.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(11, 15, 26, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--transition-normal);
}

.site-header.scrolled {
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  flex-shrink: 0;
}

.logo-icon {
  width: 50px;
  height: auto;
}

.logo-name {
  font-size: var(--text-base);
  font-weight: var(--font-bold);
  color: var(--color-text-heading);
  letter-spacing: -0.02em;
}

.lang-toggle {
  display: flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  font-weight: var(--font-bold);
  background: var(--color-bg-input);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  flex-shrink: 0;
}

.lang-toggle:hover {
  background: var(--color-bg-hover);
  color: var(--color-text-primary);
  border-color: var(--color-border-accent);
}

.logo-tagline {
  font-size: 0.62rem;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.nav-link:hover { color: var(--color-text-primary); background: var(--color-bg-hover); }
.nav-link.active { color: var(--color-accent-light); background: var(--color-accent-glow); }

.nav-dropdown { position: relative; }

.nav-dropdown-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.nav-dropdown-btn:hover { color: var(--color-text-primary); background: var(--color-bg-hover); }

.chevron-icon {
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.nav-dropdown.open .chevron-icon { transform: rotate(180deg); }

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  left: auto;
  min-width: 240px;
  max-width: min(280px, calc(100vw - 24px));
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 24px rgba(0,0,0,0.35);
  padding: var(--space-2);
  display: none;
  z-index: 200;
  animation: fadeInScale 0.15s ease both;
  overflow-y: auto;
  max-height: calc(100dvh - var(--header-height) - 16px);
}

.nav-dropdown.open .nav-dropdown-menu { display: block; }

.nav-dropdown-menu a {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.nav-dropdown-menu a:hover { color: var(--color-text-primary); background: var(--color-bg-hover); }

.menu-icon { font-size: 1rem; flex-shrink: 0; margin-top: 2px; }
.menu-label { font-weight: var(--font-medium); color: var(--color-text-primary); display: block; }
.menu-desc { font-size: var(--text-xs); color: var(--color-text-muted); display: block; }
.dropdown-divider { height: 1px; background: var(--color-border); margin: var(--space-2) 0; }

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
  gap: 5px;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}

.menu-toggle:hover { background: var(--color-bg-hover); }

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text-primary);
  border-radius: 2px;
  transition: all var(--transition-normal);
}

.menu-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-nav {
  display: none;
  position: fixed;
  inset: var(--header-height) 0 0 0;
  background: var(--color-bg-primary);
  border-top: 1px solid var(--color-border);
  z-index: 99;
  overflow-y: auto;
  padding: var(--space-6);
  animation: fadeIn 0.2s ease;
}

.mobile-nav.open { display: block; }

.mobile-nav-section-title {
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: var(--space-4) var(--space-2) var(--space-2);
}

.mobile-nav-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.mobile-nav-links a {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.mobile-nav-links a:hover { color: var(--color-text-primary); background: var(--color-bg-hover); }

.page-wrapper {
  min-height: calc(100vh - var(--header-height));
  display: flex;
  flex-direction: column;
}

.page-main { flex: 1; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container-sm {
  max-width: 820px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.section { padding: var(--space-16) 0; }
.section-lg { padding: var(--space-20) 0; }
.section-sm { padding: var(--space-10) 0; }

.page-hero {
  background: linear-gradient(180deg, rgba(59,130,246,0.06) 0%, transparent 100%);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-12) 0 var(--space-10);
}

.page-hero-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
  font-size: var(--text-sm);
}

.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb a:hover { color: var(--color-accent-light); }
.breadcrumb-sep { color: var(--color-text-muted); }
.breadcrumb-current { color: var(--color-text-secondary); }

.page-hero-title {
  font-size: var(--text-4xl);
  font-weight: var(--font-extrabold);
  background: linear-gradient(135deg, #ffffff 40%, #93c5fd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-4);
  letter-spacing: -0.03em;
}

.page-hero-subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  line-height: 1.7;
}

.two-col-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  align-items: start;
}

.three-col-layout {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

.site-footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--space-12) 0 var(--space-8);
  margin-top: var(--space-20);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-10);
}

.footer-brand p {
  font-size: var(--text-sm);
  line-height: 1.7;
  max-width: 320px;
  margin-top: var(--space-3);
}

.footer-col-title {
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-4);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.footer-links {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
}

.footer-copy { font-size: var(--text-sm); color: var(--color-text-muted); }

@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  .site-nav { display: none; }
  .menu-toggle { display: flex; }
  .three-col-layout { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 700px) {
  .two-col-layout { grid-template-columns: 1fr; }
  .three-col-layout { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .page-hero-title { font-size: var(--text-3xl); }
  .container, .container-sm, .page-hero-content, .footer-inner, .header-inner {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
  }
}

@media (max-width: 480px) {
  .section { padding: var(--space-10) 0; }
  .section-lg { padding: var(--space-12) 0; }
  .page-hero { padding: var(--space-8) 0; }
}