.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-bg);
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
}

.logo img {
  height: 42px;
  width: auto;
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text);
  padding: 6px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

.nav a:hover,
.nav a.active {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 26px;
  height: 3px;
  background: var(--color-primary);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

.hamburger.open span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

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

.hamburger.open span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

@media (max-width: 767px) {
  .hamburger {
    display: flex;
  }

  .nav {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    flex-direction: column;
    gap: 0;
    padding: 20px 0;
    transform: translateX(100%);
    transition: transform 0.3s ease;
    overflow-y: auto;
  }

  .nav.open {
    transform: translateX(0);
  }

  .nav a {
    display: block;
    width: 100%;
    padding: 16px 24px;
    font-size: 1.1rem;
    border-bottom: 1px solid var(--color-gray);
  }

  .nav a.active {
    border-bottom-color: var(--color-accent);
    background: rgba(43,108,176,0.05);
  }
}