ~ .input-group-text,
#tutorial-search:focus + .input-group-text { border-color: var(--ieb-primary); }

/* ===== Directory Tree Component ===== */
.dir-tree {
  background: var(--ieb-code-bg);
  color: var(--ieb-code-text);
  border-radius: 12px;
  padding: 1.25rem 1.5rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.82rem;
  line-height: 1.85;
  border: 1px solid rgba(255,255,255,0.06);
  overflow-x: auto;
  margin-bottom: 1rem;
}
.dir-tree .dir-label {
  display: flex;
  align-items: flex-start;
  gap: 0.4rem;
}
.dir-tree .tree-folder { color: #89b4fa; font-weight: 600; }
.dir-tree .tree-file   { color: #a6e3a1; }
.dir-tree .tree-note   { color: #9399b2; font-style: italic; font-size: 0.78rem; }
.dir-tree .tree-active { color: #f9e2af; font-weight: 700; }
.dir-tree .tree-output { color: #cba6f7; }
.dir-tree-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  color: #fff;
}
.dir-tree-header i { color: var(--ieb-accent); font-size: 1rem; }

/* ===== Command Explain Box ===== */
.cmd-explain {
  background: linear-gradient(135deg, rgba(13,110,253,0.06) 0%, rgba(32,201,151,0.06) 100%);
  border: 1px solid rgba(13,110,253,0.18);
  border-left: 4px solid var(--ieb-primary);
  border-radius: 0 10px 10px 0;
  padding: 1rem 1.25rem;
  margin-top: 0.6rem;
  margin-bottom: 1rem;
  font-size: 0.88rem;
}
.cmd-explain-title {
  font-weight: 700;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ieb-primary);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.cmd-explain table { width: 100%; border-collapse: collapse; margin: 0; }
.cmd-explain table td {
  padding: 0.3rem 0.5rem;
  vertical-align: top;
  border-bottom: 1px solid var(--ieb-border);
  font-size: 0.84rem;
}
.cmd-explain table tr:last-child td { border-bottom: none; }
.cmd-explain table td:first-child {
  font-family: 'JetBrains Mono', monospace;
  color: var(--ieb-accent);
  font-weight: 600;
  white-space: nowrap;
  width: 35%;
  font-size: 0.8rem;
}
.cmd-explain table td:last-child { color: var(--ieb-text); }
.cmd-explain .cmd-emoji { font-size: 1rem; margin-right: 0.2rem; }

/* ===== Fun Tip Box ===== */
.fun-tip {
  background: rgba(249,226,175,0.1);
  border: 1px solid rgba(249,226,175,0.3);
  border-radius: 10px;
  padding: 0.85rem 1.1rem;
  margin-top: 0.75rem;
  font-size: 0.87rem;
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
}
.fun-tip .fun-tip-icon { font-size: 1.3rem; line-height: 1.2; flex-shrink: 0; }
.fun-tip strong { color: #f9e2af; }
[data-bs-theme="light"] .fun-tip strong { color: #854d0e; }
[data-bs-theme="light"] .fun-tip { background: rgba(251,191,36,0.08); border-color: rgba(251,191,36,0.3); }

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 30px; right: 30px;
  width: 48px; height: 48px;
  border-radius: 50%;
  background: var(--ieb-gradient);
  color: #fff;
  border: none;
  font-size: 1.2rem;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.4s;
  z-index: 999;
  box-shadow: 0 4px 20px var(--ieb-glow-primary);
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
}
.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px var(--ieb-glow-primary);
}

/* ===== Navbar Logo — image only, no text ===== */
.navbar-logo {
  height: 64px;
  width: auto;
  border-radius: 10px;
  object-fit: contain;
  transition: transform 0.35s cubic-bezier(0.34,1.56,0.64,1), filter 0.3s;
  display: block;
}
.navbar-brand {
  padding: 4px 0;
}
.navbar-brand:hover .navbar-logo {
  transform: scale(1.08);
  filter: drop-shadow(0 0 10px rgba(13,110,253,0.5));
}
.brand-indian, .brand-elucid, .brand-biology {
  display: none;
}

/* ===== Page Loader ===== */
#page-loader {
  position: fixed;
  inset: 0;
  z-index: 99999;
  background: #0a0f1e;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 28px;
  transition: opacity 0.5s ease, visibility 0.5s ease;
}
#page-loader.loader-hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}
/* Circular spinner ring + logo in centre */
.loader-ring-wrap {
  position: relative;
  width: 120px;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: loaderBounceIn 0.55s cubic-bezier(0.34,1.56,0.64,1) both;
}
.loader-ring-svg {
  position: absolute;
  inset: 0;
  width: 120px;
  height: 120px;
  animation: loaderSpin 1.4s linear infinite;
}
.loader-ring-track {
  fill: none;
  stroke: rgba(255,255,255,0.06);
  stroke-width: 4;
}
.loader-ring-arc {
  fill: none;
  stroke: url(#ringGrad);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-dasharray: 200;
  stroke-dashoffset: 60;
}
.loader-logo-img {
  width: 72px;
  height: 72px;
  border-radius: 14px;
  object-fit: contain;
  position: relative;
  z-index: 2;
  background: #fff;
  padding: 4px;
  box-shadow: 0 0 24px rgba(13,110,253,0.35);
}
.loader-site-name {
  font-family: 'Inter', sans-serif;
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: 0.01em;
  animation: loaderFadePulse 1.8s ease-in-out infinite;
}
.loader-site-name .li { color: #ff9933; }
.loader-site-name .le { color: #4d9fff; }
.loader-site-name .lb { color: #20c997; }
.loader-sub {
  font-size: 0.72rem;
  color: rgba(255,255,255,0.35);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-family: 'JetBrains Mono', monospace;
  animation: loaderFadePulse 1.8s ease-in-out 0.3s infinite;
}
@keyframes loaderSpin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}
@keyframes loaderBounceIn {
  from { opacity: 0; transform: scale(0.6); }
  to   { opacity: 1; transform: scale(1); }
}
@keyframes loaderFadePulse {
  0%, 100% { opacity: 0.45; }
  50%      { opacity: 1;    }
}

/* ===== Founder Avatar (initials circle) ===== */
.founder-avatar {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  background: linear-gradient(135deg, #0d6efd 0%, #20c997 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Inter', sans-serif;
  font-size: 2.2rem;
  font-weight: 900;
  color: #fff;
  letter-spacing: 2px;
  box-shadow: 0 8px 32px rgba(13,110,253,0.35), 0 0 0 4px rgba(13,110,253,0.15);
  flex-shrink: 0;
  user-select: none;
}

/* ===== Footer Logo ===== */
.footer-logo {
  height: 52px;
  width: auto;
  border-radius: 10px;
  object-fit: contain;
  filter: brightness(1) drop-shadow(0 2px 8px rgba(13,110,253,0.3));
  transition: transform 0.3s, filter 0.3s;
}
.footer-logo:hover {
  transform: scale(1.06);
  filter: brightness(1.05) drop-shadow(0 4px 16px rgba(13,110,253,0.5));
}

/* ===== Visitor Counter Badges ===== */
.tutorial-visitor-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.78rem;
  font-weight: 600;
  color: rgba(255,255,255,0.75);
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 20px;
  padding: 4px 12px;
  margin-top: 8px;
  backdrop-filter: blur(6px);
}
.tutorial-visitor-badge i {
  color: #20c997;
  font-size: 0.8rem;
}
/* Homepage stat bar views number */
.visitor-count-num {
  font-size: 1.6rem !important;
  font-weight: 900;
  background: linear-gradient(135deg, #0d6efd, #20c997);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== HOMEPAGE REDESIGN ADDITIONS ===== */

/* ---- Hero glow ring + chip links ---- */
.hero-glow-ring {
  position: absolute;
  inset: -20px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(13,110,253,0.18) 0%, transparent 70%);
  animation: pulseGlow 4s ease-in-out infinite;
  pointer-events: none;
}
.hero-mascot-wrapper {
  display: inline-block;
}
.hero-chip {
  display: inline-block;
  padding: 5px 14px;
  font-size: 0.78rem;
  font-weight: 600;
  border-radius: 30px;
  background: rgba(255,255,255,0.1);
  color: rgba(255,255,255,0.85);
  border: 1px solid rgba(255,255,255,0.2);
  text-decoration: none;
  transition: all 0.25s;
  backdrop-filter: blur(8px);
}
.hero-chip:hover {
  background: var(--ieb-primary);
  color: #fff;
  border-color: var(--ieb-primary);
  transform: translateY(-2px);
}

/* ---- Stats Bar ---- */
.stats-bar {
  background: var(--ieb-card-bg);
  border-top: 1px solid var(--ieb-border);
  border-bottom: 1px solid var(--ieb-border);
}
.stats-row { gap: 0; }
.stat-item {
  padding: 20px 12px;
  border-right: 1px solid var(--ieb-border);
}
.stat-item:last-child { border-right: none; }
.stat-label {
  font-size: 0.8rem;
  color: var(--ieb-text-muted);
  font-weight: 500;
  margin-top: 2px;
}

/* ---- Ad Slots ---- */
.ad-slot-leaderboard,
.ad-slot-rectangle {
  padding: 16px 0;
  text-align: center;
}
.ad-label {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ieb-text-muted);
  margin-bottom: 6px;
  font-weight: 500;
}
.ad-placeholder-leaderboard {
  width: 100%;
  max-width: 728px;
  height: 90px;
  border: 2px dashed var(--ieb-border);
  border-radius: 8px;
  margin: 0 auto;
  background: var(--ieb-body-bg);
  font-size: 0.78rem;
}
.ad-placeholder-rect {
  width: 300px;
  height: 250px;
  border: 2px dashed var(--ieb-border);
  border-radius: 8px;
  margin: 0 auto;
  background: var(--ieb-body-bg);
  font-size: 0.78rem;
}

/* ---- Section Eyebrow ---- */
.section-eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ieb-primary);
  background: rgba(13,110,253,0.08);
  padding: 4px 14px;
  border-radius: 20px;
  border: 1px solid rgba(13,110,253,0.18);
}

/* ---- Category Cards ---- */
.cat-card {
  display: block;
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
  border-radius: 18px;
  padding: 24px 18px 20px;
  text-align: center;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  height: 100%;
  position: relative;
  overflow: hidden;
}
.cat-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--ieb-gradient);
  opacity: 0;
  transition: opacity 0.3s;
  z-index: 0;
}
.cat-card:hover::before { opacity: 0.04; }
.cat-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--ieb-shadow-lg);
  border-color: var(--ieb-primary);
}
.cat-card > * { position: relative; z-index: 1; }
.cat-icon {
  width: 60px;
  height: 60px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin: 0 auto 14px;
  transition: transform 0.3s;
}
.cat-card:hover .cat-icon { transform: scale(1.12) rotate(-6deg); }
.cat-title {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--ieb-text);
  margin-bottom: 4px;
}
.cat-sub {
  font-size: 0.76rem;
  color: var(--ieb-text-muted);
  margin-bottom: 8px;
}
.cat-count {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--ieb-primary);
  background: rgba(13,110,253,0.09);
  padding: 2px 10px;
  border-radius: 20px;
}

/* ---- Featured Tutorial feat-tag ---- */
.feat-tag {
  display: inline-block;
  padding: 2px 9px;
  font-size: 0.7rem;
  font-weight: 600;
  border-radius: 12px;
  background: rgba(13,110,253,0.1);
  color: var(--ieb-primary);
  border: 1px solid rgba(13,110,253,0.15);
}
.feat-tag.tag-live {
  background: rgba(29,111,66,0.1);
  color: #1d6f42;
  border-color: rgba(29,111,66,0.2);
}
[data-bs-theme="dark"] .feat-tag.tag-live { color: #4ade80; background: rgba(74,222,128,0.1); }

/* ---- Live Spreadsheet Preview Box ---- */
.live-sheet-preview {
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
}
.dot-red   { width: 12px; height: 12px; border-radius: 50%; background: #ff5f57; display: inline-block; }
.dot-yellow{ width: 12px; height: 12px; border-radius: 50%; background: #febc2e; display: inline-block; margin-left: 6px; }
.dot-green { width: 12px; height: 12px; border-radius: 50%; background: #28c840; display: inline-block; margin-left: 6px; }
.preview-table th { font-size: 0.78rem; font-weight: 700; }
.preview-table td { font-size: 0.82rem; }
.editable-preview {
  background: rgba(255,232,91,0.18);
  font-weight: 600;
  color: #92400e;
  border-left: 2px solid #eab308 !important;
}
[data-bs-theme="dark"] .editable-preview { color: #fde68a; background: rgba(234,179,8,0.12); }
.formula-preview { font-family: 'JetBrains Mono', monospace; font-size: 0.78rem !important; }
.feature-list { padding: 0; }
.feature-list li { padding: 5px 0; font-size: 0.95rem; }

/* ---- Byte Feature Cards ---- */
.byte-feature-card {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
  border-radius: 14px;
  padding: 16px;
  transition: all 0.3s;
}
.byte-feature-card:hover {
  border-color: var(--ieb-primary);
  box-shadow: var(--ieb-shadow-sm);
  transform: translateY(-3px);
}

/* ---- About Stats Panel ---- */
.about-stats-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.about-stat {
  background: var(--ieb-card-bg);
  border: 1px solid var(--ieb-border);
  border-radius: 14px;
  padding: 20px;
  text-align: center;
  transition: all 0.3s;
}
.about-stat:hover { border-color: var(--ieb-primary); transform: translateY(-4px); box-shadow: var(--ieb-shadow-sm); }
.as-num {
  display: block;
  font-size: 2rem;
  font-weight: 900;
  background: var(--ieb-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.1;
}
.as-label {
  display: block;
  font-size: 0.78rem;
  color: var(--ieb-text-muted);
  margin-top: 4px;
}

/* ---- Founder Avatar Ring ---- */
.founder-avatar-ring {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  background: var(--ieb-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 3px;
}
.founder-avatar-ring img {
  border-radius: 50%;
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: var(--ieb-card-bg);
  border: 3px solid var(--ieb-card-bg);
}
.founder-social {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: rgba(13,110,253,0.1);
  color: var(--ieb-primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  text-decoration: none;
  transition: all 0.25s;
  border: 1px solid rgba(13,110,253,0.15);
}
.founder-social:hover {
  background: var(--ieb-primary);
  color: #fff;
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(13,110,253,0.3);
}

/* ---- Footer links ---- */
.footer-links li { margin-bottom: 8px; }
.footer-links a {
  color: rgba(255,255,255,0.6);
  text-decoration: none;
  font-size: 0.85rem;
  transition: color 0.2s;
}
.footer-links a:hover { color: #fff; }

/* ================================================================
   NEWS HUB SECTION
   ================================================================ */

/* Section header pill */
.hub-eyebrow {
  display: inline-block;
  background: linear-gradient(135deg, var(--ieb-primary), var(--ieb-accent));
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  padding: 4px 14px;
  border-radius: 999px;
  margin-bottom: 10px;
}

/* News card */
.news-card {
  background: var(--ieb-glass);
  border: 1px solid var(--ieb-glass-border);
  border-radius: 16px;
  overflow: hidden;
  transition: transform 0.22s, box-shadow 0.22s;
  height: 100%;
}
.news-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 36px rgba(13,110,253,0.12);
}
.news-card-label {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 10px;
}
.news-label-new      { background: rgba(25,200,120,0.15); color: #19c878; }
.news-label-feature  { background: rgba(13,110,253,0.13); color: var(--ieb-primary); }
.news-label-news     { background: rgba(253,126,20,0.13); color: #fd7e14; }
.news-label-tutorial { background: rgba(111,66,193,0.13); color: #6f42c1; }
.news-label-ai       { background: rgba(83,52,131,0.15);  color: #533483; }

.news-card-date {
  font-size: 0.75rem;
  color: var(--ieb-muted);
  margin-bottom: 6px;
}
.news-card-title {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 8px;
  color: var(--ieb-text);
}
.news-card-body { font-size: 0.875rem; color: var(--ieb-muted); }
.news-card-link {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--ieb-primary);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: 12px;
  transition: gap 0.18s;
}
.news-card-link:hover { gap: 8px; color: var(--ieb-primary); }

/* Contributor of the Month card */
.cotm-card {
  background: linear-gradient(135deg, rgba(13,110,253,0.07) 0%, rgba(32,201,151,0.07) 100%);
  border: 1px solid rgba(13,110,253,0.18);
  border-radius: 20px;
  padding: 32px;
}
.cotm-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--ieb-primary), var(--ieb-accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  font-weight: 800;
  color: #fff;
  flex-shrink: 0;
  box-shadow: 0 6px 20px rgba(13,110,253,0.3);
}
.cotm-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: linear-gradient(135deg, #ffd700, #ffb700);
  color: #1a1a2e;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 8px;
}

/* Pinned feature banner */
.feature-banner {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  border-radius: 20px;
  padding: 36px 40px;
  position: relative;
  overflow: hidden;
}
.feature-banner::before {
  content: '';
  position: absolute;
  top: -60px; right: -60px;
  width: 220px; height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(13,110,253,0.25), transparent 70%);
  pointer-events: none;
}
.feature-banner-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,255,255,0.12);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 14px;
}

/* New additions list */
.new-addition-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--ieb-glass-border);
}
.new-addition-item:last-child { border-bottom: none; }
.new-addition-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

/* ================================================================
   RESPONSIVE — Mobile-first overrides
   ================================================================ */

/* ----- Tablet & below (≤ 991px) ----- */
@media (max-width: 991.98px) {

  /* Navbar */
  .navbar-logo { height: 44px; }
  .navbar-collapse {
    background: var(--ieb-glass);
    backdrop-filter: blur(20px);
    border-top: 1px solid var(--ieb-glass-border);
    border-radius: 0 0 12px 12px;
    padding: 12px 8px;
    margin-top: 6px;
  }
  .navbar .nav-link { padding: 10px 14px; font-size: 0.95rem; }
  .navbar .dropdown-menu {
    border: none;
    box-shadow: none;
    background: rgba(0,0,0,0.04);
    padding-left: 12px;
  }
  [data-bs-theme="dark"] .navbar .dropdown-menu { background: rgba(255,255,255,0.04); }
  .navbar .dropdown-menu .dropdown-item { font-size: 0.88rem; padding: 7px 12px; }
  .theme-toggle { margin: 8px 14px 4px; }

  /* Hero */
  .hero-section { padding: 100px 0 60px; text-align: center; }
  .hero-title { font-size: 2.2rem; }
  .hero-subtitle { font-size: 1rem; }
  .hero-mascot-wrapper { margin-top: 32px; }
  .hero-mascot { max-height: 200px; }
  .hero-glow-ring { inset: -10px; }

  /* Tutorial pages hero */
  .tutorial-hero { padding: 90px 0 40px; }
  .tutorial-hero h1 { font-size: 1.75rem; }
  .tutorial-hero .lead { font-size: 0.95rem; }
  .tutorial-hero .col-lg-4 { display: none !important; }

  /* TOC sidebar — hide on tablet, show as top bar */
  .toc-sidebar { display: none; }
  .col-lg-9 { width: 100%; max-width: 100%; flex: 0 0 100%; }

  /* Code blocks */
  .code-block-wrapper pre {
    font-size: 0.78rem;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  /* Live spreadsheet */
  .live-sheet { overflow-x: auto; -webkit-overflow-scrolling: touch; }
}

/* ----- Mobile (≤ 767px) ----- */
@media (max-width: 767.98px) {

  /* Navbar */
  .navbar-logo { height: 38px; }
  .navbar-brand { padding: 2px 0; }

  /* Hero */
  .hero-section { padding: 88px 0 48px; }
  .hero-title { font-size: 1.85rem; line-height: 1.2; }
  .hero-subtitle { font-size: 0.92rem; }
  .hero-cta-group .btn { font-size: 0.9rem; padding: 10px 20px; width: 100%; }
  .hero-cta-group { flex-direction: column; gap: 10px !important; }
  .hero-chip { font-size: 0.72rem; padding: 4px 10px; }
  .hero-mascot { max-height: 180px; }

  /* Stats bar */
  .stats-row { display: grid; grid-template-columns: 1fr 1fr; }
  .stats-row .stat-item {
    border-right: none !important;
    border-bottom: 1px solid var(--ieb-border);
    padding: 16px 8px;
  }
  .stats-row .stat-item:nth-child(odd) { border-right: 1px solid var(--ieb-border) !important; }
  .stats-row .stat-item:last-child,
  .stats-row .stat-item:nth-last-child(2):nth-child(odd) { border-bottom: none; }
  .stat-number { font-size: 1.6rem; }

  /* Category cards */
  .cat-card { padding: 14px 10px; }
  .cat-card .cat-icon { font-size: 1.8rem; }
  .cat-card h6 { font-size: 0.8rem; }

  /* Tutorial cards */
  .tut-card { margin-bottom: 4px; }
  .tut-card .card-body { padding: 16px; }
  .tut-card h5 { font-size: 0.95rem; }

  /* Featured tutorials section */
  .feat-tag { font-size: 0.68rem; padding: 2px 8px; }

  /* About / founder */
  .founder-card { padding: 24px 16px; }
  .founder-avatar { width: 88px; height: 88px; font-size: 1.8rem; }
  .about-stats-panel { grid-template-columns: 1fr 1fr; gap: 12px; }
  .as-num { font-size: 1.6rem; }

  /* Tutorial page content */
  .tutorial-hero { padding: 80px 0 36px; }
  .tutorial-hero h1 { font-size: 1.5rem; }
  .tutorial-hero .badge { font-size: 0.72rem; padding: 5px 10px; }
  .tutorial-content { font-size: 0.92rem; }
  .section-divider { font-size: 1.2rem; }

  /* Code blocks */
  .code-block-wrapper { margin: 16px -4px; border-radius: 10px; }
  .code-block-wrapper pre { font-size: 0.74rem; padding: 14px 12px; }
  .code-block-header { font-size: 0.78rem; padding: 8px 12px; flex-wrap: wrap; gap: 6px; }
  .btn-copy { font-size: 0.72rem; padding: 3px 10px; }

  /* Byte callout */
  .byte-callout { flex-direction: column; align-items: flex-start; gap: 10px; padding: 14px; }
  .byte-callout img { width: 48px; height: 48px; }

  /* Formula explain boxes */
  .formula-explain { padding: 14px; }
  .fe-equation { font-size: 0.88rem; overflow-x: auto; white-space: nowrap; }
  .fe-terms { font-size: 0.82rem; }

  /* Param tables */
  .param-table { overflow-x: auto; -webkit-overflow-scrolling: touch; }
  .param-table table { font-size: 0.8rem; min-width: 420px; }

  /* Download bar */
  .download-bar { flex-wrap: wrap; gap: 8px; }
  .btn-download-script { font-size: 0.78rem; padding: 6px 14px; }

  /* Footer */
  .site-footer { padding: 40px 0 24px; }
  .site-footer .row > div { text-align: center; }
  .site-footer .d-flex { justify-content: center !important; }
  .footer-logo { height: 42px; }

  /* Loader */
  .loader-ring-wrap { width: 96px; height: 96px; }
  .loader-ring-svg { width: 96px; height: 96px; }
  .loader-logo-img { width: 58px; height: 58px; }
  .loader-site-name { font-size: 1rem; }

  /* Progress tracker */
  .progress-tracker { height: 3px; }

  /* Back to top */
  .back-to-top { width: 40px; height: 40px; font-size: 1rem; bottom: 16px; right: 16px; }

  /* Visitor badge */
  .tutorial-visitor-badge { font-size: 0.72rem; padding: 3px 10px; }

  /* Founder card social links */
  .founder-social { font-size: 1.1rem; }
}

/* ----- Small phones (≤ 480px) ----- */
@media (max-width: 480px) {
  .hero-title { font-size: 1.6rem; }
  .hero-cta-group .btn-lg { font-size: 0.85rem; }
  .about-stats-panel { grid-template-columns: 1fr 1fr; gap: 8px; }
  .hero-chip { font-size: 0.68rem; padding: 3px 8px; }
  .tutorial-hero h1 { font-size: 1.3rem; }
  .code-block-wrapper pre { font-size: 0.7rem; }
  .navbar-logo { height: 34px; }
  .fe-equation { font-size: 0.8rem; }
  .section-divider { font-size: 1.1rem; }
  .stat-number { font-size: 1.4rem; }
  .founder-avatar { width: 76px; height: 76px; font-size: 1.5rem; }
}