.site-header {
  position: sticky;
  z-index: 1000;
  top: 0;
  width: 100%;
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  border-bottom: 1px solid transparent;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease,
    background-color 0.2s ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--border);
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.04);
}

.header-container {
  width: min(calc(100% - 40px), var(--container));
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  margin: 0 auto;
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
}

.site-brand-icon {
  width: 42px;
  height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 13px;
  background:
    linear-gradient(
      135deg,
      var(--primary) 0%,
      var(--primary-dark) 58%,
      var(--primary-deep) 100%
    );
  color: #ffffff;
  font-size: 1.15rem;
  font-weight: 800;
  line-height: 1;
  box-shadow: 0 12px 30px rgba(1, 162, 0, 0.2);
}

.site-brand-name {
  color: var(--text);
  font-size: 1.42rem;
  font-weight: 800;
  letter-spacing: -0.05em;
}

.primary-navigation {
  display: flex;
  align-items: center;
  gap: 30px;
}

.primary-navigation a {
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 600;
  transition: color 0.2s ease;
}

.primary-navigation a:hover {
  color: var(--primary-dark);
}

.primary-navigation .header-register-button {
  padding: 10px 18px;
  border-radius: 12px;
  background: var(--primary);
  color: #ffffff;
  font-weight: 700;
  box-shadow: 0 10px 24px rgba(1, 162, 0, 0.18);
}

.primary-navigation .header-register-button:hover {
  background: var(--primary-dark);
  color: #ffffff;
}

.mobile-menu-button {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #ffffff;
  cursor: pointer;
}

.mobile-menu-button span {
  width: 19px;
  height: 2px;
  border-radius: 999px;
  background: var(--text);
  transition:
    transform 0.2s ease,
    opacity 0.2s ease;
}

.mobile-menu-button[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.mobile-menu-button[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-button[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 760px) {
  .header-container {
    width: min(calc(100% - 32px), var(--container));
  }

  .site-brand-icon {
    width: 39px;
    height: 39px;
    border-radius: 12px;
  }

  .site-brand-name {
    font-size: 1.3rem;
  }

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

  .primary-navigation {
    position: fixed;
    top: calc(var(--header-height) - 1px);
    right: 0;
    left: 0;
    display: flex;
    align-items: stretch;
    flex-direction: column;
    gap: 6px;
    padding: 18px 16px 24px;
    border-bottom: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-medium);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-12px);
    pointer-events: none;
    transition:
      opacity 0.2s ease,
      transform 0.2s ease,
      visibility 0.2s ease;
  }

  .primary-navigation.is-open {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
  }

  .primary-navigation a {
    width: 100%;
    padding: 13px 15px;
    border-radius: 10px;
  }

  .primary-navigation a:hover {
    background: var(--primary-soft);
  }

  .primary-navigation .header-register-button {
    margin-top: 4px;
    text-align: center;
  }
}