/* =========================================
   Cubus Website - Styles
   Matching Vuexy/Bootstrap Design System
   ========================================= */

/* =========================================
   CSS Variables - Cubus Design System
   ========================================= */
:root {
  /* Brand Colors */
  --primary: #E42727;
  --primary-light: rgba(228, 39, 39, 0.12);
  --primary-dark: #c41f1f;

  /* Semantic Colors */
  --success: #28c76f;
  --info: #00cfe8;
  --warning: #ff9f43;
  --danger: #ea5455;

  /* Neutral Colors */
  --white: #ffffff;
  --light: #f8f8f8;
  --gray-100: #f6f6f6;
  --gray-200: #ededed;
  --gray-300: #dcdcdc;
  --gray-400: #b8c2cc;
  --gray-500: #6e6b7b;
  --gray-600: #5e5873;
  --gray-700: #4b4b4b;
  --gray-800: #2c2c2c;
  --gray-900: #1e1e1e;
  --dark: #2c2c2c;
  --black: #000000;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-size-base: 14px;
  --font-size-sm: 12px;
  --font-size-lg: 16px;
  --font-size-xl: 18px;

  /* Heading Sizes */
  --h1-size: 2.5rem;
  --h2-size: 2rem;
  --h3-size: 1.5rem;
  --h4-size: 1.25rem;
  --h5-size: 1.125rem;
  --h6-size: 1rem;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;

  /* Layout */
  --navbar-height: 4.45rem;
  --container-max-width: 1200px;
  --border-radius: 0.357rem;
  --border-radius-lg: 0.5rem;
  --border-radius-sm: 0.25rem;

  /* Shadows */
  --shadow-sm: 0 2px 4px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 24px 0 rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 25px -8px rgba(0, 0, 0, 0.15);

  /* Transitions */
  --transition: all 0.3s ease;
  --transition-fast: all 0.15s ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: var(--font-size-base);
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--gray-600);
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* =========================================
   Typography
   ========================================= */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--gray-800);
  margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--h1-size); }
h2 { font-size: var(--h2-size); }
h3 { font-size: var(--h3-size); }
h4 { font-size: var(--h4-size); }
h5 { font-size: var(--h5-size); }
h6 { font-size: var(--h6-size); }

p {
  margin-bottom: var(--spacing-md);
}

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

a:hover {
  color: var(--primary-dark);
}

/* =========================================
   Container & Layout
   ========================================= */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.section {
  padding: var(--spacing-3xl) 0;
}

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

.section-title {
  font-size: var(--h2-size);
  color: var(--gray-800);
  margin-bottom: var(--spacing-sm);
}

.section-subtitle {
  font-size: var(--font-size-lg);
  color: var(--gray-500);
  max-width: 600px;
  margin: 0 auto;
}

/* =========================================
   Grid System
   ========================================= */
.grid {
  display: grid;
  gap: var(--spacing-xl);
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

/* =========================================
   Buttons
   ========================================= */
.btn {
  display: inline-block;
  padding: 0.786rem 1.5rem;
  font-size: var(--font-size-base);
  font-weight: 500;
  line-height: 1.5;
  text-align: center;
  border: 1px solid transparent;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn-primary {
  background-color: var(--primary);
  color: var(--white);
  border-color: var(--primary);
}

.btn-primary:hover {
  background-color: var(--primary-dark);
  color: var(--white);
  box-shadow: 0 8px 25px -8px var(--primary);
  transform: translateY(-2px);
}

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

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

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

.btn-lg {
  padding: 1rem 2rem;
  font-size: var(--font-size-lg);
}

.btn-block {
  display: block;
  width: 100%;
}

/* =========================================
   Header & Navigation
   ========================================= */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--navbar-height);
  background-color: var(--white);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  transition: var(--transition);
}

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

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--navbar-height);
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

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

.brand-text {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary);
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  color: var(--gray-700);
}

.navbar-menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
}

.navbar-nav {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
  margin: 0;
}

.navbar-nav a {
  color: var(--gray-600);
  font-weight: 500;
  padding: var(--spacing-sm) 0;
  position: relative;
}

.navbar-nav a:hover {
  color: var(--primary);
}

.navbar-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary);
  transition: width 0.3s ease;
}

.navbar-nav a:hover::after {
  width: 100%;
}

.navbar-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.language-toggle {
  padding: 0.5rem 1rem;
  font-weight: 600;
  min-width: 50px;
}

/* =========================================
   Hero Section
   ========================================= */
.hero {
  margin-top: var(--navbar-height);
  padding: var(--spacing-3xl) 0;
  background: linear-gradient(135deg, var(--light) 0%, var(--white) 100%);
  text-align: center;
  min-height: 500px;
  display: flex;
  align-items: center;
  animation: fadeIn 0.8s ease-out;
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  color: var(--gray-800);
  margin-bottom: var(--spacing-md);
  animation: slideInUp 0.6s ease-out 0.2s both;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--gray-600);
  margin-bottom: var(--spacing-xl);
  line-height: 1.8;
  animation: slideInUp 0.6s ease-out 0.4s both;
}

.hero .btn {
  animation: slideInUp 0.6s ease-out 0.6s both;
}

/* =========================================
   Feature Cards
   ========================================= */
.feature-card, .element-card {
  background: var(--white);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  text-align: center;
}

.feature-card:hover, .element-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-5px);
}

.feature-icon, .element-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--spacing-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary-light);
  border-radius: var(--border-radius-lg);
  color: var(--primary);
}

.feature-icon svg, .element-icon svg {
  width: 32px;
  height: 32px;
}

.feature-title, .element-title {
  font-size: var(--h4-size);
  color: var(--gray-800);
  margin-bottom: var(--spacing-sm);
}

.feature-description, .element-description {
  color: var(--gray-600);
  line-height: 1.6;
}

/* =========================================
   AI Section
   ========================================= */
.ai-section {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.ai-section::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(228, 39, 39, 0.08) 0%, transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(0, 207, 232, 0.06) 0%, transparent 50%);
  pointer-events: none;
}

.ai-section .section-header {
  position: relative;
  z-index: 1;
}

.ai-section .section-title {
  color: var(--white);
}

.ai-section .section-subtitle {
  color: rgba(255, 255, 255, 0.7);
}

.ai-badge {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--primary);
  background-color: rgba(228, 39, 39, 0.15);
  border: 1px solid rgba(228, 39, 39, 0.3);
  padding: 0.35rem 1rem;
  border-radius: 2rem;
  margin-bottom: var(--spacing-md);
}

.ai-card {
  display: flex;
  gap: var(--spacing-lg);
  align-items: flex-start;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  transition: var(--transition);
  position: relative;
  z-index: 1;
}

.ai-card:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-5px);
}

.ai-card-icon {
  flex-shrink: 0;
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(228, 39, 39, 0.15);
  border-radius: var(--border-radius);
  color: var(--primary);
}

.ai-card-icon svg {
  width: 28px;
  height: 28px;
}

.ai-card-title {
  font-size: var(--h4-size);
  color: var(--white);
  margin-bottom: var(--spacing-sm);
}

.ai-card-description {
  color: rgba(255, 255, 255, 0.65);
  margin-bottom: 0;
  line-height: 1.6;
}

/* =========================================
   Sections - Alternating Backgrounds
   ========================================= */
.elements {
  background-color: var(--light);
}

.services {
  background-color: var(--light);
}

/* =========================================
   Timeline
   ========================================= */
.timeline-container {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
}

.timeline-item {
  display: flex;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-2xl);
  position: relative;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: 24px;
  top: 60px;
  bottom: -32px;
  width: 2px;
  background-color: var(--gray-300);
}

.timeline-item:last-child::before {
  display: none;
}

.timeline-marker {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background-color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
  position: relative;
  z-index: 1;
}

.timeline-number {
  color: var(--white);
  font-size: var(--font-size-lg);
  font-weight: 700;
}

.timeline-content {
  flex: 1;
  background: var(--white);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
}

.timeline-duration {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--primary);
  background-color: var(--primary-light);
  padding: 0.25rem 0.75rem;
  border-radius: var(--border-radius-sm);
  margin-bottom: var(--spacing-sm);
}

.timeline-title {
  font-size: var(--h4-size);
  color: var(--gray-800);
  margin-bottom: var(--spacing-sm);
}

.timeline-description {
  color: var(--gray-600);
  margin-bottom: 0;
}

/* =========================================
   Service Cards
   ========================================= */
.service-card {
  background: var(--white);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  gap: var(--spacing-lg);
  align-items: flex-start;
}

.service-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-5px);
}

.service-icon {
  flex-shrink: 0;
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary-light);
  border-radius: var(--border-radius);
  color: var(--primary);
}

.service-icon svg {
  width: 28px;
  height: 28px;
}

.service-title {
  font-size: var(--h4-size);
  color: var(--gray-800);
  margin-bottom: var(--spacing-sm);
}

.service-description {
  color: var(--gray-600);
  margin-bottom: 0;
}

/* =========================================
   Clients Section
   ========================================= */
.clients-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-xl);
  align-items: center;
  justify-content: center;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.client-logo {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-xl);
  background-color: var(--white);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  min-width: 200px;
  flex: 0 1 250px;
  min-height: 140px;
}

.client-logo:hover {
  box-shadow: var(--shadow);
  transform: translateY(-5px);
}

.client-logo img {
  max-width: 100%;
  max-height: 100px;
  width: auto;
  height: auto;
  object-fit: contain;
  opacity: 0.7;
  transition: var(--transition);
  filter: grayscale(100%);
}

.client-logo:hover img {
  opacity: 1;
  filter: grayscale(0%);
}

/* =========================================
   Contact Section
   ========================================= */
.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: var(--spacing-3xl);
  align-items: start;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.contact-item {
  display: flex;
  gap: var(--spacing-lg);
  align-items: flex-start;
}

.contact-icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary-light);
  border-radius: var(--border-radius);
  color: var(--primary);
}

.contact-icon svg {
  width: 24px;
  height: 24px;
}

.contact-details h4 {
  font-size: var(--font-size-lg);
  color: var(--gray-800);
  margin-bottom: 0.25rem;
}

.contact-details a,
.contact-details p {
  color: var(--gray-600);
  margin-bottom: 0;
}

.contact-details a:hover {
  color: var(--primary);
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-sm);
}

.social-link {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary-light);
  border-radius: var(--border-radius);
  color: var(--primary);
  transition: var(--transition);
}

.social-link:hover {
  background-color: var(--primary);
  color: var(--white);
  transform: translateY(-3px);
}

.social-link svg {
  width: 20px;
  height: 20px;
}

/* =========================================
   Contact Form
   ========================================= */
.contact-form-wrapper {
  background: var(--white);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow);
}

.form-group {
  position: relative;
  margin-bottom: var(--spacing-lg);
}

.form-control {
  width: 100%;
  padding: 0.875rem 1rem;
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--gray-700);
  background-color: var(--white);
  border: 1px solid var(--gray-300);
  border-radius: var(--border-radius);
  transition: var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
  transform: translateY(-2px);
}

.form-control:valid:not(:placeholder-shown) {
  border-color: var(--success);
}

.form-control:invalid:not(:placeholder-shown):not(:focus) {
  border-color: var(--danger);
}

.form-group label {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--gray-500);
  font-size: var(--font-size-base);
  pointer-events: none;
  transition: var(--transition-fast);
  background-color: var(--white);
  padding: 0 0.25rem;
}

.form-group textarea + label {
  top: 1rem;
  transform: none;
}

.form-control:focus + label,
.form-control:not(:placeholder-shown) + label {
  top: 0;
  font-size: var(--font-size-sm);
  color: var(--primary);
}

textarea.form-control {
  resize: vertical;
  min-height: 100px;
}

.form-check {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.form-check-input {
  margin-top: 0.25rem;
  cursor: pointer;
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.form-check-label {
  font-size: var(--font-size-sm);
  color: var(--gray-600);
  cursor: pointer;
  user-select: none;
}

/* =========================================
   Footer
   ========================================= */
.footer {
  background-color: var(--gray-900);
  color: var(--gray-400);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.footer-logo {
  height: 36px;
  width: auto;
  filter: brightness(0) invert(1);
}

.footer-brand .brand-text {
  color: var(--white);
}

.footer-links {
  display: flex;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--gray-400);
  transition: var(--transition-fast);
}

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

.footer-social span {
  display: block;
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-sm);
  color: var(--gray-400);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--gray-800);
  font-size: var(--font-size-sm);
}

.footer-bottom p {
  margin: 0;
}

/* =========================================
   Responsive Design
   ========================================= */

/* Tablet (768px and below) */
@media (max-width: 768px) {
  :root {
    --h1-size: 2rem;
    --h2-size: 1.75rem;
    --h3-size: 1.25rem;
  }

  .container {
    padding: 0 var(--spacing-md);
  }

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

  .section-header {
    margin-bottom: var(--spacing-2xl);
  }

  /* Mobile Navigation */
  .mobile-menu-toggle {
    display: block;
  }

  .navbar-menu {
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    right: 0;
    background-color: var(--white);
    flex-direction: column;
    align-items: stretch;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow);
    transform: translateX(-100%);
    transition: transform 0.3s ease;
  }

  .navbar-menu.active {
    transform: translateX(0);
  }

  .navbar-nav {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .navbar-actions {
    flex-direction: column;
    width: 100%;
  }

  .navbar-actions .btn {
    width: 100%;
  }

  /* Hero */
  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  /* Grid */
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }

  /* Timeline */
  .timeline-item {
    gap: var(--spacing-md);
  }

  .timeline-marker {
    width: 40px;
    height: 40px;
  }

  .timeline-item::before {
    left: 19px;
  }

  /* Service Cards & AI Cards */
  .service-card,
  .ai-card {
    flex-direction: column;
  }

  /* Contact */
  .contact-wrapper {
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
  }

  /* Footer */
  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    justify-content: center;
  }
}

/* Mobile (480px and below) */
@media (max-width: 480px) {
  .hero {
    padding: var(--spacing-2xl) 0;
    min-height: 400px;
  }

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

  .btn-lg {
    padding: 0.875rem 1.5rem;
    font-size: var(--font-size-base);
  }

  .clients-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .social-links {
    flex-wrap: wrap;
    justify-content: center;
  }
}

/* Large Desktop (1200px and above) */
@media (min-width: 1200px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }

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

/* =========================================
   Utility Classes
   ========================================= */
.text-center {
  text-align: center;
}

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

.bg-primary {
  background-color: var(--primary);
}

.bg-light {
  background-color: var(--light);
}

.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }

/* =========================================
   Animations
   ========================================= */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

/* Page load animation */
body {
  animation: fadeIn 0.3s ease-out;
}

/* Header animation */
.header {
  animation: slideInDown 0.5s ease-out;
}

/* =========================================
   Back to Top Button
   ========================================= */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 48px;
  height: 48px;
  background-color: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: scale(0);
  transition: all 0.3s ease;
  z-index: 999;
}

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

.back-to-top:hover {
  background-color: var(--primary-dark);
  transform: scale(1.1);
}

.back-to-top:active {
  transform: scale(0.95);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

/* =========================================
   Print Styles
   ========================================= */
@media print {
  .header,
  .footer,
  .btn,
  .social-links {
    display: none;
  }

  .hero {
    margin-top: 0;
  }

  * {
    box-shadow: none !important;
  }
}