/* ===================================================================
 * HEROX ROHIT (heroxrohit.in) - Master Stylesheet
 * High-performance, Accessible, Mobile-first, Dark/Light Mode
 * CSS 3D Transforms, Glassmorphism, Zero Layout Shift
 * =================================================================== */

:root {
  /* Color Palette - Dark Theme (Default) */
  --bg-base: #080a0f;
  --bg-surface: #0f1422;
  --bg-surface-elevated: #161d31;
  --bg-card: rgba(22, 29, 49, 0.7);
  --bg-glass: rgba(15, 20, 34, 0.75);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(99, 102, 241, 0.4);

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-faint: #64748b;
  --text-inverse: #0a0c14;

  /* Accent Colors */
  --primary: #6366f1;
  --primary-light: #818cf8;
  --primary-dark: #4f46e5;
  --secondary: #a855f7;
  --accent-pink: #ec4899;
  --accent-cyan: #06b6d4;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
  --gradient-subtle: linear-gradient(135deg, rgba(99, 102, 241, 0.15) 0%, rgba(168, 85, 247, 0.15) 100%);
  --gradient-card: linear-gradient(180deg, rgba(30, 41, 59, 0.6) 0%, rgba(15, 23, 42, 0.8) 100%);
  --glow-primary: 0 0 25px rgba(99, 102, 241, 0.35);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.25);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-display: 'Plus Jakarta Sans', var(--font-sans);

  /* Spacing & Layout */
  --container-max: 1220px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --header-height: 72px;

  /* Transition Speeds */
  --trans-fast: 0.18s cubic-bezier(0.4, 0, 0.2, 1);
  --trans-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --trans-smooth: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Light Theme Overrides */
[data-theme="light"] {
  --bg-base: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #f1f5f9;
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-glass: rgba(255, 255, 255, 0.85);
  --border-color: rgba(0, 0, 0, 0.08);
  --border-hover: rgba(99, 102, 241, 0.5);

  --text-main: #0f172a;
  --text-muted: #475569;
  --text-faint: #64748b;
  --text-inverse: #f8fafc;

  --gradient-card: linear-gradient(180deg, rgba(255, 255, 255, 0.9) 0%, rgba(241, 245, 249, 0.9) 100%);
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 16px 40px rgba(15, 23, 42, 0.12);
  --shadow-glow: 0 0 25px rgba(99, 102, 241, 0.18);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.001s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001s !important;
  }
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-main);
  line-height: 1.65;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--trans-base), color var(--trans-base);
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--trans-fast);
}

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

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

/* Accessibility Focus Outline */
:focus-visible {
  outline: 2px solid var(--primary-light);
  outline-offset: 3px;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

.container-narrow {
  max-width: 860px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* Typography Helpers */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.25;
  color: var(--text-main);
}

h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); }
h2 { font-size: clamp(1.75rem, 3.5vw, 2.4rem); }
h3 { font-size: clamp(1.3rem, 2.5vw, 1.7rem); }
h4 { font-size: 1.2rem; }

.gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }

/* ===================================================================
 * HEADER & NAVIGATION
 * =================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--header-height);
  background: var(--bg-glass);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  transition: background var(--trans-base), box-shadow var(--trans-base);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  transition: transform var(--trans-fast);
}

.brand-logo:hover {
  transform: translateY(-1px);
}

.brand-logo img {
  height: 38px;
  width: auto;
  display: block;
  transition: filter var(--trans-fast), transform var(--trans-fast);
}

.brand-logo:hover img {
  filter: drop-shadow(0 4px 14px rgba(99, 102, 241, 0.5));
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-item {
  position: relative;
}

.nav-link {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-muted);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  transition: color var(--trans-fast), background var(--trans-fast);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-main);
}

/* Dropdown Menu */
.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  width: 280px;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: 10px;
  list-style: none;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--trans-fast);
  z-index: 1010;
}

.nav-item:hover .dropdown-menu,
.nav-item:focus-within .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(4px);
}

.dropdown-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--trans-fast);
}

.dropdown-link:hover {
  background: var(--gradient-subtle);
  color: var(--text-main);
  transform: translateX(4px);
}

.dropdown-link svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* Nav Actions (Theme Toggle & Mobile Burger) */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.theme-toggle-btn {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  width: 42px;
  height: 42px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--trans-fast);
}

.theme-toggle-btn:hover {
  color: var(--primary-light);
  border-color: var(--primary);
  transform: scale(1.05);
}

.theme-toggle-btn svg {
  width: 20px;
  height: 20px;
}

.mobile-menu-btn {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-main);
  cursor: pointer;
  padding: 8px;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition: background var(--trans-fast), color var(--trans-fast);
  z-index: 1001;
}

.mobile-menu-btn:hover, .mobile-menu-btn:focus-visible {
  color: var(--primary-light);
  background: var(--bg-surface-elevated);
}

.mobile-menu-btn svg {
  width: 28px;
  height: 28px;
  display: block;
}

/* Mobile Drawer Backdrop Overlay */
.mobile-nav-backdrop {
  display: none;
}

/* Mobile Drawer */
.mobile-nav-drawer {
  display: none;
}

@media (max-width: 960px) {
  .nav-links {
    display: none;
  }
  
  .mobile-menu-btn {
    display: inline-flex;
  }

  .mobile-nav-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.65);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    z-index: 998;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity var(--trans-base), visibility var(--trans-base);
  }

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

  .mobile-nav-drawer {
    display: block;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
    padding: 24px 28px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.45);
    transform: translateY(-110%);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.25s ease, visibility 0.3s ease;
    z-index: 999;
    max-height: calc(100vh - var(--header-height) - 20px);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .mobile-nav-drawer.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .mobile-nav-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
  }

  .mobile-nav-links > li > a {
    font-size: 1.15rem;
    font-weight: 700;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: var(--text-main);
    transition: background var(--trans-fast), color var(--trans-fast);
  }

  .mobile-nav-links > li > a:hover {
    background: var(--gradient-subtle);
    color: var(--primary-light);
  }

  .mobile-nav-links > li > strong {
    display: block;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-faint);
    padding: 8px 14px 4px;
    margin-top: 6px;
  }

  .mobile-sublinks {
    padding-left: 8px;
    margin-top: 4px;
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 6px;
  }

  .mobile-sublinks a {
    font-size: 0.98rem;
    font-weight: 500;
    color: var(--text-muted);
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all var(--trans-fast);
  }

  .mobile-sublinks a:hover {
    color: var(--primary-light);
    background: var(--bg-surface-elevated);
    transform: translateX(4px);
  }
}

/* ===================================================================
 * BUTTONS & INTERACTIVE ELEMENTS
 * =================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95rem;
  padding: 12px 26px;
  border-radius: var(--radius-md);
  cursor: pointer;
  border: none;
  transition: all var(--trans-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-primary);
  color: #ffffff;
  box-shadow: 0 4px 18px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
  box-shadow: 0 6px 26px rgba(99, 102, 241, 0.55);
  transform: translateY(-2px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-main);
}

.btn-secondary:hover {
  border-color: var(--primary);
  background: var(--gradient-subtle);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--primary-light);
  color: var(--primary-light);
}

.btn-outline:hover {
  background: var(--primary);
  color: #ffffff;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.85rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

/* Badge Pill */
.badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--gradient-subtle);
  border: 1px solid var(--border-hover);
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--primary-light);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ===================================================================
 * HERO SECTION WITH 3D CANVAS
 * =================================================================== */
.hero-section {
  position: relative;
  padding: 80px 0 100px;
  overflow: hidden;
  background: radial-gradient(circle at 50% 20%, rgba(99, 102, 241, 0.12) 0%, transparent 60%);
}

#hero-3d-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
  opacity: 0.9;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 860px;
  margin: 0 auto;
}

.hero-title {
  margin: 20px 0 16px;
  letter-spacing: -0.03em;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 36px;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 50px;
}

/* Hero Stats Row */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 40px;
}

.stat-card {
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform var(--trans-fast), border-color var(--trans-fast);
}

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

.stat-number {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.1;
}

.stat-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-top: 6px;
}

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

/* ===================================================================
 * 3D CARDS & TOOL PREVIEWS
 * =================================================================== */
.section {
  padding: 90px 0;
  position: relative;
}

.section-alt {
  background-color: var(--bg-surface);
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 60px;
}

.section-title {
  margin-top: 12px;
  margin-bottom: 14px;
}

.section-desc {
  font-size: 1.1rem;
  color: var(--text-muted);
}

/* 3D Flip Card Component */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

.flip-card {
  background-color: transparent;
  height: 380px;
  perspective: 1200px;
}

.flip-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: left;
  transition: transform 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  transform-style: preserve-3d;
  cursor: pointer;
}

.flip-card:hover .flip-card-inner,
.flip-card:focus-within .flip-card-inner {
  transform: rotateY(180deg);
}

.flip-card-front, .flip-card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
}

.flip-card-front {
  background: var(--gradient-card);
}

.flip-card-front:hover {
  border-color: var(--border-hover);
}

.flip-card-back {
  background: var(--bg-surface-elevated);
  transform: rotateY(180deg);
  border-color: var(--primary-light);
}

.card-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-badge {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--gradient-subtle);
  color: var(--primary-light);
  align-self: flex-start;
  margin-bottom: 14px;
}

.card-title {
  font-size: 1.35rem;
  margin-bottom: 10px;
}

.card-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.55;
}

.card-footer-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary-light);
}

/* ===================================================================
 * GENERATOR ENGINE & TOOL INTERFACE
 * =================================================================== */
.tool-hero {
  padding: 50px 0 40px;
  background: radial-gradient(circle at 50% 0%, rgba(99, 102, 241, 0.15) 0%, transparent 60%);
}

.generator-box {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px 32px;
  box-shadow: var(--shadow-lg);
  margin-top: 30px;
  margin-bottom: 50px;
  position: relative;
  overflow: hidden;
}

.generator-box::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-primary);
}

.generator-form {
  display: grid;
  grid-template-columns: 2fr 1.2fr 1fr auto;
  gap: 16px;
  align-items: flex-end;
}

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

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-label {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 6px;
}

.form-control {
  width: 100%;
  padding: 14px 18px;
  background: var(--bg-surface);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--trans-fast), box-shadow var(--trans-fast);
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

/* Generator Action Bar */
.generator-controls-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--border-color);
}

.controls-left, .controls-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

/* Results Grid */
.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 32px;
  margin-bottom: 20px;
}

.results-count {
  font-weight: 700;
  font-size: 1.1rem;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
  margin-bottom: 30px;
}

.result-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 14px;
  transition: all var(--trans-fast);
  position: relative;
}

.result-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.result-name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
  word-break: break-word;
  color: var(--text-main);
}

.result-tag {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-faint);
  text-transform: uppercase;
}

.result-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  border-top: 1px solid var(--border-color);
  padding-top: 12px;
}

.btn-icon-action {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--trans-fast);
}

.btn-icon-action:hover {
  color: var(--text-main);
  border-color: var(--primary);
  background: var(--gradient-subtle);
}

.btn-icon-action.favorited {
  color: var(--accent-pink);
  border-color: var(--accent-pink);
  background: rgba(236, 72, 153, 0.15);
}

.btn-check-avail {
  margin-left: auto;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 6px 12px;
  background: var(--gradient-subtle);
  border: 1px solid var(--border-hover);
  border-radius: var(--radius-sm);
  color: var(--primary-light);
  cursor: pointer;
  transition: all var(--trans-fast);
}

.btn-check-avail:hover {
  background: var(--primary);
  color: #ffffff;
}

/* ===================================================================
 * MODALS & DRAWERS (Availability Checker & Favorites)
 * =================================================================== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--trans-fast), visibility var(--trans-fast);
}

.modal-overlay.open {
  opacity: 1;
  visibility: visible;
}

.modal-dialog {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  max-width: 520px;
  width: 100%;
  padding: 30px;
  box-shadow: var(--shadow-lg);
  position: relative;
  transform: scale(0.95);
  transition: transform var(--trans-fast);
}

.modal-overlay.open .modal-dialog {
  transform: scale(1);
}

.modal-close-btn {
  position: absolute;
  top: 18px;
  right: 18px;
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 1.5rem;
  line-height: 1;
}

.modal-title {
  margin-bottom: 8px;
}

.avail-links-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 24px;
}

.avail-link-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--trans-fast);
}

.avail-link-card:hover {
  border-color: var(--primary);
  transform: translateX(4px);
  background: var(--gradient-subtle);
}

/* ===================================================================
 * SEO CONTENT & ARTICLE STYLING
 * =================================================================== */
.article-container {
  padding: 60px 0;
}

.article-header {
  margin-bottom: 40px;
  text-align: center;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-top: 16px;
  color: var(--text-muted);
  font-size: 0.9rem;
  flex-wrap: wrap;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-main);
}

.article-body p {
  margin-bottom: 24px;
}

.article-body h2 {
  margin-top: 50px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border-color);
  position: relative;
}

.article-body h2::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--gradient-primary);
}

.article-body h3 {
  margin-top: 36px;
  margin-bottom: 16px;
}

.article-body ul, .article-body ol {
  margin-bottom: 26px;
  padding-left: 28px;
}

.article-body li {
  margin-bottom: 10px;
}

/* Table of Contents */
.toc-box {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  margin: 36px 0;
}

.toc-title {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toc-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toc-link {
  color: var(--text-muted);
  font-weight: 500;
  transition: color var(--trans-fast);
}

.toc-link:hover {
  color: var(--primary-light);
  text-decoration: underline;
}

/* Article Images & Diagrams */
.article-featured-image {
  margin: 28px 0 36px 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  background: var(--bg-surface-elevated);
}

.article-featured-image img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

.article-figure {
  margin: 40px auto;
  text-align: center;
  max-width: 820px;
}

.article-figure img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  background: var(--bg-surface-elevated);
}

.article-figure figcaption {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-top: 12px;
  font-style: italic;
  line-height: 1.4;
}

.blog-card {
  cursor: pointer;
  transition: transform var(--trans-base), border-color var(--trans-base), box-shadow var(--trans-base);
}

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

.blog-card:hover h2 a {
  color: var(--primary-light) !important;
}

/* Blog Card Thumbnail Previews */
.blog-card-thumb {
  width: 100%;
  height: 180px;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 18px;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  display: block;
}

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

.blog-card:hover .blog-card-thumb img {
  transform: scale(1.04);
}

/* Callout Box */
.callout {
  background: var(--bg-surface-elevated);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  margin: 30px 0;
  border-left: 4px solid var(--primary);
}

.callout-title {
  font-weight: 800;
  font-size: 1rem;
  margin-bottom: 6px;
  color: var(--primary-light);
}

/* FAQ Accordion */
.faq-section {
  margin-top: 50px;
}

.faq-item {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 14px;
  overflow: hidden;
  transition: border-color var(--trans-fast);
}

.faq-item:hover {
  border-color: var(--border-hover);
}

.faq-question {
  padding: 20px 24px;
  font-weight: 700;
  font-size: 1.05rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  list-style: none;
  user-select: none;
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-question svg {
  width: 20px;
  height: 20px;
  transition: transform var(--trans-fast);
  color: var(--primary-light);
}

details[open] .faq-question svg {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 24px 22px;
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.7;
}

/* Author Box */
.author-box {
  display: flex;
  align-items: center;
  gap: 24px;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
  margin-top: 60px;
}

.author-avatar {
  width: 90px;
  height: 90px;
  border-radius: 50%;
  flex-shrink: 0;
  border: 2px solid var(--primary-light);
}

.author-info h4 {
  font-size: 1.25rem;
  margin-bottom: 6px;
}

.author-role {
  font-size: 0.85rem;
  color: var(--primary-light);
  font-weight: 700;
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.author-bio {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.6;
}

@media (max-width: 600px) {
  .author-box {
    flex-direction: column;
    text-align: center;
  }
}

/* ===================================================================
 * ADSENSE PLACEHOLDERS (CLS-SAFE)
 * =================================================================== */
.ad-slot-container {
  margin: 36px auto;
  text-align: center;
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* Reserved heights prevent Cumulative Layout Shift */
.ad-slot-header {
  min-height: 90px;
  max-width: 728px;
  width: 100%;
}

.ad-slot-in-article {
  min-height: 250px;
  max-width: 750px;
  width: 100%;
}

.ad-slot-sidebar {
  min-height: 600px;
  max-width: 300px;
  width: 100%;
}

.ad-slot-footer {
  min-height: 90px;
  max-width: 970px;
  width: 100%;
}

.ad-slot-placeholder {
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-sm);
  width: 100%;
  height: 100%;
  min-height: inherit;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-faint);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* ===================================================================
 * GDPR COOKIE CONSENT BANNER
 * =================================================================== */
.cookie-banner {
  position: fixed;
  bottom: 24px;
  left: 24px;
  right: 24px;
  max-width: 580px;
  margin-left: auto;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-hover);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-lg);
  z-index: 3000;
  display: none;
  animation: slideUp 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes slideUp {
  from { transform: translateY(100px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

.cookie-content h4 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.cookie-content p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 16px;
}

.cookie-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* ===================================================================
 * FOOTER
 * =================================================================== */
.site-footer {
  margin-top: auto;
  background: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  padding: 70px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 50px;
}

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

@media (max-width: 540px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

.footer-col h4 {
  font-size: 1.05rem;
  margin-bottom: 20px;
  color: var(--text-main);
  position: relative;
  display: inline-block;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 0.92rem;
  transition: color var(--trans-fast), transform var(--trans-fast);
  display: inline-block;
}

.footer-links a:hover {
  color: var(--primary-light);
  transform: translateX(3px);
}

.footer-brand-p {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.6;
  margin-top: 14px;
  margin-bottom: 20px;
  max-width: 320px;
}

.footer-contact-item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-bottom: 10px;
}

.footer-contact-item a {
  color: var(--primary-light);
  font-weight: 600;
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--text-faint);
  font-size: 0.88rem;
}

/* Toast Notifications */
.toast-box {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--primary);
  color: var(--text-main);
  padding: 14px 22px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-weight: 600;
  font-size: 0.92rem;
  z-index: 4000;
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: all var(--trans-fast);
}

.toast-box.show {
  opacity: 1;
  transform: translateY(0);
}

/* Scroll Reveal Utility */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* Breadcrumbs */
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-faint);
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.breadcrumbs a {
  color: var(--text-muted);
}

.breadcrumbs a:hover {
  color: var(--primary-light);
}

.breadcrumbs span.current {
  color: var(--text-main);
  font-weight: 600;
}