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

:root {
  --color-bg: #FFFFFF;
  --color-fg: #000000;
  --color-text: #1A1A1A;
  --color-text-secondary: #666666;
  --color-text-caption: #999999;
  --color-border: #E0E0E0;
  --font-heading: "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-body: "Helvetica Neue", Helvetica, Arial, sans-serif;
  --spacing-xs: 8px;
  --spacing-sm: 16px;
  --spacing-md: 32px;
  --spacing-lg: 64px;
  --spacing-xl: 128px;
  --max-width: 960px;
}

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

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-fg);
  text-decoration: none;
  transition: opacity 0.2s ease;
}

a:hover {
  opacity: 0.6;
}

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

header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-sm) var(--spacing-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  text-transform: lowercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  list-style: none;
}

.nav-links a {
  font-size: 0.875rem;
  letter-spacing: 0.01em;
}

.lang-switch {
  font-size: 0.875rem;
  padding: 4px 12px;
  border: 1px solid var(--color-fg);
  transition: background-color 0.2s ease, color 0.2s ease;
  cursor: pointer;
  background: none;
  font-family: var(--font-body);
  color: var(--color-fg);
}

.lang-switch:hover {
  background-color: var(--color-fg);
  color: var(--color-bg);
  opacity: 1;
}

.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-fg);
  margin: 4px 0;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(4px, 4px);
}

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

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

.mobile-menu {
  display: none;
  position: fixed;
  top: 53px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-bg);
  z-index: 99;
  padding: var(--spacing-md);
}

.mobile-menu.active {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.mobile-menu a {
  font-size: 1.25rem;
  font-weight: 500;
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-border);
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.hero {
  padding: var(--spacing-xl) 0 var(--spacing-lg);
  text-align: center;
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--spacing-sm);
}

.hero p {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto var(--spacing-md);
  line-height: 1.6;
}

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

.btn {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 12px 32px;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease;
  text-align: center;
}

.btn-primary {
  background-color: var(--color-fg);
  color: var(--color-bg);
  border: 1px solid var(--color-fg);
}

.btn-primary:hover {
  opacity: 0.85;
}

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

.btn-outline:hover {
  background-color: var(--color-fg);
  color: var(--color-bg);
  opacity: 1;
}

.products {
  padding: var(--spacing-lg) 0;
}

.products h2 {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-caption);
  margin-bottom: var(--spacing-md);
}

.product-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
}

.product-card {
  border: 1px solid var(--color-border);
  padding: var(--spacing-md);
  transition: border-color 0.2s ease;
}

.product-card:hover {
  border-color: var(--color-fg);
}

.product-card:hover a {
  opacity: 1;
}

.product-card h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: var(--spacing-xs);
}

.product-card p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin-bottom: var(--spacing-sm);
}

.product-card .card-link {
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.product-card .card-link::after {
  content: "→";
}

.section {
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--color-border);
}

.section h2 {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-caption);
  margin-bottom: var(--spacing-md);
}

.feature-list {
  list-style: none;
  display: grid;
  gap: var(--spacing-sm);
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-sm);
  font-size: 0.9375rem;
  line-height: 1.5;
}

.feature-list li::before {
  content: "—";
  flex-shrink: 0;
  color: var(--color-text-caption);
}

.steps {
  list-style: none;
  counter-reset: step;
  display: grid;
  gap: var(--spacing-sm);
}

.steps li {
  counter-increment: step;
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-sm);
  font-size: 0.9375rem;
  line-height: 1.5;
}

.steps li::before {
  content: counter(step, decimal-leading-zero);
  flex-shrink: 0;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--color-text-caption);
  min-width: 24px;
}

.cta-section {
  padding: var(--spacing-lg) 0;
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.cta-section p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-sm);
}

.faq {
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--color-border);
}

.faq h2 {
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-caption);
  margin-bottom: var(--spacing-md);
}

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

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: var(--spacing-sm) 0;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-question::after {
  content: "+";
  font-size: 1.25rem;
  font-weight: 300;
  color: var(--color-text-caption);
  transition: transform 0.2s ease;
}

.faq-item.active .faq-question::after {
  content: "−";
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-answer p {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  padding-bottom: var(--spacing-sm);
}

.faq-item.active .faq-answer {
  max-height: 300px;
}

.page-hero {
  padding: var(--spacing-lg) 0 var(--spacing-md);
}

.page-hero h1 {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--spacing-sm);
}

.page-hero .subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  max-width: 560px;
  line-height: 1.6;
}

.breadcrumb {
  font-size: 0.75rem;
  color: var(--color-text-caption);
  margin-bottom: var(--spacing-sm);
  display: flex;
  gap: 8px;
  align-items: center;
}

.breadcrumb a {
  color: var(--color-text-caption);
}

.breadcrumb span {
  color: var(--color-text-caption);
}

footer {
  border-top: 1px solid var(--color-border);
  margin-top: var(--spacing-lg);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.footer-inner p {
  font-size: 0.75rem;
  color: var(--color-text-caption);
}

.footer-links {
  display: flex;
  gap: var(--spacing-sm);
  list-style: none;
}

.footer-links a {
  font-size: 0.75rem;
  color: var(--color-text-caption);
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .hamburger {
    display: block;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .page-hero h1 {
    font-size: 1.75rem;
  }

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

  .hero-ctas {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

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