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

/* Custom Properties */
:root {
  --color-orange: #F97316;
  --color-orange-hover: #EA580C;
  --color-orange-light: #FFEDD5;
  --color-orange-dark: #FB923C;
  --color-bg: #FAFAFA;
  --color-surface: #FFFFFF;
  --color-text: #111111;
  --color-gray-400: #9CA3AF;
  --color-gray-500: #6B7280;
  --color-gray-900: #111827;
  --color-border: #E5E7EB;
  --color-slate-400: #94A3B8;
  --color-slate-500: #64748B;
  --color-slate-800: #1E293B;
  --color-slate-900: #0F172A;
  --max-width: 64rem; /* 1024px / 5xl */
}

/* Base */
html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', system-ui, sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.5;
}

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

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  transition: background-color 0.3s ease, border-color 0.3s ease, backdrop-filter 0.3s ease;
  border-bottom: 1px solid transparent;
}

.header.header-scrolled {
  background-color: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom-color: var(--color-border);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-logo {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--color-gray-900);
}

.header-nav {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-gray-500);
  transition: color 0.2s ease;
}

.header-nav:hover {
  color: var(--color-gray-900);
}

/* Hero */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
}

.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  width: 100%;
}

.hero-content {
  max-width: 42rem;
}

.hero-headline {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.1;
  color: var(--color-gray-900);
}

.hero-sub {
  margin-top: 1.5rem;
  font-size: 1.125rem;
  color: var(--color-gray-500);
  line-height: 1.625;
  max-width: 36rem;
}

.btn-primary {
  display: inline-block;
  margin-top: 2.5rem;
  padding: 0.875rem 2rem;
  background-color: var(--color-orange);
  color: white;
  font-weight: 500;
  border-radius: 0.5rem;
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.btn-primary:hover {
  background-color: var(--color-orange-hover);
  transform: scale(1.02);
}

/* Section shared */
.section {
  padding: 4rem 0;
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-gray-400);
  margin-bottom: 3rem;
}

/* Services */
.services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
}

.service-num {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-orange);
}

.service-title {
  margin-top: 0.75rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-gray-900);
}

.service-desc {
  margin-top: 0.75rem;
  color: var(--color-gray-500);
  line-height: 1.625;
}

/* Product */
.product-card {
  border: 1px solid var(--color-orange-light);
  border-radius: 1rem;
  background-color: var(--color-surface);
  padding: 2rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}

.product-label {
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-orange);
  margin-bottom: 1rem;
}

.product-title {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--color-gray-900);
}

.product-subtitle {
  margin-top: 0.25rem;
  font-size: 1.125rem;
  color: var(--color-gray-500);
}

.product-desc {
  margin-top: 1.25rem;
  color: var(--color-gray-500);
  line-height: 1.625;
}

.product-link {
  display: inline-flex;
  align-items: center;
  margin-top: 1.5rem;
  color: var(--color-orange);
  font-weight: 500;
  transition: color 0.2s ease;
}

.product-link:hover {
  color: var(--color-orange-hover);
}

.product-link svg {
  margin-left: 0.375rem;
  width: 1rem;
  height: 1rem;
  transition: transform 0.2s ease;
}

.product-link:hover svg {
  transform: translateX(2px);
}

.product-diagram {
  display: flex;
  justify-content: center;
}

.product-diagram svg {
  width: 100%;
  max-width: 20rem;
}

/* About */
.about-divider {
  border-top: 1px solid var(--color-border);
  padding-top: 4rem;
}

.about-content {
  max-width: 42rem;
  margin: 0 auto;
  text-align: center;
}

.about-text {
  color: var(--color-gray-500);
  line-height: 1.625;
  font-size: 1.125rem;
}

.about-tech {
  margin-top: 2rem;
  font-size: 0.875rem;
  color: var(--color-gray-400);
  letter-spacing: 0.05em;
}

/* Contact */
.contact {
  background-color: var(--color-slate-900);
  color: white;
}

.contact-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 6rem 1.5rem;
  text-align: center;
}

.contact-headline {
  font-size: 1.875rem;
  font-weight: 700;
  letter-spacing: -0.025em;
}

.contact-sub {
  margin-top: 1rem;
  color: var(--color-slate-400);
  font-size: 1.125rem;
}

.contact-email {
  display: inline-block;
  margin-top: 2rem;
  font-size: 1.25rem;
  color: var(--color-orange-dark);
  font-weight: 500;
  transition: color 0.2s ease;
}

.contact-email:hover {
  color: var(--color-orange-light);
}

/* Footer */
.footer {
  border-top: 1px solid var(--color-slate-800);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  font-size: 0.875rem;
  color: var(--color-slate-500);
  gap: 0.5rem;
}

/* Fade-in animation */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* Responsive */
@media (min-width: 640px) {
  .section {
    padding: 6rem 0;
  }

  .hero-headline {
    font-size: 3rem;
  }

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

  .product-card {
    padding: 3rem;
  }

  .product-title {
    font-size: 1.875rem;
  }

  .about-divider {
    padding-top: 6rem;
  }

  .contact-inner {
    padding: 8rem 1.5rem;
  }

  .contact-headline {
    font-size: 2.25rem;
  }

  .contact-email {
    font-size: 1.5rem;
  }

  .footer-inner {
    flex-direction: row;
    gap: 0;
  }
}

@media (min-width: 768px) {
  .hero-headline {
    font-size: 3.75rem;
  }

  .services-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 2.5rem;
  }
}

@media (min-width: 1024px) {
  .product-card {
    grid-template-columns: 1fr 1fr;
  }
}