/* GridEdge AI - Dark Industrial Theme
   ====================================
   All colors defined here for easy customization.
   Change the CSS variables below to adjust the entire site's palette.
*/

:root {
  /* Background colors - medium-dark industrial slate (not cave-dark) */
  --bg-primary: #1e3040;
  --bg-secondary: #252d3a;
  --bg-tertiary: #2e3847;
  --bg-card: #2a3342;

  /* Text colors */
  --text-primary: #f0f2f5;
  --text-secondary: #b0b8c4;
  --text-muted: #6b7787;

  /* Primary accent - brand orange */
  --accent: #ff914d;
  --accent-hover: #ffab75;
  --accent-dark: #e07a3a;
  --accent-subtle: rgba(255, 145, 77, 0.15);
  --accent-glow: rgba(255, 145, 77, 0.25);

  /* Secondary accent - brand cyan */
  --accent-secondary: #b5e7f0;
  --accent-secondary-hover: #d0f0f7;
  --accent-secondary-subtle: rgba(181, 231, 240, 0.15);

  /* Tertiary accent - brand gold */
  --accent-tertiary: #fcbc5b;
  --accent-tertiary-hover: #fdd080;

  /* Borders and dividers */
  --border: #3d4a5c;
  --border-subtle: #333d4d;
  --border-light: #4a576a;

  /* Status colors */
  --success: #34d399;
  --warning: #fbbf24;
  --error: #f87171;

  /* Typography - Comfortaa site-wide (rounded, modern) */
  --font-heading: 'Comfortaa', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Comfortaa', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing scale - reduced ~30-40% from original */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 0.875rem;
  --space-lg: 1.25rem;
  --space-xl: 1.5rem;
  --space-2xl: 2rem;
  --space-3xl: 2.5rem;
  --space-4xl: 3.5rem;

  /* Container widths */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1200px;

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

  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  /* Shadows - anti-flat depth */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3), 0 2px 4px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.35), 0 4px 8px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 15px 30px rgba(0, 0, 0, 0.4), 0 6px 12px rgba(0, 0, 0, 0.25);
  --shadow-inset: inset 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-glow: 0 0 20px var(--accent-glow);

  /* Gradients - anti-flat depth */
  --gradient-card: linear-gradient(145deg, var(--bg-card) 0%, #242c38 100%);
  --gradient-btn-primary: linear-gradient(180deg, #ffa366 0%, var(--accent) 50%, var(--accent-dark) 100%);
  --gradient-btn-primary-hover: linear-gradient(180deg, #ffb880 0%, var(--accent-hover) 50%, var(--accent) 100%);
  --gradient-section: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  --gradient-hero-overlay: linear-gradient(180deg, rgba(20, 28, 38, 0.6) 0%, rgba(20, 28, 38, 0.85) 100%);
}

/* Reset and base styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.25;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
}

h1 { font-size: 2.5rem; font-weight: 700; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
}

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

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

strong { font-weight: 600; }
em { font-style: italic; }

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

.container-narrow {
  max-width: var(--container-xl);
}

/* Header / Navigation */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(11, 44, 70, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 2px solid rgba(181, 231, 240, 0.5);
  padding: var(--space-md) 0;
  box-shadow: var(--shadow-md);
}

.site-header .container {
  max-width: none;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.logo img {
  height: 40px;
  width: auto;
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

/* Navigation */
.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: var(--space-lg);
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 1.1875rem;
  font-weight: 700;
  padding: var(--space-sm) 0;
  position: relative;
  transition: color var(--transition-fast);
}

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

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition-base);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--space-sm);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn-primary {
  background: rgba(11, 44, 70, 0.95);
  color: var(--accent-secondary);
  border: 2px solid rgba(181, 231, 240, 0.5);
}

.btn-primary:hover {
  background: rgba(11, 44, 70, 1);
  color: var(--accent-secondary-hover);
  border-color: var(--accent);
  transform: translateY(-2px);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-large {
  padding: var(--space-md) var(--space-xl);
  font-size: 1.1875rem;
}

/* Hero buttons - matches nav bar (navy blue bg, cyan border) */
.btn-hero {
  background: rgba(11, 44, 70, 0.95);
  color: var(--accent-secondary);
  border: 2px solid rgba(181, 231, 240, 0.5);
  box-shadow: var(--shadow-sm);
}

.btn-hero:hover {
  background: rgba(11, 44, 70, 1);
  color: var(--accent-secondary-hover);
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

/* Hero Section */
.hero {
  padding: calc(var(--space-4xl) + 80px) 0 var(--space-4xl);
  position: relative;
  overflow: hidden;
  background-image: url('/images/home-hero-bg.webp');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  min-height: 110vh;
  display: flex;
  align-items: center;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    180deg,
    rgba(20, 28, 38, 0.15) 0%,
    rgba(20, 28, 38, 0.25) 50%,
    rgba(30, 37, 48, 0.40) 100%
  );
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.hero-logo {
  max-width: 600px;
  width: 100%;
  height: auto;
  margin-bottom: var(--space-3xl);
}

.hero-subtitle {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-4xl);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

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

/* Legacy hero styles (kept for other pages if needed) */
.hero-tagline {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-md);
  padding: var(--space-xs) var(--space-md);
  background: var(--accent-subtle);
  border-radius: var(--radius-sm);
}

.hero h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: var(--space-lg);
}

.hero-description {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
}

/* Section styling */
.section {
  padding: var(--space-4xl) 0;
  border-top: 2px solid rgba(181, 231, 240, 0.5);
  border-bottom: 2px solid rgba(181, 231, 240, 0.5);
}

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

.section-dark {
  background: var(--bg-secondary);
}

/* Sectors section with factory background */
.section-sectors {
  background-image: url('/images/home-sectors-bg.webp');
  background-size: cover;
  background-position: center top;
  background-repeat: no-repeat;
  position: relative;
  padding: 14rem 0 8rem;
  min-height: 110vh;
}

.section-sectors::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    180deg,
    rgba(20, 60, 100, 0.4) 0%,
    rgba(20, 60, 100, 0.35) 50%,
    rgba(20, 60, 100, 0.45) 100%
  );
  pointer-events: none;
}

.section-sectors > .container {
  position: relative;
  z-index: 1;
  max-width: 1400px;
}

.section-header {
  text-align: center;
  margin: 0 auto var(--space-3xl);
}

.section-header h2 {
  margin-bottom: var(--space-md);
}

.section-header p {
  font-size: 1.125rem;
}

/* Cards - Option C: Subtle orange-tinted borders (muted glow) */
.card {
  background: var(--bg-card);
  border: 2px solid rgba(255, 145, 77, 0.3);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

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

.card-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-subtle);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-lg);
  color: var(--accent);
  font-size: 1.5rem;
}

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

.card p {
  font-size: 0.9375rem;
  margin-bottom: 0;
}

/* Grid layouts */
.grid {
  display: grid;
  gap: var(--space-xl);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Products section */
.product-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
  padding: var(--space-3xl) 0;
  border-bottom: 1px solid var(--border-subtle);
}

.product-card:last-child {
  border-bottom: none;
}

.product-card.reverse {
  direction: rtl;
}

.product-card.reverse > * {
  direction: ltr;
}

.product-image {
  aspect-ratio: 16/10;
  background: var(--bg-tertiary);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 2px solid rgba(255, 145, 77, 0.3);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.product-image:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.product-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.product-content h3 {
  font-size: 1.75rem;
  margin-bottom: var(--space-md);
}

.product-features {
  list-style: none;
  margin-top: var(--space-lg);
}

.product-features li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
  color: var(--text-secondary);
}

.product-features li::before {
  content: '•';
  color: var(--accent);
  font-weight: bold;
}

/* Team grid */
.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-xl);
}

.team-card {
  text-align: center;
}

.team-photo {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  margin: 0 auto var(--space-lg);
  overflow: hidden;
  background: var(--bg-tertiary);
  border: 3px solid var(--border);
}

.team-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.team-card h3 {
  margin-bottom: var(--space-xs);
  font-size: 1.25rem;
}

.team-role {
  color: var(--accent);
  font-size: 0.9375rem;
  font-weight: 500;
  margin-bottom: var(--space-md);
}

.team-bio {
  font-size: 0.9375rem;
}

/* Blog / Posts */
.post-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.post-card {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: var(--space-xl);
  padding: var(--space-lg);
  background: var(--bg-card);
  border: 2px solid rgba(255, 145, 77, 0.3);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.post-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.post-image {
  aspect-ratio: 16/10;
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.post-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.post-meta {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
}

.post-card h3 {
  font-size: 1.25rem;
  margin-bottom: var(--space-sm);
}

.post-card h3 a {
  color: var(--text-primary);
}

.post-card h3 a:hover {
  color: var(--accent);
}

.post-excerpt {
  font-size: 0.9375rem;
  margin-bottom: 0;
}

/* Single post */
.post-single {
  max-width: 800px;
  margin: 0 auto;
  padding-top: calc(80px + var(--space-3xl));
}

.post-header {
  margin-bottom: var(--space-3xl);
}

.post-header h1 {
  font-size: 2.5rem;
  margin-bottom: var(--space-md);
}

.post-content {
  font-size: 1.0625rem;
  line-height: 1.75;
}

.post-content h2 {
  margin-top: var(--space-3xl);
}

.post-content h3 {
  margin-top: var(--space-2xl);
}

.post-content ul, .post-content ol {
  margin-bottom: var(--space-lg);
  padding-left: var(--space-xl);
}

.post-content li {
  margin-bottom: var(--space-sm);
  color: var(--text-secondary);
}

.post-content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-tertiary);
  padding: 0.2em 0.4em;
  border-radius: var(--radius-sm);
}

.post-content pre {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  overflow-x: auto;
  margin-bottom: var(--space-lg);
}

.post-content pre code {
  background: none;
  padding: 0;
}

.post-content blockquote {
  border-left: 3px solid var(--accent);
  padding-left: var(--space-lg);
  margin: var(--space-xl) 0;
  font-style: italic;
  color: var(--text-secondary);
}

/* Contact form */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: var(--space-3xl);
}

.contact-info h2 {
  margin-bottom: var(--space-lg);
}

.contact-details {
  margin-top: var(--space-xl);
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.contact-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-subtle);
  border-radius: var(--radius-md);
  color: var(--accent);
  flex-shrink: 0;
}

.contact-item p {
  margin: 0;
}

.contact-item strong {
  display: block;
  color: var(--text-primary);
  margin-bottom: var(--space-xs);
}

/* Form styles */
.form {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.form-group label {
  font-weight: 500;
  color: var(--text-primary);
  font-size: 0.9375rem;
}

.form-group input,
.form-group textarea {
  font-family: var(--font-body);
  font-size: 1rem;
  padding: var(--space-md);
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.form-group textarea {
  resize: vertical;
  min-height: 150px;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--text-secondary);
}

/* Footer - Simple single-line */
.site-footer {
  margin-top: auto;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  padding: var(--space-lg) 0;
}

.footer-simple {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  font-size: 0.875rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  text-transform: uppercase;
}

.footer-simple p {
  margin: 0;
  color: var(--text-primary);
}

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

.footer-simple a:hover {
  color: var(--accent);
}

.footer-sep {
  color: var(--text-primary);
}

.footer-location {
  color: var(--text-primary);
}

/* Page headers */
.page-header {
  padding: calc(80px + var(--space-sm)) 0 var(--space-sm);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-subtle);
}

.page-header h1 {
  margin-bottom: 0;
}

.page-header p {
  font-size: 1.125rem;
}

/* Sectors / Use cases */
.sector-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3xl);
}

.sector-card {
  position: relative;
  aspect-ratio: 4/3;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-tertiary);
  border: 2px solid rgba(255, 145, 77, 0.3);
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.sector-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

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

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

.sector-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(8, 32, 52, 1) 0%, rgba(10, 38, 60, 0.85) 40%, transparent 75%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  text-align: center;
  padding: var(--space-xl);
  transition: background var(--transition-base);
}

.sector-card:hover .sector-overlay {
  background: transparent;
}

.sector-card h3 {
  font-size: 1.25rem;
  margin-bottom: var(--space-sm);
  transition: opacity var(--transition-base);
}

.sector-card p {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 500;
  margin: 0;
  transition: opacity var(--transition-base);
}

.sector-card:hover h3,
.sector-card:hover p {
  opacity: 0;
}

/* CTA Section */
.cta-section {
  text-align: center;
  padding: var(--space-2xl) 0;
  background: var(--bg-primary);
}

.cta-section h2 {
  margin-bottom: var(--space-md);
}

.cta-section p {
  font-size: 1.125rem;
  margin-bottom: var(--space-xl);
}

/* Responsive */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .product-card { grid-template-columns: 1fr; }
  .product-card.reverse { direction: ltr; }
  .sector-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .menu-toggle { display: block; }
  .main-nav .btn-primary { display: none; }
  
  .nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    padding: var(--space-lg);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
  }
  
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .sector-grid { grid-template-columns: 1fr; }
  
  .post-card {
    grid-template-columns: 1fr;
  }
  
  .hero h1 {
    font-size: 2rem;
  }

  .hero-logo {
    max-width: 90%;
  }

  .hero-subtitle {
    font-size: 1.25rem;
  }

  .hero {
    min-height: 70vh;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
}

/* Back to top button */
.back-to-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 44px;
  height: 44px;
  background: var(--gradient-btn-primary);
  color: var(--bg-primary);
  border: 2px solid var(--accent-dark);
  border-radius: var(--radius-md);
  font-size: 1.5rem;
  font-weight: 900;
  line-height: 1;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity var(--transition-base), visibility var(--transition-base), transform var(--transition-base), box-shadow var(--transition-fast), border-color var(--transition-fast);
  box-shadow: var(--shadow-md);
  z-index: 999;
  -webkit-text-stroke: 2px var(--bg-primary);
  text-shadow: 0 1px 1px rgba(0,0,0,0.3);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--gradient-btn-primary-hover);
  border-color: var(--accent-hover);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.back-to-top:active {
  transform: translateY(0);
}

/* Utility classes */
.text-center { text-align: center; }
.no-border-bottom { border-bottom: none; }
.text-accent { color: var(--accent); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }