/* App shell: chrome + content */

.app-shell {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.app-header .btn,
.app-header .btn:hover,
.app-header .btn:visited,
.app-nav__link,
.app-nav__link:hover,
.app-nav__link:visited,
.app-brand,
.app-brand:hover,
.app-brand:visited {
  text-decoration: none;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  height: var(--header-height);
  background: linear-gradient(180deg, var(--color-chrome) 0%, var(--color-chrome-elevated) 100%);
  border-bottom: 1px solid var(--color-chrome-border);
  box-shadow: var(--shadow-chrome);
}

.app-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  height: 100%;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: 0 var(--shell-gutter);
}

.app-brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-chrome-ink);
  flex-shrink: 0;
}

.app-brand__logo {
  display: block;
  height: 1.75rem;
  width: auto;
  max-height: 1.75rem;
  max-width: min(100%, 5.5rem);
  object-fit: contain;
  object-position: left center;
  flex-shrink: 0;
  align-self: center;
}

.app-brand:hover,
.app-brand:visited {
  color: var(--color-chrome-ink);
  text-decoration: none;
}

.app-brand__mark {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: var(--weight-bold);
  letter-spacing: var(--tracking-tight);
  line-height: 1;
}

.app-brand__product {
  font-family: var(--font-sans);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--color-chrome-accent);
}

.app-nav-toggle {
  display: none;
  margin-inline-start: auto;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  border: 1px solid var(--color-chrome-border);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-chrome-ink);
}

.app-nav-toggle svg {
  width: 1.25rem;
  height: 1.25rem;
}

.app-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex: 1;
  min-width: 0;
}

.app-nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
  margin: 0;
  padding: 0;
}

.app-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: var(--space-2) var(--space-3);
  color: var(--color-chrome-muted);
  text-decoration: none;
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  letter-spacing: 0.01em;
  border-radius: var(--radius-sm);
  transition: color var(--duration-fast) var(--ease-soft);
}

.app-nav__link::after {
  content: "";
  position: absolute;
  left: var(--space-3);
  right: var(--space-3);
  bottom: 0.15rem;
  height: 2px;
  background: var(--color-chrome-accent);
  transform: scaleX(0);
  transform-origin: inline-start center;
  transition: transform var(--duration-base) var(--ease-out);
}

.app-nav__link:visited {
  color: var(--color-chrome-muted);
  text-decoration: none;
}

.app-nav__link:hover {
  color: var(--color-chrome-ink);
  text-decoration: none;
}

.app-nav__link:hover::after,
.app-nav__link.is-active::after {
  transform: scaleX(1);
}

.app-nav__link.is-active {
  color: var(--color-chrome-ink);
}

.app-header__meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-inline-start: auto;
  flex-shrink: 0;
}

.app-entity {
  display: none;
  flex-direction: column;
  align-items: flex-end;
  line-height: 1.2;
}

.app-entity__label {
  font-size: 0.625rem;
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--color-chrome-muted);
  font-weight: var(--weight-semibold);
}

.app-entity__value {
  font-size: var(--text-sm);
  color: var(--color-chrome-ink);
  font-weight: var(--weight-medium);
}

.app-main {
  flex: 1;
  width: 100%;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: var(--space-8) var(--shell-gutter) var(--space-16);
}

.app-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-5) var(--shell-gutter);
  color: var(--color-ink-muted);
  font-size: var(--text-xs);
  letter-spacing: 0.02em;
}

.app-footer__inner {
  max-width: var(--shell-max);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3) var(--space-6);
  justify-content: space-between;
}

/* Page enter motion */
.page-enter {
  animation: page-enter var(--duration-slow) var(--ease-out) both;
}

@keyframes page-enter {
  from {
    opacity: 0;
    transform: translateY(0.5rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-enter {
    animation: none;
  }

  .app-nav__link::after {
    transition: none;
  }
}

html[dir="rtl"] .app-brand__logo {
  object-position: right center;
}

html[dir="rtl"] .app-nav__link::after {
  transform-origin: right center;
}

@media (min-width: 900px) {
  .app-entity {
    display: flex;
  }
}

@media (max-width: 899px) {
  .app-nav-toggle {
    display: inline-flex;
  }

  .app-nav {
    position: fixed;
    inset: var(--header-height) 0 auto 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-4) var(--shell-gutter) var(--space-6);
    background: var(--color-chrome-elevated);
    border-bottom: 1px solid var(--color-chrome-border);
    box-shadow: var(--shadow-lg);
  }

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

  .app-nav__list {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
  }

  .app-nav__link {
    padding: var(--space-3) var(--space-4);
  }

  .app-nav__link::after {
    left: var(--space-4);
    right: auto;
    width: 1.25rem;
    bottom: 50%;
    transform: translateY(50%) scaleX(0);
    transform-origin: left center;
  }

  .app-nav__link.is-active::after,
  .app-nav__link:hover::after {
    transform: translateY(50%) scaleX(1);
  }

  .app-header__meta {
    display: none;
  }
}