/* ==========================================================================
   BillApp — layout.css
   App shell: header, screen container, bottom navigation.
   ========================================================================== */

#app {
  min-height: 100%;
  display: flex;
  flex-direction: column;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 20;
  height: calc(var(--header-height) + var(--safe-top));
  padding-top: var(--safe-top);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding-left: var(--space-4);
  padding-right: var(--space-4);
  background: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow-sm);
}

.app-header__back {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 0;
  background: transparent;
  border-radius: var(--radius-pill);
  flex-shrink: 0;
  margin-left: -4px;
}

.app-header__back:active {
  background: rgba(255, 255, 255, 0.15);
}

.app-header__title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.app-header__actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding-bottom: calc(var(--bottom-nav-height) + var(--safe-bottom));
  min-height: 0;
}

.screen {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: var(--space-4);
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  box-sizing: border-box;
}

.screen--flush {
  padding: 0;
  max-width: none;
}

.bottom-nav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 30;
  height: calc(var(--bottom-nav-height) + var(--safe-bottom));
  padding-bottom: var(--safe-bottom);
  display: flex;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  box-shadow: 0 -2px 10px rgba(15, 23, 42, 0.06);
}

.bottom-nav__item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  border: 0;
  background: transparent;
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
  padding: var(--space-1) 0;
}

.bottom-nav__item svg {
  width: 22px;
  height: 22px;
}

.bottom-nav__item.is-active {
  color: var(--color-primary);
}

.bottom-nav__item:active {
  transform: scale(0.94);
}

@media (min-width: 720px) {
  .screen {
    padding: var(--space-6);
  }
}

/* Invoice preview chrome (the tap-to-reveal toolbar screen) -------------------- */
.preview-viewport {
  position: fixed;
  inset: 0;
  z-index: 50;
  background: #5c636b;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
}

.preview-viewport__scale-wrapper {
  transform-origin: top center;
  margin: 24px auto;
}

.preview-toolbar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 60;
  display: flex;
  justify-content: space-around;
  background: rgba(20, 26, 32, 0.94);
  padding: var(--space-2) var(--space-1) calc(var(--space-2) + var(--safe-bottom));
  transform: translateY(100%);
  opacity: 0;
  transition: transform var(--duration-base) var(--ease-standard), opacity var(--duration-base) var(--ease-standard);
  pointer-events: none;
}

.preview-toolbar.is-visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.preview-toolbar__btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  border: 0;
  background: transparent;
  color: #fff;
  font-size: 10.5px;
  padding: var(--space-1) var(--space-2);
  min-width: 52px;
}

.preview-toolbar__btn svg {
  width: 22px;
  height: 22px;
}

.preview-toolbar__btn:active {
  opacity: 0.7;
}

.preview-toolbar__btn:disabled {
  opacity: 0.35;
  pointer-events: none;
}

.preview-hint {
  position: fixed;
  top: calc(var(--space-5) + var(--safe-top));
  left: 50%;
  transform: translateX(-50%);
  z-index: 55;
  background: rgba(20, 26, 32, 0.85);
  color: #fff;
  font-size: var(--font-size-sm);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-pill);
  pointer-events: none;
  transition: opacity var(--duration-slow) var(--ease-standard);
}

@media print {
  .preview-viewport {
    position: static;
    background: none;
    overflow: visible;
  }
  .preview-viewport__scale-wrapper {
    margin: 0;
  }
  .preview-toolbar,
  .preview-hint {
    display: none !important;
  }
}