/* === App Shell === */
#app {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

/* === App Loader (shown until auth check completes) === */
.app-loader {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-primary);
  z-index: 999;
}

.app-loader--hidden {
  display: none;
}

/* === Screens === */
.screen {
  position: absolute;
  inset: 0;
  display: none;
  flex-direction: column;
  pointer-events: none;
  overflow: hidden;
  z-index: var(--z-base);
}

.screen--active {
  display: flex;
  pointer-events: auto;
  z-index: 1;
}

/* === Screen Content === */
.screen__content {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  padding: var(--space-4);
  padding-top: calc(var(--safe-top) + var(--space-4));
  padding-bottom: calc(var(--bottom-bar-height) + var(--safe-bottom) + var(--space-4));
}

.screen__content--no-bar {
  padding-bottom: calc(var(--safe-bottom) + var(--space-4));
}

.screen__content--centered {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* === App Header === */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  padding: 0 var(--space-4);
  padding-top: var(--safe-top);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  z-index: var(--z-sticky);
  flex-shrink: 0;
}

.app-header__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
}

.app-header__back {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-accent);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  padding: var(--space-2);
  margin-left: calc(-1 * var(--space-2));
}

.app-header__action {
  padding: var(--space-2);
  color: var(--color-text-secondary);
}

/* === Bottom Tab Bar === */
.bottom-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: calc(var(--bottom-bar-height) + var(--safe-bottom));
  padding-bottom: var(--safe-bottom);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-top: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-around;
  align-items: center;
  z-index: var(--z-sticky);
}

.bottom-bar--hidden {
  display: none;
}

.bottom-bar__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  padding: var(--space-2) var(--space-4);
  transition: color var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
  position: relative;
}

.bottom-bar__item--active {
  color: var(--color-accent);
}

.bottom-bar__icon {
  width: 24px;
  height: 24px;
}

/* === FAB (Floating Action Button for Scan) === */
.bottom-bar__fab {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--color-accent);
  color: white;
  box-shadow: var(--shadow-glow);
  margin-top: -24px;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.bottom-bar__fab:active {
  transform: scale(0.92);
}

.bottom-bar__fab svg {
  width: 28px;
  height: 28px;
}

/* === Container === */
.container {
  width: 100%;
  max-width: var(--content-max-width);
  margin: 0 auto;
}