.app-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--color-header-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-header-border);
  box-shadow: var(--shadow-header);
  z-index: 1000;
}

.app-header__inner {
  width: min(var(--content-width), calc(100% - 32px));
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.brand {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 750;
  font-size: 1.04rem;
  letter-spacing: 0.01em;
}

.nav-list {
  display: flex;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  justify-content: flex-start;
  min-height: 24px;
  padding: 0;
  text-decoration: none;
  color: var(--color-text-soft);
  font-weight: 620;
  border-bottom: 2px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--color-primary);
  border-bottom-color: color-mix(in srgb, var(--color-primary) 35%, transparent);
  outline: none;
}

.nav-link.is-active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.theme-toggle {
  min-height: 32px;
  padding: 0 11px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-surface);
  color: var(--color-text-soft);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: border-color 0.18s ease, background-color 0.18s ease, color 0.18s ease;
}

.theme-toggle:hover {
  border-color: color-mix(in srgb, var(--color-primary) 42%, var(--color-border));
  color: var(--color-text);
}

.theme-toggle[aria-pressed="true"] {
  border-color: color-mix(in srgb, var(--color-primary) 40%, var(--color-border));
  background: color-mix(in srgb, var(--color-primary) 12%, var(--color-surface));
  color: var(--color-primary);
}

.theme-toggle:focus-visible {
  outline: none;
  box-shadow: var(--shadow-focus);
}

.page {
  width: min(var(--content-width), calc(100% - 32px));
  margin: 0 auto;
  flex: 1 0 auto;
  padding-top: calc(var(--header-height) + var(--space-6));
  padding-bottom: var(--space-7);
}

.page-collection-detail {
  padding-bottom: 120px;
}

.page-head {
  margin-bottom: var(--space-5);
}

.page-head h1 {
  font-size: clamp(1.55rem, 1.12rem + 1.2vw, 2.2rem);
  margin-bottom: var(--space-2);
}

.page-head p {
  max-width: 70ch;
  color: var(--color-text-soft);
}

.app-footer {
  margin-top: var(--space-4);
  border-top: 1px solid var(--color-footer-border);
  background: var(--color-footer-bg);
}

body[data-page="collection-detail"] .app-footer {
  border-top: 1px solid var(--color-footer-border);
  background: linear-gradient(180deg, color-mix(in srgb, var(--color-footer-bg) 75%, var(--color-surface) 25%) 0%, var(--color-footer-bg) 100%);
}

.app-footer__inner {
  width: min(var(--content-width), calc(100% - 32px));
  margin: 0 auto;
  padding: 14px 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

body[data-page="collection-detail"] .app-footer__inner {
  padding: 12px 0 14px;
}

.app-footer__nav {
  display: inline-flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.app-footer__nav a {
  font-size: 0.84rem;
  color: var(--color-footer-link);
  text-decoration: none;
}

.app-footer__nav a:hover,
.app-footer__nav a:focus-visible {
  color: var(--color-text);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--color-text) 28%, transparent);
  text-underline-offset: 2px;
}

.app-footer__meta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-footer-meta);
  font-size: 0.78rem;
  white-space: nowrap;
}

@media (max-width: 720px) {
  .app-header__inner,
  .page,
  .app-footer__inner {
    width: calc(100% - 24px);
  }

  .nav-link {
    min-height: 22px;
    padding: 0;
    font-size: 0.9rem;
  }

  .theme-toggle {
    min-height: 30px;
    padding: 0 10px;
    font-size: 0.75rem;
  }

  .app-footer__inner {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
    padding: 12px 0 14px;
  }

  .app-footer__nav {
    gap: var(--space-3);
  }

  .app-footer__meta {
    white-space: normal;
  }
}