/* ============================================================
   layout.css — App Header, Bottom Nav, Page Shell
   ============================================================ */

/* ── App Header ───────────────────────────────────────────── */
#app-header {
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: var(--max-width);
  height: var(--header-height);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-5);
  z-index: var(--z-sticky);
  padding-top: var(--safe-top);
  transition: background var(--transition-base);
}

.header__left  { display: flex; align-items: center; gap: var(--space-3); flex: 1; }
.header__right { display: flex; align-items: center; gap: var(--space-2); }

.header__title {
  font-size: var(--text-lg);
  font-weight: var(--font-semi);
  color: var(--color-text-primary);
  letter-spacing: -0.01em;
}

.header__subtitle {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.header__back {
  width: 36px; height: 36px;
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  color: var(--color-text-primary);
  transition: background var(--transition-fast);
  margin-left: calc(-1 * var(--space-2));
}

.header__back:active { background: var(--color-surface-2); }

.header__logo {
  height: 32px;
  width: auto;
  object-fit: contain;
}

.header__logo-text {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

/* Notification bell */
.header__notif-btn {
  position: relative;
}

.header__notif-badge {
  position: absolute;
  top: 4px; right: 4px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--color-danger);
  border: 2px solid var(--color-bg);
  display: none;
}

.header__notif-badge.visible { display: block; }

/* ── Bottom Navigation ────────────────────────────────────── */
#bottom-nav {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: var(--max-width);
  height: calc(var(--nav-height) + 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;
  align-items: flex-start;
  padding-top: var(--space-2);
  padding-bottom: var(--safe-bottom);
  z-index: var(--z-sticky);
}

.nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  padding: var(--space-1) 0;
  position: relative;
  text-decoration: none;
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}

.nav-item__icon {
  width: 26px; height: 26px;
  display: flex; align-items: center; justify-content: center;
  position: relative;
  transition: transform var(--transition-spring);
}

.nav-item__label {
  font-size: 10px;
  font-weight: var(--font-medium);
  letter-spacing: 0.01em;
  transition: color var(--transition-fast);
}

.nav-item__indicator {
  position: absolute;
  top: -2px; right: -2px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--color-danger);
  border: 2px solid var(--color-bg);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.nav-item.active {
  color: var(--color-primary);
}

.nav-item.active .nav-item__icon {
  transform: translateY(-2px);
}

.nav-item.has-badge .nav-item__indicator { opacity: 1; }

/* Active pill indicator */
.nav-item.active::before {
  content: '';
  position: absolute;
  top: -2px;
  width: 28px; height: 3px;
  background: var(--color-primary);
  border-radius: 0 0 4px 4px;
}

/* Touch ripple on nav tap */
.nav-item:active .nav-item__icon { transform: scale(0.88) translateY(-2px); }

/* ── Floating Action Button ───────────────────────────────── */
.fab {
  position: fixed;
  bottom: calc(var(--nav-height) + var(--safe-bottom) + var(--space-4));
  right: calc((100vw - min(100vw, var(--max-width))) / 2 + var(--space-5));
  width: 56px; height: 56px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow-primary);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  z-index: var(--z-above);
  transition: all var(--transition-spring);
  border: none;
}

.fab:active { transform: scale(0.92); }

/* ── Page ─────────────────────────────────────────────────── */
.page {
  min-height: 100%;
  display: flex;
  flex-direction: column;
}

.page-inner {
  padding: var(--space-4) var(--space-5);
  flex: 1;
}

/* ── Pull to Refresh Indicator ────────────────────────────── */
#pull-indicator {
  position: absolute;
  top: var(--header-height);
  left: 0; right: 0;
  height: 48px;
  display: flex; align-items: center; justify-content: center;
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  gap: var(--space-2);
  transform: translateY(-100%);
  transition: transform var(--transition-base);
  z-index: var(--z-above);
  pointer-events: none;
}

#pull-indicator.visible { transform: translateY(0); }

/* ── Overlay / Backdrop ───────────────────────────────────── */
.backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(4px);
  z-index: var(--z-overlay);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
}

.backdrop.visible {
  opacity: 1;
  pointer-events: all;
}

/* ── Bottom Sheet ─────────────────────────────────────────── */
.bottom-sheet {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%) translateY(100%);
  width: 100%;
  max-width: var(--max-width);
  background: var(--color-surface);
  border-radius: var(--radius-2xl) var(--radius-2xl) 0 0;
  z-index: var(--z-modal);
  transition: transform var(--transition-slow);
  padding-bottom: var(--safe-bottom);
  max-height: 85dvh;
  overflow-y: auto;
}

.bottom-sheet.open {
  transform: translateX(-50%) translateY(0);
}

.bottom-sheet__handle {
  width: 36px; height: 4px;
  border-radius: var(--radius-full);
  background: var(--color-border);
  margin: var(--space-3) auto var(--space-4);
}

/* ── Network Status Bar ───────────────────────────────────── */
#network-status {
  position: fixed;
  top: 0; left: 50%;
  transform: translateX(-50%);
  width: 100%; max-width: var(--max-width);
  background: var(--color-danger);
  color: #fff;
  text-align: center;
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  padding: var(--space-2);
  z-index: var(--z-top);
  transform: translateX(-50%) translateY(-100%);
  transition: transform var(--transition-base);
}

#network-status.offline { transform: translateX(-50%) translateY(0); }