/* Layout structure - lines and boxes behaving (mostly) */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.page-wrapper {
  min-height: 100vh;
  padding-top: var(--header-height);
  padding-bottom: calc(var(--tabbar-height) + var(--safe-area-inset-bottom));
}

/* Header */
.app-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  padding: var(--space-2) var(--space-4);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  background: rgba(246, 249, 247, 0.96);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(148, 163, 184, 0.24);
  z-index: var(--z-header);
}

.header-left,
.header-right {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.header-center {
  flex: 1;
  display: flex;
  align-items: center;
}

/* Bottom Navigation */
.bottom-tabbar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--tabbar-height);
  padding: var(--space-2) var(--space-4);
  padding-bottom: calc(var(--safe-area-inset-bottom) + var(--space-2));
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  align-items: center;
  gap: var(--space-2);
  background: rgba(246, 249, 247, 0.94);
  backdrop-filter: blur(14px);
  border-top: 1px solid rgba(148, 163, 184, 0.24);
  z-index: var(--z-header);
}

.tab-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2);
  color: var(--muted);
  font-size: var(--font-size-xs);
  transition: color var(--transition-fast);
  cursor: pointer;
  text-align: center;
  border-radius: var(--radius-sm);
}

.tab-item:hover {
  color: var(--brand-600);
  background: var(--surface-subtle);
}

.tab-item.active {
  color: var(--brand-600);
}

.tab-item svg {
  width: 24px;
  height: 24px;
  fill: currentColor;
}

/* FAB (Floating Action Button) */
.fab {
  position: fixed;
  left: 50%;
  bottom: calc(var(--tabbar-height) + var(--fab-gap) + var(--safe-area-inset-bottom));
  transform: translateX(-50%);
  width: var(--fab-size);
  height: var(--fab-size);
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--brand-500), var(--brand-700));
  color: white;
  border-radius: 50%;
  box-shadow: var(--shadow-elevated);
  z-index: var(--z-fab);
  border: 3px solid var(--bg);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.fab:hover {
  transform: translateX(-50%) scale(1.05);
  box-shadow: 0 20px 40px rgba(34, 179, 122, 0.25);
}

.fab:active {
  transform: translateX(-50%) scale(0.95);
}

.fab svg {
  width: 28px;
  height: 28px;
  fill: currentColor;
}

/* Grid layouts */
.grid {
  display: grid;
  gap: var(--space-4);
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-auto-fit {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

/* Flex utilities */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }

/* Stack layout */
.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.stack-sm {
  gap: var(--space-2);
}

.stack-lg {
  gap: var(--space-6);
}

/* Section */
.section {
  padding: var(--space-6) 0;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
}

/* Responsive */
@media (min-width: 640px) {
  .container {
    padding: 0 var(--space-6);
  }

  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--space-8);
  }
}