/* ===== RESET & BASE ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #818cf8;
  --secondary: #f97316;
  --secondary-dark: #ea580c;
  --secondary-light: #fb923c;
  --bg: #0f172a;
  --bg-alt: #1e293b;
  --bg-card: #1e293b;
  --text: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: #334155;
  --success: #22c55e;
  --error: #ef4444;
  --warning: #f59e0b;
  --radius: 12px;
  --radius-lg: 16px;
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.3), 0 2px 4px -2px rgba(0,0,0,0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.4), 0 4px 6px -4px rgba(0,0,0,0.4);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

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

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

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

/* ===== CONTAINER ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== HEADER ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 800;
  font-size: 1.25rem;
}

.logo-icon {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.875rem;
  font-weight: 800;
}

.logo-text {
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--secondary-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.main-nav {
  display: flex;
  gap: 0.25rem;
}

.nav-link {
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--text);
  background: rgba(99, 102, 241, 0.1);
  color: var(--primary-light);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== HERO ===== */
.hero {
  padding: 5rem 0 4rem;
  background: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(99, 102, 241, 0.15), transparent);
}

.hero-sm {
  padding: 3rem 0 2rem;
  text-align: center;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.hero p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin-bottom: 2rem;
}

.hero-sm p {
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.hero-visual {
  display: flex;
  gap: 1.5rem;
  margin-top: 3rem;
  flex-wrap: wrap;
}

.hero-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 600;
  font-size: 1.1rem;
  transition: var(--transition);
  animation: floatCard 3s ease-in-out infinite;
}

.hero-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: 0 0 30px rgba(99, 102, 241, 0.15);
}

.hero-card-1 {
  animation-delay: 0s;
}

.hero-card-2 {
  animation-delay: 1.5s;
}

.card-icon {
  font-size: 1.5rem;
}

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

/* ===== GRADIENT TEXT ===== */
.gradient-text {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
  color: white;
}

.btn-secondary {
  background: linear-gradient(135deg, var(--secondary) 0%, var(--secondary-dark) 100%);
  color: white;
}

.btn-secondary:hover {
  background: linear-gradient(135deg, var(--secondary-light) 0%, var(--secondary) 100%);
  color: white;
}

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

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary-light);
  background: rgba(99, 102, 241, 0.05);
}

.btn-block {
  width: 100%;
}

.btn-lg {
  padding: 0.875rem 2rem;
  font-size: 1rem;
}

/* ===== SECTIONS ===== */
.section {
  padding: 5rem 0;
}

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

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-header h2 {
  font-size: 2.25rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
}

.section-sub {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ===== PRODUCT CARDS ===== */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
  max-width: 900px;
  margin: 0 auto;
}

.product-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
  transition: var(--transition);
}

.product-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-lg), 0 0 40px rgba(99, 102, 241, 0.08);
}

.product-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
  padding: 0.25rem 1rem;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.product-badge-secondary {
  background: linear-gradient(135deg, var(--secondary) 0%, var(--secondary-dark) 100%);
}

.product-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.product-icon-lg {
  font-size: 4rem;
  text-align: center;
  margin-bottom: 1rem;
}

.product-card h3 {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.product-card h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  text-align: center;
}

.product-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1.25rem;
  line-height: 1.6;
}

.product-features {
  list-style: none;
  margin-bottom: 1.5rem;
}

.product-features li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.product-features li svg {
  color: var(--success);
  flex-shrink: 0;
}

.product-price {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  padding: 1rem 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.price-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.price-value {
  font-size: 1.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--secondary-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== CTA SECTION ===== */
.cta-section {
  padding: 4rem 0;
}

.cta-box {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15) 0%, rgba(249, 115, 22, 0.1) 100%);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: var(--radius-lg);
  padding: 3rem 2rem;
  text-align: center;
}

.cta-box h2 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
}

.cta-box p {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.cta-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== CHECKOUT LAYOUT ===== */
.checkout-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  max-width: 1000px;
  margin: 0 auto;
  align-items: start;
}

.checkout-product .product-card {
  text-align: center;
}

.form-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.form-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.checkout-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  color: var(--text);
  font-size: 0.95rem;
  font-family: inherit;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

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

.form-info {
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
  background: rgba(99, 102, 241, 0.05);
  border: 1px solid rgba(99, 102, 241, 0.15);
  border-radius: var(--radius);
  padding: 0.75rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.form-info svg {
  color: var(--primary-light);
  flex-shrink: 0;
  margin-top: 2px;
}

.form-total {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  border-top: 1px solid var(--border);
  font-weight: 600;
}

.total-price {
  font-size: 1.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--secondary-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== ALERTS ===== */
.alert {
  padding: 0.875rem 1rem;
  border-radius: var(--radius);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.alert-error {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: #fca5a5;
}

.alert-success {
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.3);
  color: #86efac;
}

/* ===== FOOTER ===== */
.site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 3rem 0 1.5rem;
  margin-top: 4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-col h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--secondary-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-col h4 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.footer-col p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
}

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

.footer-bottom {
  text-align: center;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ===== LOADING STATE ===== */
.btn.loading {
  position: relative;
  pointer-events: none;
  opacity: 0.85;
}

.btn.loading::after {
  content: '';
  position: absolute;
  width: 18px;
  height: 18px;
  border: 2px solid transparent;
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .main-nav {
    display: none;
  }

  .main-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 1rem;
    gap: 0.25rem;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .hero {
    padding: 3rem 0 2rem;
    text-align: center;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    justify-content: center;
  }

  .checkout-layout {
    grid-template-columns: 1fr;
  }

  .product-grid {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .cta-actions {
    flex-direction: column;
    align-items: center;
  }

  .section {
    padding: 3rem 0;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }

  .product-card {
    padding: 1.5rem;
  }

  .form-card {
    padding: 1.5rem;
  }

  .hero-card {
    padding: 1rem 1.5rem;
  }
}

/* ===== LIGHT MODE ===== */
body.light {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #6366f1;
  --secondary: #f97316;
  --secondary-dark: #ea580c;
  --secondary-light: #fb923c;
  --bg: #f8fafc;
  --bg-alt: #e2e8f0;
  --bg-card: #ffffff;
  --text: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border: #cbd5e1;
  --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.06);
}

body.light .site-header {
  background: rgba(248, 250, 252, 0.9);
}

body.light .nav-link {
  color: var(--text-secondary);
}

body.light .nav-link:hover,
body.light .nav-link.active {
  color: var(--primary);
  background: rgba(99, 102, 241, 0.08);
}

body.light .mobile-menu-btn span {
  background: var(--text);
}

body.light .product-card {
  box-shadow: var(--shadow);
}

body.light .cta-box {
  background: rgba(99, 102, 241, 0.05);
  border-color: rgba(99, 102, 241, 0.15);
}

body.light .form-group input,
body.light .form-group textarea {
  background: var(--bg);
}

body.light .form-info {
  background: rgba(99, 102, 241, 0.04);
  border-color: rgba(99, 102, 241, 0.1);
}

body.light .form-info svg {
  color: var(--primary);
}

body.light .site-footer {
  background: var(--bg-alt);
}

body.light .footer-col a:hover {
  color: var(--primary);
}

body.light .success-info {
  background: var(--bg-card);
}