.header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  background-color: rgba(11, 15, 25, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 1000;
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-normal);
}

[data-theme="light"] .header {
  background-color: rgba(248, 250, 252, 0.85);
}

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

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text-main);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0, "calt" 0;
}

.logo-accent {
  color: var(--accent-primary);
}

.logo-closing {
  margin-left: 0.32rem;
  letter-spacing: 0.12em;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-link {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link:hover,
.nav-link.active-link {
  color: var(--accent-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.theme-toggle,
.nav-toggle {
  background: transparent;
  border: none;
  font-size: 1.15rem;
  color: var(--text-main);
  cursor: pointer;
  padding: 0.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast);
}

.theme-toggle:hover,
.nav-toggle:hover {
  color: var(--accent-primary);
}

.nav-toggle {
  display: none;
}

@media screen and (max-width: 768px) {
  .nav-toggle {
    display: block;
  }

  .nav-menu {
    position: fixed;
    top: 70px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 70px);
    background-color: var(--bg-primary);
    padding: 2.5rem 1.5rem;
    transition: left var(--transition-normal);
    border-right: 1px solid var(--border-color);
  }

  .nav-menu.show-menu {
    left: 0;
  }

  .nav-list {
    flex-direction: column;
    gap: 1.5rem;
  }

  .nav-link {
    font-size: 1.15rem;
  }
}