.app-header {
  position: sticky;
  top: 0;
  z-index: 20;
  height: var(--header-height);
  display: flex;
  align-items: center;
  background: var(--color-primary);
  border-bottom: 2px solid var(--color-accent);
}

.app-header-inner {
  width: 100%;
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--space-5);
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.app-brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text-on-primary);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.01em;
  flex: none;
}

.app-brand:hover {
  text-decoration: none;
  opacity: 0.92;
}

.app-brand-mark {
  width: 24px;
  height: 24px;
  border-radius: 5px;
  background: var(--color-accent);
  color: #2a1e05;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.78rem;
  flex: none;
}

.app-nav {
  display: flex;
  gap: var(--space-1);
  flex: 1;
}

.app-nav a {
  color: rgba(244, 246, 248, 0.72);
  font-size: 0.86rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  transition: background-color 0.15s ease, color 0.15s ease;
}

.app-nav a:hover {
  color: var(--color-text-on-primary);
  text-decoration: none;
  background: rgba(244, 246, 248, 0.08);
}

.app-nav a[aria-current="page"] {
  color: var(--color-text-on-primary);
  background: rgba(244, 246, 248, 0.14);
}

.app-header-actions {
  flex: none;
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.app-nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid rgba(244, 246, 248, 0.3);
  color: var(--color-text-on-primary);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  cursor: pointer;
}

/* Theme toggle switch */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  flex: none;
}

.theme-toggle-track {
  position: relative;
  width: 40px;
  height: 22px;
  border-radius: 999px;
  background: rgba(244, 246, 248, 0.16);
  border: 1px solid rgba(244, 246, 248, 0.3);
  transition: background-color 0.15s ease;
}

.theme-toggle-thumb {
  position: absolute;
  top: 1px;
  left: 1px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-text-on-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.62rem;
  line-height: 1;
  transition: transform 0.18s ease;
}

.theme-toggle input:checked ~ .theme-toggle-track {
  background: var(--color-accent);
  border-color: var(--color-accent);
}

.theme-toggle input:checked ~ .theme-toggle-track .theme-toggle-thumb {
  transform: translateX(18px);
}

.theme-toggle input:focus-visible ~ .theme-toggle-track {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.app-main {
  width: 100%;
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: var(--space-6) var(--space-5) var(--space-8);
}

.page-header {
  margin-bottom: var(--space-6);
}

.page-header p {
  max-width: 60ch;
}

.app-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-5);
  text-align: center;
  color: var(--color-text-subtle);
  font-size: 0.78rem;
}

@media (max-width: 860px) {
  .app-header-inner {
    gap: var(--space-3);
    padding: 0 var(--space-3);
  }

  .app-brand {
    font-size: 0.9rem;
  }

  .app-header-actions {
    gap: var(--space-2);
  }

  .status-pill [data-connection-label] {
    display: none;
  }

  .status-pill {
    padding: 6px;
  }

  .app-header-actions .btn-sm {
    padding: 6px 10px;
    font-size: 0.76rem;
  }

  .app-nav-toggle {
    display: inline-flex;
  }

  .app-nav {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-primary);
    flex-direction: column;
    padding: var(--space-2);
    border-bottom: 2px solid var(--color-accent);
    display: none;
  }

  .app-nav.is-open {
    display: flex;
  }

  .app-header-inner {
    position: relative;
  }
}