:root {
  --color-primary: #0f172a;
  --color-accent: #2563eb;
  --color-text-muted: #64748b;
  --border-subtle: rgba(15, 23, 42, 0.08);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.8);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.site-header .container.nav {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 30px;
  box-sizing: border-box;
  gap: 12px;
  flex-wrap: wrap;
}

.site-header .logo {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  color: var(--color-primary);
  margin-right: 20px;
}

.site-header .logo-img {
  display: block;
  height: 36px;
  width: auto;
}

.site-header .nav-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 4px;
}

.site-header .menu-toggle {
  display: none;
  border: 1px solid var(--border-subtle);
  background: rgba(241, 245, 249, 0.95);
  color: var(--color-primary);
  border-radius: 10px;
  padding: 8px 10px;
  cursor: pointer;
  font-weight: 700;
  line-height: 1;
}

.site-header .nav-links.is-open {
  display: flex;
}

.site-header .nav-links a {
  position: relative;
  margin: 0 12px;
  padding-bottom: 4px;
  text-decoration: none;
  color: var(--color-primary);
  font-weight: 500;
  font-size: 15px;
  transition: color 0.2s ease;
}

.site-header .nav-links a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: #2563eb;
  transition: width 0.3s ease;
}

.site-header .nav-links a:hover {
  color: var(--color-accent);
}

.site-header .nav-links a:hover::after {
  width: 100%;
}

.site-header .nav-links a.active {
  font-weight: 700;
  color: var(--color-accent);
}

.site-header .nav-links a.active::after {
  width: 100%;
}

.site-header .lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 4px 6px;
  background: rgba(241, 245, 249, 0.95);
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.06);
}

.site-header .lang-switch a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 32px;
  padding: 6px 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--color-text-muted);
  text-decoration: none;
  line-height: 1;
  border-radius: 999px;
  transition: background 0.2s ease, color 0.2s ease, transform 0.15s ease;
}

.site-header .lang-switch a:hover {
  color: var(--color-accent);
  background: rgba(255, 255, 255, 0.95);
}

.site-header .lang-switch a.is-active {
  background: #fff;
  color: var(--color-accent);
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.1);
}

@media (max-width: 600px) {
  .site-header .container.nav {
    padding: 10px 16px;
    row-gap: 10px;
  }

  .site-header .logo-img {
    height: 28px;
  }

  .site-header .nav-links a {
    margin: 0 8px;
    font-size: 14px;
  }
}

@media (max-width: 767px) {
  .site-header .nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    gap: 6px 0;
    padding-top: 8px;
  }

  .site-header .nav-links.is-open {
    display: flex;
  }

  .site-header .menu-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-left: auto;
  }

  .site-header .nav-links a {
    margin: 0;
    padding: 8px 0;
  }
}

@media (min-width: 768px) {
  .site-header .nav-links {
    display: flex;
  }

  .site-header .menu-toggle {
    display: none;
  }
}