/* ===================================
   BioVolt - Electric Vehicle Battery Company
   Main Stylesheet
   =================================== */

/* --- CSS Custom Properties --- */
:root {
  /* Colors */
  --color-primary: #0D5C36;
  --color-primary-dark: #094428;
  --color-primary-light: #0F6B3F;
  --color-white: #ffffff;
  --color-black: #1a1a1a;
  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2937;
  --color-gray-900: #111827;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  --font-size-6xl: 3.75rem;

  /* 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;
  --spacing-4xl: 6rem;

  /* Border Radius */
  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 6px;
  --radius-xl: 6px;
  --radius-2xl: 6px;
  --radius-full: 4px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

  /* Transitions */
  --transition-fast: 100ms ease;
  --transition-base: 150ms ease;
  --transition-slow: 200ms ease;

  /* Container */
  --container-max: 1200px;
  --container-padding: 1.5rem;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-gray-800);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-gray-900);
}

h1 {
  font-size: var(--font-size-5xl);
  letter-spacing: -0.02em;
}

h2 {
  font-size: var(--font-size-4xl);
  letter-spacing: -0.01em;
}

h3 {
  font-size: var(--font-size-2xl);
}

h4 {
  font-size: var(--font-size-xl);
}

p {
  color: var(--color-gray-600);
}

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

/* --- Section Base --- */
.section {
  padding: var(--spacing-4xl) 0;
}

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

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

.section-header p {
  font-size: var(--font-size-lg);
  max-width: 600px;
  margin: 0 auto;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: 0.875rem 1.75rem;
  font-size: var(--font-size-base);
  font-weight: 600;
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
  white-space: nowrap;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

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

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-gray-800);
  border: 2px solid var(--color-gray-300);
}

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

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

.btn-white:hover {
  background-color: var(--color-gray-100);
  box-shadow: var(--shadow-lg);
}

.btn-sm {
  padding: 0.625rem 1.25rem;
  font-size: var(--font-size-sm);
}

/* --- Navigation --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--spacing-md) 0;
  background-color: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: all var(--transition-base);
}

.navbar.scrolled {
  background-color: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-md);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-logo {
  display: block;
  font-size: 0; /* Hide text if any remains */
}

.navbar-logo img {
  height: 40px;
  width: auto;
  display: block;
}

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

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

.navbar-links a {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-gray-600);
  transition: color var(--transition-fast);
}

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

.navbar-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--spacing-sm);
}

.navbar-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-gray-800);
  transition: all var(--transition-fast);
}

.navbar-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.navbar-toggle.active span:nth-child(2) {
  opacity: 0;
}

.navbar-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Hero Section --- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--spacing-4xl) var(--container-padding);
  background: linear-gradient(180deg, var(--color-gray-50) 0%, var(--color-white) 100%);
  position: relative;
}

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

.hero-title {
  margin-bottom: var(--spacing-md);
  display: flex;
  justify-content: center;
}

.hero-title img {
  max-width: 100%;
  height: auto;
  max-height: 95px; /* Adjust based on design needs */
}

.hero-slogan {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--spacing-lg);
  letter-spacing: 0.02em;
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--color-gray-600);
  margin-bottom: var(--spacing-2xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

.scroll-indicator {
  position: absolute;
  bottom: var(--spacing-2xl);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--color-gray-400);
  font-size: var(--font-size-sm);
  animation: float 2s ease-in-out infinite;
}

.scroll-indicator svg {
  width: 24px;
  height: 24px;
}

@keyframes float {
  0%, 100% {
    transform: translateX(-50%) translateY(0);
  }
  50% {
    transform: translateX(-50%) translateY(8px);
  }
}

/* --- Benefits Section --- */
.benefits {
  background-color: var(--color-white);
}

/* --- Products Showcase Slider --- */
.products-showcase {
  background-color: var(--color-gray-50);
}

.showcase-slider {
  position: relative;
  overflow: hidden;
}

.showcase-track {
  display: flex;
  gap: var(--spacing-xl);
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.showcase-slide {
  flex: 0 0 calc(33.333% - var(--spacing-xl) * 2 / 3);
  min-width: 0;
}

.showcase-slide .product-card {
  height: 100%;
}

.showcase-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 48px;
  height: 48px;
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-gray-600);
  cursor: pointer;
  transition: all var(--transition-base);
  z-index: 10;
  box-shadow: var(--shadow-md);
}

.showcase-arrow:hover {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-50%) scale(1.05);
}

.showcase-arrow:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.showcase-arrow:disabled:hover {
  background-color: var(--color-white);
  border-color: var(--color-gray-200);
  color: var(--color-gray-600);
  transform: translateY(-50%);
}

.showcase-arrow svg {
  width: 24px;
  height: 24px;
}

.showcase-arrow-prev {
  left: var(--spacing-sm);
}

.showcase-arrow-next {
  right: var(--spacing-sm);
}

.showcase-dots {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-xl);
}

.showcase-dot {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-full);
  background-color: var(--color-gray-300);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  padding: 0;
}

.showcase-dot:hover {
  background-color: var(--color-gray-400);
}

.showcase-dot.active {
  background-color: var(--color-primary);
  width: 24px;
}

.showcase-cta {
  text-align: center;
  margin-top: var(--spacing-2xl);
}

/* Responsive slider */
@media (max-width: 1024px) {
  .showcase-slide {
    flex: 0 0 calc(50% - var(--spacing-xl) / 2);
  }
}

@media (max-width: 768px) {
  .showcase-slide {
    flex: 0 0 100%;
  }
  
  .showcase-arrow {
    width: 40px;
    height: 40px;
  }
  
  .showcase-arrow svg {
    width: 20px;
    height: 20px;
  }
  
  .showcase-arrow-prev {
    left: var(--spacing-xs);
  }
  
  .showcase-arrow-next {
    right: var(--spacing-xs);
  }
}

.benefits-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-xl);
}

.benefit-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
  padding: var(--spacing-xl);
  position: relative;
  overflow: hidden;
  transition: all var(--transition-base);
}

.benefit-card:hover {
  box-shadow: var(--shadow-lg);
}

.benefit-icon {
  width: 56px;
  height: 56px;
  background-color: rgba(22, 142, 80, 0.1);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-lg);
}

.benefit-icon svg {
  width: 28px;
  height: 28px;
  color: var(--color-primary);
}

.benefit-card h3 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-sm);
}

.benefit-card p {
  font-size: var(--font-size-sm);
  color: var(--color-gray-500);
}

/* --- Timeline Section (How to Order) --- */
.timeline {
  background-color: var(--color-gray-50);
}

.timeline-container {
  max-width: 700px;
  margin: 0 auto;
}

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

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

.timeline-item::before {
  content: '';
  position: absolute;
  left: 23px;
  top: 48px;
  bottom: 0;
  width: 2px;
  background-color: var(--color-gray-200);
}

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

.timeline-number {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  background-color: var(--color-primary);
  color: var(--color-white);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-lg);
  font-weight: 700;
  position: relative;
  z-index: 1;
}

.timeline-content {
  flex: 1;
  padding-top: var(--spacing-sm);
}

.timeline-content h3 {
  margin-bottom: var(--spacing-sm);
}

.timeline-content p {
  font-size: var(--font-size-sm);
}

/* --- For Whom Section --- */
.for-whom {
  background-color: var(--color-white);
}

.for-whom-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-xl);
}

.for-whom-card {
  background-color: var(--color-gray-50);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  text-align: center;
  transition: all var(--transition-base), 
              transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.for-whom-card:hover {
  background-color: var(--color-white);
  box-shadow: var(--shadow-lg);
}

.for-whom-icon {
  width: 72px;
  height: 72px;
  background-color: var(--color-white);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-lg);
  box-shadow: var(--shadow-md);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow var(--transition-base);
}

.for-whom-card:hover .for-whom-icon {
  box-shadow: var(--shadow-lg);
}

.for-whom-icon svg {
  width: 36px;
  height: 36px;
  color: var(--color-primary);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}


.for-whom-card h3 {
  margin-bottom: var(--spacing-sm);
}

/* --- CTA Section --- */
.cta {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-white);
  text-align: center;
  padding: var(--spacing-4xl) var(--container-padding);
}

.cta h2 {
  color: var(--color-white);
  margin-bottom: var(--spacing-md);
}

.cta p {
  color: rgba(255, 255, 255, 0.9);
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-xl);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

/* --- FAQ Section --- */
.faq {
  background-color: var(--color-white);
}

.faq-container {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--color-gray-200);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg) 0;
  text-align: left;
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-gray-900);
  transition: color var(--transition-fast);
}

.faq-question:hover {
  color: var(--color-primary);
}

.faq-question svg {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  color: var(--color-gray-400);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1), 
              color var(--transition-fast);
}

.faq-item.active .faq-question svg {
  transform: rotate(180deg);
  color: var(--color-primary);
}

.faq-answer {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.faq-item.active .faq-answer {
  grid-template-rows: 1fr;
}

.faq-answer-content {
  overflow: hidden;
  color: var(--color-gray-600);
  opacity: 0;
  transform: translateY(-10px);
  transition: opacity 0.3s ease 0.1s, 
              transform 0.3s ease 0.1s;
  padding-bottom: var(--spacing-lg);
}

.faq-item.active .faq-answer-content {
  opacity: 1;
  transform: translateY(0);
}

/* --- Footer --- */
.footer {
  background-color: var(--color-gray-900);
  color: var(--color-white);
  padding: var(--spacing-4xl) 0 var(--spacing-xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--spacing-3xl);
  margin-bottom: var(--spacing-3xl);
}

.footer-brand h3 {
  margin-bottom: var(--spacing-md);
  font-size: 0;
}

.footer-brand h3 img {
  height: 40px;
  width: auto;
  display: block;
}

.footer-brand p {
  color: var(--color-gray-400);
  font-size: var(--font-size-sm);
  max-width: 300px;
}

.footer-column h4 {
  color: var(--color-white);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-lg);
}

.footer-column ul {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer-column a {
  color: var(--color-gray-400);
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--color-gray-800);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-bottom p {
  color: var(--color-gray-500);
  font-size: var(--font-size-sm);
}

.footer-social {
  display: flex;
  gap: var(--spacing-md);
}

.footer-social a {
  width: 40px;
  height: 40px;
  background-color: var(--color-gray-800);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-gray-400);
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

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

/* --- Back to Top Button --- */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 48px;
  height: 48px;
  background-color: var(--color-primary);
  color: var(--color-white);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-base);
  z-index: 999;
}

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

.back-to-top:hover {
  background-color: var(--color-primary-dark);
  transform: translateY(-4px);
}

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

/* --- Products Page --- */
.products-hero {
  padding-top: 120px;
  padding-bottom: var(--spacing-2xl);
  background-color: var(--color-gray-50);
  text-align: center;
}

.products-hero h1 {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-sm);
}

.products-hero p {
  font-size: var(--font-size-lg);
}

.products-section {
  padding: var(--spacing-3xl) 0 var(--spacing-4xl);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-xl);
}

.product-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: all var(--transition-base);
}

.product-card:hover {
  box-shadow: var(--shadow-xl);
}

.product-image {
  aspect-ratio: 4/3;
  background-color: var(--color-gray-100);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

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

.product-image-placeholder {
  color: var(--color-gray-400);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
}

.product-image-placeholder svg {
  width: 48px;
  height: 48px;
}

.product-badge {
  position: absolute;
  top: var(--spacing-md);
  left: var(--spacing-md);
  background-color: var(--color-primary);
  color: var(--color-white);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-md);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.product-content {
  padding: var(--spacing-lg);
}

.product-content h3 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-md);
}

.product-specs {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.product-spec {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-sm);
  color: var(--color-gray-600);
}

.product-spec svg {
  width: 16px;
  height: 16px;
  color: var(--color-primary);
  flex-shrink: 0;
}

.product-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--color-gray-100);
}

.product-price {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-gray-900);
}

.product-price span {
  font-size: var(--font-size-sm);
  font-weight: 400;
  color: var(--color-gray-500);
}

/* --- Animations --- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.fade-in {
  opacity: 0;
}

.fade-in.visible {
  animation: fadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

.fade-in-left {
  opacity: 0;
}

.fade-in-left.visible {
  animation: fadeInLeft 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

.fade-in-right {
  opacity: 0;
}

.fade-in-right.visible {
  animation: fadeInRight 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* Staggered animation for cards */
.stagger-animation .fade-in:nth-child(1) { animation-delay: 0ms; }
.stagger-animation .fade-in:nth-child(2) { animation-delay: 100ms; }
.stagger-animation .fade-in:nth-child(3) { animation-delay: 200ms; }
.stagger-animation .fade-in:nth-child(4) { animation-delay: 300ms; }
.stagger-animation .fade-in:nth-child(5) { animation-delay: 400ms; }
.stagger-animation .fade-in:nth-child(6) { animation-delay: 500ms; }

/* Scale + fade animation variant */
.scale-fade-in {
  opacity: 0;
  transform: scale(0.95) translateY(20px);
  transition: opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1), 
              transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.scale-fade-in.visible {
  opacity: 1;
  transform: scale(1) translateY(0);
}

/* --- Responsive Design --- */
@media (max-width: 1024px) {
  .benefits-grid,
  .for-whom-grid,
  .products-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
  }

  .footer-brand {
    grid-column: span 2;
  }
}

@media (max-width: 768px) {
  :root {
    --container-padding: 1rem;
  }

  h1 {
    font-size: var(--font-size-4xl);
  }

  h2 {
    font-size: var(--font-size-3xl);
  }

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

  /* Navigation Mobile */
  .navbar-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 320px;
    height: 100vh;
    background-color: var(--color-white);
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    padding: var(--spacing-4xl) var(--spacing-xl);
    gap: var(--spacing-xl);
    box-shadow: var(--shadow-xl);
    transition: right var(--transition-base);
  }

  .navbar-menu.active {
    right: 0;
  }

  .navbar-links {
    flex-direction: column;
    align-items: flex-start;
    width: 100%;
  }

  .navbar-links a {
    font-size: var(--font-size-lg);
    padding: var(--spacing-sm) 0;
  }

  .navbar-toggle {
    display: flex;
    z-index: 1001;
  }

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

  /* Hero Mobile */
  .hero {
    min-height: 100dvh;
    padding-top: 80px; /* Reduced to compensate for centering with navbar */
    padding-bottom: var(--spacing-4xl);
  }

  .hero-title {
    font-size: clamp(2.5rem, 10vw, 3.5rem);
  }

  .scroll-indicator {
    display: none;
  }

  /* Benefits Mobile */
  .benefits-grid {
    grid-template-columns: 1fr;
  }

  /* For Whom Mobile */
  .for-whom-grid {
    grid-template-columns: 1fr;
  }

  /* Products Mobile */
  .products-grid {
    grid-template-columns: 1fr;
  }

  /* Footer Mobile */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  .footer-brand {
    grid-column: span 1;
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--spacing-md);
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }

  .hero-buttons .btn {
    width: 100%;
  }

  .product-footer {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-md);
  }

  .product-footer .btn {
    width: 100%;
  }

  .back-to-top {
    bottom: var(--spacing-md);
    right: var(--spacing-md);
    width: 40px;
    height: 40px;
  }
}

/* --- Mobile Menu Overlay --- */
.menu-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: 998;
}

.menu-overlay.active {
  opacity: 1;
  visibility: visible;
}