/* ProgrammingVideoTutorials.com - Modern High-Performance Design System */
:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  --bg-primary: #0b0f19;
  --bg-secondary: #111827;
  --bg-tertiary: #1f2937;
  --bg-card: rgba(17, 24, 39, 0.85);
  --bg-card-hover: rgba(31, 41, 55, 0.95);
  --header-bg: rgba(11, 15, 25, 0.92);
  
  --text-primary: #f9fafb;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --text-color: #f9fafb;
  --bg-input: #1e293b;
  
  --border-color: #374151;
  --border-subtle: #1f2937;
  
  --brand-primary: #3b82f6;
  --brand-hover: #60a5fa;
  --brand-glow: rgba(59, 130, 246, 0.25);
  --brand-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 50%, #ec4899 100%);
  
  --code-bg: #030712;
  --code-header: #111827;
  --code-text: #e2e8f0;
  
  --ad-bg: rgba(17, 24, 39, 0.5);
  --ad-border: #2d3748;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-glow: 0 0 25px rgba(59, 130, 246, 0.15);
  
  --container-max: 1200px;
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;
  --header-bg: rgba(255, 255, 255, 0.95);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-color: #0f172a;
  --bg-input: #ffffff;
  
  --border-color: #e2e8f0;
  --border-subtle: #f1f5f9;
  
  --brand-primary: #2563eb;
  --brand-hover: #1d4ed8;
  --brand-glow: rgba(37, 99, 235, 0.15);
  
  --code-bg: #0f172a;
  --code-header: #1e293b;
  --code-text: #f8fafc;
  
  --ad-bg: #f1f5f9;
  --ad-border: #cbd5e1;
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  max-width: 100vw;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  max-width: 100vw;
}

a {
  color: var(--brand-primary);
  text-decoration: none;
  transition: color 0.15s ease;
}

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

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

/* Form Elements & Inputs */
input, select, textarea {
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--text-primary);
  background-color: var(--bg-input, #1e293b);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

input:focus, select:focus, textarea:focus {
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 2px var(--brand-glow);
}

select {
  cursor: pointer;
  background-color: #1e293b;
  color: #f8fafc;
}

select option, select optgroup {
  background-color: #0f172a;
  color: #f8fafc;
  padding: 8px 12px;
}

[data-theme="light"] select {
  background-color: #ffffff;
  color: #0f172a;
  border-color: #cbd5e1;
}

[data-theme="light"] select option, [data-theme="light"] select optgroup {
  background-color: #ffffff;
  color: #0f172a;
}

/* Layout Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.25rem;
  gap: 1rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
  text-decoration: none;
  flex-shrink: 0;
}

.brand-logo .logo-icon {
  width: 2.25rem;
  height: 2.25rem;
  background: var(--brand-gradient);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.1rem;
}

.brand-text-full {
  display: inline;
}

.brand-text-short {
  display: none;
}

@media (max-width: 680px) {
  .brand-text-full {
    display: none;
  }
  .brand-text-short {
    display: inline;
  }
}

.brand-logo span span {
  color: var(--brand-primary);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  list-style: none;
  flex-wrap: nowrap;
}

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.92rem;
  padding: 0.45rem 0.65rem;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
  white-space: nowrap;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--text-primary);
  background-color: var(--bg-tertiary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.lang-switch-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  font-weight: 700;
  text-decoration: none;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.lang-switch-btn:hover {
  background: var(--border-color);
  color: var(--brand-hover);
}

.lang-switch-btn .lang-switch-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}

.theme-toggle-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.5rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
  min-width: 38px;
  min-height: 38px;
}

.theme-toggle-btn:hover {
  background: var(--border-color);
}

.mobile-menu-btn {
  display: none;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 1.25rem;
  cursor: pointer;
  min-width: 38px;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
}

/* Hero Section */
.hero {
  padding: 5rem 0 3.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-ambient-glow {
  position: absolute;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: min(1000px, 90vw);
  height: 480px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.18) 0%, rgba(139, 92, 246, 0.1) 40%, transparent 70%);
  pointer-events: none;
  z-index: 0;
  filter: blur(40px);
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.4rem 1.1rem;
  border-radius: var(--radius-full);
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.35);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--brand-hover);
  font-size: 0.875rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: #10b981;
  box-shadow: 0 0 10px #10b981;
  display: inline-block;
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.2); opacity: 1; box-shadow: 0 0 14px #10b981; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}

.hero h1 .gradient-text {
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  max-width: 760px;
  margin: 0 auto 2rem;
  line-height: 1.6;
}

/* Hero Quick Navigation Hub Chips */
.hero-quick-chips {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin: 1.75rem 0 2.25rem;
}

.quick-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 700;
  text-decoration: none;
  transition: all 0.2s ease;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.quick-chip:hover {
  transform: translateY(-2px);
}

.chip-quant {
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(16, 185, 129, 0.35);
  color: #10b981;
}
.chip-quant:hover {
  background: rgba(16, 185, 129, 0.22);
  border-color: #10b981;
  box-shadow: 0 0 15px rgba(16, 185, 129, 0.25);
}

.chip-biz {
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.35);
  color: #3b82f6;
}
.chip-biz:hover {
  background: rgba(59, 130, 246, 0.22);
  border-color: #3b82f6;
  box-shadow: 0 0 15px rgba(59, 130, 246, 0.25);
}

.chip-tools {
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.35);
  color: #f59e0b;
}
.chip-tools:hover {
  background: rgba(245, 158, 11, 0.22);
  border-color: #f59e0b;
  box-shadow: 0 0 15px rgba(245, 158, 11, 0.25);
}

.chip-vibe {
  background: rgba(168, 85, 247, 0.12);
  border: 1px solid rgba(168, 85, 247, 0.35);
  color: #c084fc;
}
.chip-vibe:hover {
  background: rgba(168, 85, 247, 0.22);
  border-color: #c084fc;
  box-shadow: 0 0 15px rgba(168, 85, 247, 0.25);
}

.chip-news {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
}
.chip-news:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--text-secondary);
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-num {
  font-size: clamp(1.75rem, 3vw, 2.2rem);
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.2;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 600;
  margin-top: 0.25rem;
}

/* Ergonomic Search Bar */
.search-container {
  max-width: 640px;
  margin: 0 auto;
  position: relative;
}

.search-input-wrap {
  display: flex;
  align-items: center;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 0.65rem 1.1rem;
  box-shadow: var(--shadow-md);
  transition: all 0.2s ease;
  gap: 0.5rem;
}

.search-input-wrap:focus-within {
  border-color: var(--brand-primary);
  box-shadow: var(--shadow-glow);
}

.search-icon {
  font-size: 1.15rem;
  color: var(--text-muted);
}

.search-input-wrap input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 1rem;
  outline: none;
}

.search-kbd-hint {
  font-size: 0.72rem;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.06);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
  white-space: nowrap;
}

/* Live Instant Search Dropdown */
.search-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  right: 0;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.55);
  max-height: 480px;
  overflow-y: auto;
  z-index: 1000;
  text-align: left;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.search-dropdown-section {
  padding: 0.4rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.search-dropdown-section:last-child {
  border-bottom: none;
}

.search-section-header {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  padding: 0.4rem 1rem 0.25rem 1rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.search-result-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.65rem 1rem;
  text-decoration: none;
  color: var(--text-primary);
  transition: all 0.15s ease;
  border-left: 3px solid transparent;
  cursor: pointer;
}

.search-result-item:hover,
.search-result-item.selected {
  background: rgba(59, 130, 246, 0.12);
  border-left-color: var(--brand-primary);
}

.search-item-main {
  flex: 1;
  min-width: 0;
}

.search-item-title {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.search-item-excerpt {
  font-size: 0.78rem;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-top: 0.15rem;
}

.search-item-badges {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
}

.search-item-badge {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.2rem 0.45rem;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.search-empty-state {
  padding: 2.25rem 1.5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.search-footer-hint {
  padding: 0.6rem 1rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  background: rgba(0, 0, 0, 0.25);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

/* Category Grid */
.section-title-wrap {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.section-title {
  font-size: 1.85rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-top: 0.25rem;
}

.category-pills {
  display: flex;
  gap: 0.75rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
  margin-bottom: 2.5rem;
}

.cat-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.2rem;
  border-radius: var(--radius-full);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 600;
  white-space: nowrap;
  transition: all 0.15s ease;
}

.cat-pill:hover, .cat-pill.active {
  background: var(--brand-primary);
  color: white;
  border-color: var(--brand-primary);
}

/* Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
  margin-bottom: 3.5rem;
}

@media (max-width: 1024px) {
  .cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .cards-grid {
    grid-template-columns: 1fr;
  }
}

.tutorial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

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

.card-media {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  overflow: hidden;
}

.card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.tutorial-card:hover .card-media img {
  transform: scale(1.05);
}

.card-badge {
  position: absolute;
  top: 0.75rem;
  left: 0.75rem;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  color: white;
  text-transform: uppercase;
}

.video-indicator {
  position: absolute;
  bottom: 0.75rem;
  right: 0.75rem;
  background: rgba(0, 0, 0, 0.8);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  color: white;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.card-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.card-title {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.card-excerpt {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 1.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-footer {
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
}

.card-author {
  color: var(--text-secondary);
  font-weight: 500;
}

.read-more-link {
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

/* ==========================================================================
   Monetization & Ad Container Architecture (Google AdSense + Verified Partner)
   Guaranteed Zero Cumulative Layout Shift (CLS)
   ========================================================================== */
.ad-slot-wrap {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 2.25rem 0;
  clear: both;
}

.ad-label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.ad-label::before,
.ad-label::after {
  content: "";
  display: inline-block;
  width: 14px;
  height: 1px;
  background: var(--border-color);
}

.ad-leaderboard {
  min-height: 90px;
  max-width: 728px;
  width: 100%;
  background: var(--ad-bg, rgba(15, 23, 42, 0.7));
  border: 1px dashed var(--ad-border, rgba(59, 130, 246, 0.35));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.ad-leaderboard:hover {
  border-color: rgba(59, 130, 246, 0.6);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

.ad-sidebar {
  min-height: 250px;
  max-width: 300px;
  width: 100%;
  background: var(--ad-bg, rgba(15, 23, 42, 0.7));
  border: 1px dashed var(--ad-border, rgba(59, 130, 246, 0.35));
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.ad-sidebar:hover {
  border-color: rgba(59, 130, 246, 0.6);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

.ad-in-content {
  min-height: 90px;
  max-width: 728px;
  width: 100%;
  background: var(--ad-bg, rgba(15, 23, 42, 0.7));
  border: 1px dashed var(--ad-border, rgba(59, 130, 246, 0.35));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
  margin: 2.25rem 0;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.ad-in-content:hover {
  border-color: rgba(59, 130, 246, 0.6);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

/* Fallback / Direct Sponsor Card */
.ad-fallback-card {
  width: 100%;
  height: 100%;
  min-height: inherit;
  padding: 0.85rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  text-decoration: none;
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.75) 0%, rgba(15, 23, 42, 0.9) 100%);
  box-sizing: border-box;
}

.ad-sidebar .ad-fallback-card {
  flex-direction: column;
  text-align: center;
  justify-content: center;
  padding: 1.75rem 1.25rem;
  gap: 1.25rem;
}

.ad-card-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.3rem 0.65rem;
  border-radius: 999px;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.35);
  color: #10b981;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  white-space: nowrap;
  flex-shrink: 0;
}

.ad-pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 8px #10b981;
  animation: adPulse 2s infinite ease-in-out;
}

@keyframes adPulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

.ad-card-body {
  flex: 1;
  min-width: 0;
}

.ad-card-title {
  font-size: 0.92rem;
  font-weight: 700;
  color: #f8fafc;
  line-height: 1.35;
  margin-bottom: 0.25rem;
}

.ad-card-sub {
  font-size: 0.78rem;
  color: var(--text-muted, #94a3b8);
  line-height: 1.45;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.ad-sidebar .ad-card-sub {
  white-space: normal;
}

.ad-card-cta {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.45rem 0.9rem;
  border-radius: 6px;
  background: rgba(59, 130, 246, 0.18);
  border: 1px solid rgba(59, 130, 246, 0.4);
  color: #38bdf8;
  font-size: 0.82rem;
  font-weight: 700;
  text-decoration: none;
  transition: all 0.2s;
  white-space: nowrap;
}

.ad-card-cta:hover {
  background: #3b82f6;
  color: #ffffff;
  border-color: #3b82f6;
  box-shadow: 0 4px 14px rgba(59, 130, 246, 0.4);
}

/* Hide fallback once Google AdSense loads an ad */
.ad-leaderboard:has(iframe) .ad-fallback-card,
.ad-sidebar:has(iframe) .ad-fallback-card,
.ad-in-content:has(iframe) .ad-fallback-card,
.ad-leaderboard:has(ins[data-ad-status="filled"]) .ad-fallback-card,
.ad-sidebar:has(ins[data-ad-status="filled"]) .ad-fallback-card,
.ad-in-content:has(ins[data-ad-status="filled"]) .ad-fallback-card {
  display: none !important;
}

.ad-leaderboard:has(iframe),
.ad-sidebar:has(iframe),
.ad-in-content:has(iframe) {
  border-style: solid;
  border-color: transparent;
  background: transparent;
}

/* Tutorial Page Layout */
.tutorial-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 2.5rem;
  padding: 3rem 0;
}

.tutorial-main {
  min-width: 0;
}

.tutorial-header {
  margin-bottom: 2rem;
}

.tutorial-breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.tutorial-title {
  font-size: clamp(1.8rem, 3.5vw, 2.7rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1rem;
}

.tutorial-meta-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.25rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.video-container {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: black;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  margin-bottom: 2.5rem;
}

.video-container iframe {
  width: 100%;
  height: 100%;
  border: none;
}

.objectives-box {
  background: rgba(59, 130, 246, 0.08);
  border-left: 4px solid var(--brand-primary);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  margin-bottom: 2.5rem;
}

.objectives-box h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.objectives-box ul {
  padding-left: 1.25rem;
}

.objectives-box li {
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.tutorial-content {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-secondary);
}

.tutorial-content h2 {
  color: var(--text-primary);
  font-size: 1.6rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem;
}

.tutorial-content p {
  margin-bottom: 1.25rem;
}

/* Code Blocks */
.code-block-wrap {
  background: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin: 1.5rem 0 2rem;
}

.code-header {
  background: var(--code-header);
  padding: 0.5rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-color);
}

.copy-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  padding: 0.25rem 0.6rem;
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.copy-btn:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.code-block-wrap pre {
  padding: 1.25rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--code-text);
  line-height: 1.6;
}

.callout-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  border-left: 4px solid #f59e0b;
}

/* Interactive Quiz */
.quiz-section {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin: 3rem 0;
}

.quiz-section h3 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
}

.quiz-card {
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin-bottom: 1.5rem;
}

.quiz-question {
  font-weight: 600;
  margin-bottom: 1rem;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.quiz-option-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  text-align: left;
  color: var(--text-primary);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.quiz-option-btn:hover {
  border-color: var(--brand-primary);
  background: var(--bg-card);
}

.quiz-option-btn.correct {
  background: rgba(16, 185, 129, 0.2);
  border-color: #10b981;
  color: #10b981;
}

.quiz-option-btn.wrong {
  background: rgba(239, 68, 68, 0.2);
  border-color: #ef4444;
  color: #ef4444;
}

.quiz-feedback {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  display: none;
}

/* FAQ Accordion */
.faq-section {
  margin: 3rem 0;
}

.faq-item {
  border-bottom: 1px solid var(--border-color);
  padding: 1.25rem 0;
}

.faq-question {
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-answer {
  padding-top: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Sidebar Widgets */
.sidebar-sticky {
  position: sticky;
  top: 5.5rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.widget-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.widget-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-subtle);
}

.author-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.author-avatar {
  width: 4rem;
  height: 4rem;
  border-radius: var(--radius-full);
  background: var(--brand-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.author-name {
  font-weight: 700;
  color: var(--text-primary);
}

.author-title {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

/* Footer */
.site-footer {
  margin-top: auto;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 1rem 0;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

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

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  flex-wrap: wrap;
  gap: 1rem;
}

/* ==========================================================================
   Modern 2026 Core Tracks Showcase
   ========================================================================== */
.tracks-showcase-section {
  margin: 3.5rem 0 4rem;
}

.tracks-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

@media (max-width: 1080px) {
  .tracks-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .tracks-grid {
    grid-template-columns: 1fr;
  }
}

.track-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  text-decoration: none;
  color: inherit;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.track-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--border-color);
  transition: background 0.2s ease;
}

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

.track-card-quant::before { background: #10b981; }
.track-card-quant:hover { border-color: rgba(16, 185, 129, 0.5); box-shadow: 0 10px 25px -5px rgba(16, 185, 129, 0.15); }

.track-card-biz::before { background: #3b82f6; }
.track-card-biz:hover { border-color: rgba(59, 130, 246, 0.5); box-shadow: 0 10px 25px -5px rgba(59, 130, 246, 0.15); }

.track-card-tools::before { background: #f59e0b; }
.track-card-tools:hover { border-color: rgba(245, 158, 11, 0.5); box-shadow: 0 10px 25px -5px rgba(245, 158, 11, 0.15); }

.track-card-vibe::before { background: #a855f7; }
.track-card-vibe:hover { border-color: rgba(168, 85, 247, 0.5); box-shadow: 0 10px 25px -5px rgba(168, 85, 247, 0.15); }

.track-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.track-icon {
  font-size: 1.8rem;
}

.track-tag {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-muted);
}

.track-card h3 {
  font-size: 1.2rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
  line-height: 1.3;
}

.track-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 1.25rem;
  flex: 1;
}

.track-action {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--brand-primary);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

/* ==========================================================================
   Daily Streak / Dev Challenge Gamification Card
   ========================================================================== */
.daily-streak-section {
  margin: 3.5rem 0;
}

.daily-streak-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem 2rem;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.daily-streak-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.daily-title-wrap {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.daily-icon {
  font-size: 2rem;
}

.daily-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-primary);
  margin: 0;
}

.daily-badge {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--brand-hover);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.streak-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.35);
  color: #f59e0b;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
}

.daily-question {
  font-size: 1.05rem;
  color: var(--text-primary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
  font-weight: 500;
}

.daily-options-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.85rem;
  margin-bottom: 1rem;
}

.daily-challenge-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.85rem 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  color: var(--text-primary);
  text-align: left;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
}

.daily-challenge-btn:hover:not(:disabled) {
  background: var(--bg-tertiary);
  border-color: var(--brand-primary);
  transform: translateY(-2px);
}

.daily-challenge-btn:disabled {
  cursor: default;
}

.daily-challenge-btn.correct {
  background: rgba(16, 185, 129, 0.2) !important;
  border-color: #10b981 !important;
  color: #10b981 !important;
  font-weight: 700;
}

.daily-challenge-btn.wrong {
  background: rgba(239, 68, 68, 0.2) !important;
  border-color: #ef4444 !important;
  color: #ef4444 !important;
}

.daily-feedback-box {
  margin-top: 1rem;
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  display: none;
}

/* ==========================================================================
   4-Category AI App Directory Showcase (53 Apps)
   ========================================================================== */
.ai-directory-showcase {
  margin: 4.5rem 0;
}

.section-badge-pill {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #f59e0b;
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.3);
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.6rem;
}

.section-cta-link {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--brand-hover);
  text-decoration: none;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
}

.section-cta-link.link-green {
  color: #10b981;
}

.ai-categories-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

@media (max-width: 1080px) {
  .ai-categories-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .ai-categories-grid {
    grid-template-columns: 1fr;
  }
}

.ai-cat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.ai-cat-card:hover {
  transform: translateY(-3px);
  border-color: var(--brand-primary);
}

.ai-cat-header {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 0.85rem;
}

.ai-cat-icon-wrap {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
}

.cat-color-prod { background: rgba(245, 158, 11, 0.15); border: 1px solid rgba(245, 158, 11, 0.3); }
.cat-color-asst { background: rgba(59, 130, 246, 0.15); border: 1px solid rgba(59, 130, 246, 0.3); }
.cat-color-img  { background: rgba(236, 72, 153, 0.15); border: 1px solid rgba(236, 72, 153, 0.3); }
.cat-color-vid  { background: rgba(16, 185, 129, 0.15); border: 1px solid rgba(16, 185, 129, 0.3); }

.ai-cat-name {
  font-size: 1.15rem;
  font-weight: 800;
  line-height: 1.25;
}

.ai-cat-count {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 600;
}

.ai-cat-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 1.25rem;
}

.ai-cat-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1.5rem;
  flex: 1;
}

.tool-mini-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.65rem;
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  transition: all 0.15s ease;
}

.tool-mini-chip:hover {
  background: var(--bg-tertiary);
  border-color: var(--brand-hover);
  color: var(--brand-hover);
}

.chip-rate {
  font-size: 0.72rem;
  color: #f59e0b;
}

.ai-cat-footer-link {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--brand-primary);
  border-top: 1px solid var(--border-subtle);
  padding-top: 0.85rem;
  text-decoration: none;
}

/* ==========================================================================
   AI Trading Command Center
   ========================================================================== */
.quant-command-center {
  margin: 4.5rem 0;
  background: linear-gradient(145deg, rgba(16, 185, 129, 0.08) 0%, rgba(15, 23, 42, 0.95) 100%);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  position: relative;
  overflow: hidden;
}

.quant-header-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.quant-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.35);
  color: #10b981;
  padding: 0.25rem 0.8rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.quant-title {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 0.5rem;
}

.quant-subtitle {
  color: var(--text-secondary);
  max-width: 720px;
  font-size: 0.98rem;
  line-height: 1.55;
}

.quant-cta-btn {
  background: #10b981;
  color: #0f172a;
  font-weight: 800;
  font-size: 0.92rem;
  padding: 0.75rem 1.4rem;
  border-radius: 8px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: transform 0.15s ease, background 0.15s ease;
  white-space: nowrap;
}

.quant-cta-btn:hover {
  background: #059669;
  color: white;
  transform: translateY(-2px);
}

.quant-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 1.5rem;
}

@media (max-width: 960px) {
  .quant-grid {
    grid-template-columns: 1fr;
  }
}

.quant-flagship-box {
  background: var(--bg-secondary);
  border: 1px solid rgba(16, 185, 129, 0.28);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.flagship-top-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.flagship-tag {
  font-size: 0.75rem;
  font-weight: 800;
  color: #10b981;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.flagship-duration {
  font-size: 0.8rem;
  background: rgba(16, 185, 129, 0.15);
  color: #10b981;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  font-weight: 700;
}

.flagship-course-title {
  font-size: 1.25rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
  line-height: 1.35;
}

.flagship-course-title a {
  color: var(--text-primary);
  text-decoration: none;
}

.flagship-course-title a:hover {
  color: #10b981;
}

.flagship-course-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 1.25rem;
}

.flagship-tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.5rem;
}

.flagship-tech-stack span {
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.05);
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
  font-weight: 600;
}

.flagship-action-btn {
  display: inline-block;
  text-align: center;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.4);
  color: #10b981;
  font-weight: 700;
  padding: 0.75rem 1rem;
  border-radius: 6px;
  text-decoration: none;
  font-size: 0.9rem;
  transition: all 0.15s ease;
}

.flagship-action-btn:hover {
  background: #10b981;
  color: #0f172a;
}

.quant-blueprints-column {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.quant-bp-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-decoration: none;
  color: inherit;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: border-color 0.2s ease, transform 0.15s ease;
}

.quant-bp-item:hover {
  border-color: #10b981;
  transform: translateX(4px);
}

.bp-subtag {
  font-size: 0.72rem;
  font-weight: 700;
  color: #10b981;
  text-transform: uppercase;
  margin-bottom: 0.2rem;
}

.bp-name {
  font-weight: 700;
  font-size: 1.02rem;
  line-height: 1.3;
  margin-bottom: 0.25rem;
}

.bp-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.bp-yield {
  text-align: right;
  min-width: 85px;
}

.yield-val {
  font-size: 0.95rem;
  font-weight: 800;
  color: #10b981;
  display: block;
}

.yield-lbl {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Master Courses & Interactive Filters
   ========================================================================== */
.tutorials-section {
  margin: 4.5rem 0;
}

.tutorial-filters-bar {
  display: flex;
  gap: 0.6rem;
  overflow-x: auto;
  padding: 0.25rem 0 0.75rem;
  margin-bottom: 2rem;
  scrollbar-width: thin;
}

.tutorial-filter-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.15rem;
  border-radius: var(--radius-full);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.88rem;
  font-weight: 600;
  white-space: nowrap;
  cursor: pointer;
  transition: all 0.15s ease;
}

.tutorial-filter-btn:hover {
  color: var(--text-primary);
  border-color: var(--brand-primary);
}

.tutorial-filter-btn.active {
  background: var(--brand-primary);
  color: white;
  border-color: var(--brand-primary);
  box-shadow: 0 0 12px var(--brand-glow);
}

.meta-difficulty {
  color: var(--brand-hover);
  font-weight: 700;
}

/* ==========================================================================
   AI Business Blueprints Grid
   ========================================================================== */
.biz-blueprints-section {
  margin: 4.5rem 0;
}

.title-with-icon {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.title-icon {
  font-size: 1.75rem;
}

.biz-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

@media (max-width: 1080px) {
  .biz-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .biz-grid {
    grid-template-columns: 1fr;
  }
}

.biz-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.biz-card:hover {
  transform: translateY(-3px);
  border-color: #3b82f6;
}

.biz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.6rem;
}

.biz-cat {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: #3b82f6;
}

.biz-mrr {
  font-size: 0.85rem;
  font-weight: 800;
  color: #10b981;
  background: rgba(16, 185, 129, 0.1);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
}

.biz-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
  line-height: 1.35;
}

.biz-title a {
  color: var(--text-primary);
  text-decoration: none;
}

.biz-title a:hover {
  color: #3b82f6;
}

.biz-tagline {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 1.25rem;
}

.biz-footer {
  border-top: 1px solid var(--border-subtle);
  padding-top: 0.85rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.biz-pricing {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.biz-link {
  font-weight: 700;
  font-size: 0.85rem;
  color: #10b981;
  text-decoration: none;
}

/* ==========================================================================
   News Grid & Cards
   ========================================================================== */
.news-section {
  margin-bottom: 4rem;
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

@media (max-width: 900px) {
  .news-grid {
    grid-template-columns: 1fr;
  }
}

.news-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color 0.15s ease;
}

.news-card:hover {
  border-color: var(--brand-primary);
}

.news-meta {
  font-size: 0.75rem;
  color: var(--brand-primary);
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 0.4rem;
  display: flex;
  gap: 0.4rem;
}

.news-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  line-height: 1.4;
}

.news-title a {
  color: var(--text-primary);
  text-decoration: none;
}

.news-title a:hover {
  color: var(--brand-hover);
}

.news-excerpt {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 1rem;
}

.news-link {
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--brand-primary);
  text-decoration: none;
}

/* ==========================================================================
   Cheatsheets Grid
   ========================================================================== */
.cheatsheets-section {
  margin: 4rem 0;
}

.cheatsheets-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

@media (max-width: 1080px) {
  .cheatsheets-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .cheatsheets-grid {
    grid-template-columns: 1fr;
  }
}

.cheatsheet-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.cheatsheet-card:hover {
  transform: translateY(-3px);
  border-color: var(--brand-primary);
}

.cs-category {
  font-size: 0.78rem;
  color: var(--brand-primary);
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.cs-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  line-height: 1.35;
}

.cs-title a {
  color: var(--text-primary);
  text-decoration: none;
}

.cs-summary {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  line-height: 1.5;
}

.cs-link {
  font-weight: 700;
  font-size: 0.88rem;
  color: var(--brand-primary);
  text-decoration: none;
}

/* ==========================================================================
   Lead Magnet Section
   ========================================================================== */
.lead-magnet-section {
  margin: 4.5rem 0;
}

.lead-magnet-card {
  background: linear-gradient(135deg, rgba(139, 92, 246, 0.15) 0%, rgba(59, 130, 246, 0.15) 100%);
  border: 1px solid rgba(139, 92, 246, 0.35);
  border-radius: var(--radius-lg);
  padding: 3rem 1.5rem;
  text-align: center;
}

.magnet-icon {
  font-size: 2.5rem;
}

.magnet-title {
  font-size: clamp(1.4rem, 3vw, 1.85rem);
  font-weight: 800;
  margin: 0.75rem 0;
}

.magnet-desc {
  max-width: 650px;
  margin: 0 auto 1.75rem;
  color: var(--text-secondary);
  font-size: 1.02rem;
  line-height: 1.6;
}

.highlight-code {
  color: var(--brand-hover);
  background: rgba(59, 130, 246, 0.1);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
}

.newsletter-form {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  max-width: 520px;
  margin: 0 auto;
}

.magnet-input {
  flex: 1;
  min-width: 240px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  color: var(--text-primary);
  outline: none;
}

.magnet-submit-btn {
  background: var(--brand-primary);
  color: white;
  border: none;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  cursor: pointer;
  font-size: 1rem;
  transition: background 0.15s ease;
}

.magnet-submit-btn:hover {
  background: var(--brand-hover);
}

/* ==========================================================================
   Slide-Over Mobile Navigation Drawer (2026 UX)
   ========================================================================== */
@media (min-width: 769px) {
  .mobile-nav-drawer,
  .mobile-nav-backdrop,
  .mobile-menu-btn {
    display: none !important;
  }
}

.mobile-nav-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 998;
  opacity: 0;
  pointer-events: none;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.mobile-nav-backdrop.active {
  opacity: 1;
  pointer-events: auto;
  visibility: visible;
}

.mobile-nav-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: min(320px, 85vw);
  height: 100vh;
  background: var(--bg-secondary);
  border-left: 1px solid var(--border-color);
  z-index: 999;
  transform: translateX(100%);
  visibility: hidden;
  pointer-events: none;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.3s ease;
  display: flex;
  flex-direction: column;
  box-shadow: -10px 0 30px rgba(0, 0, 0, 0.5);
  overflow-y: auto;
}

.mobile-nav-drawer.active {
  transform: translateX(0);
  visibility: visible;
  pointer-events: auto;
}

.mobile-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-subtle);
}

.mobile-drawer-close {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.mobile-drawer-close:hover {
  background: var(--border-color);
}

.mobile-drawer-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  flex: 1;
}

.mobile-lang-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  text-decoration: none;
  font-size: 0.9rem;
}

.mobile-drawer-nav {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.mobile-nav-section-title {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.5rem;
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.92rem;
  min-height: 44px; /* Touch target minimum */
  transition: all 0.15s ease;
}

.mobile-nav-link:hover, .mobile-nav-link.active {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.mobile-nav-link.active {
  border-left: 3px solid var(--brand-primary);
  color: var(--brand-hover);
}

.mobile-drawer-footer {
  margin-top: auto;
  padding-top: 1rem;
}

.mobile-drawer-cta {
  display: block;
  text-align: center;
  background: var(--brand-primary);
  color: white;
  font-weight: 700;
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-size: 0.92rem;
  min-height: 44px;
  line-height: 20px;
}

/* Responsive Ad Adjustments */
@media (max-width: 768px) {
  .ad-slot-wrap {
    margin: 1.5rem 0;
  }
  .ad-leaderboard, .ad-in-content {
    min-height: 95px;
    max-width: 100%;
  }
  .ad-fallback-card {
    flex-direction: column;
    text-align: center;
    padding: 1rem 0.75rem;
    gap: 0.65rem;
  }
  .ad-card-sub {
    white-space: normal;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }
}

/* ==========================================================================
   Comprehensive Responsive Breakpoints (Mobile & PC)
   ========================================================================== */
@media (max-width: 1024px) {
  .hero {
    padding: 4rem 0 3rem;
  }
  .quant-command-center {
    padding: 2rem;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
}

@media (max-width: 768px) {
  .site-header .nav-links {
    display: none;
  }
  .mobile-menu-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 44px;
    min-height: 44px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1.25rem;
    cursor: pointer;
  }
  .hero h1 {
    font-size: clamp(1.8rem, 6vw, 2.5rem);
  }
  .hero-stats {
    gap: 1.75rem;
  }
  .quant-header-row {
    flex-direction: column;
    align-items: flex-start;
  }
  .quant-cta-btn {
    width: 100%;
    justify-content: center;
  }
  .quant-bp-item {
    flex-direction: column;
    align-items: flex-start;
  }
  .bp-yield {
    text-align: left;
    margin-top: 0.5rem;
  }
  .lead-magnet-card {
    padding: 2rem 1.25rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }
  .nav-wrap {
    gap: 0.5rem;
  }
  .lang-switch-btn .lang-switch-hint {
    display: none;
  }
  .lang-switch-btn {
    padding: 0.35rem 0.55rem;
    font-size: 0.8rem;
  }
  .hero {
    padding: 3rem 0 2rem;
  }
  .hero-quick-chips {
    gap: 0.5rem;
  }
  .quick-chip {
    font-size: 0.8rem;
    padding: 0.4rem 0.75rem;
  }
  .hero-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
  }
  .search-kbd-hint {
    display: none;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
}