/**
 * Layout Primitives: AppShell, PageContainer, ScreenHeader & Bottom Navigation
 * Responsive from 320px to 480px mobile portrait, centered on wide screens.
 */

/* ==========================================================================
   1. AppShell & Screen Container
   ========================================================================== */

.app-shell {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  width: 100%;
  transition: background-color var(--duration-normal) var(--ease-standard);
}

.page-container {
  width: 100%;
  max-width: var(--max-content-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
  padding-top: var(--space-3);
  padding-bottom: calc(var(--space-6) + var(--bottom-bar-height) + var(--safe-area-bottom));
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

/* Screen Switching (Game vs. Wallet) */
.screen-view {
  display: none;
  width: 100%;
  flex-direction: column;
  gap: var(--space-4);
  animation: fadeIn 200ms ease-out;
}

.screen-view.active {
  display: flex;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==========================================================================
   2. ScreenHeader / TopBar (Compact, Mobile-First)
   ========================================================================== */

.screen-header {
  position: sticky;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-header);
  background-color: var(--header-bg);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--color-border-subtle);
  padding-top: var(--safe-area-top);
  width: 100%;
  transition: background-color var(--duration-normal) var(--ease-standard),
              border-color var(--duration-normal) var(--ease-standard);
}

.screen-header-inner {
  max-width: var(--max-content-width);
  margin-left: auto;
  margin-right: auto;
  min-height: 52px;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

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

.brand-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-fg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: var(--font-weight-bold);
  font-size: 15px;
  box-shadow: 0 2px 6px var(--color-primary-glow);
  flex-shrink: 0;
}

.brand-info {
  display: flex;
  flex-direction: column;
}

.header-title {
  font-size: var(--font-size-subtitle);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  line-height: 1.25;
}

.header-subtitle {
  font-size: var(--font-size-caption);
  color: var(--color-text-muted);
  line-height: 1.25;
}

/* ==========================================================================
   3. Bottom Navigation Bar Foundation (Strict: 2 Tabs - Game & Wallet)
   ========================================================================== */

.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: var(--z-bottom-nav);
  background-color: var(--nav-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-top: 1px solid var(--color-border);
  padding-bottom: var(--safe-area-bottom);
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.08);
  transition: background-color var(--duration-normal) var(--ease-standard),
              border-color var(--duration-normal) var(--ease-standard);
}

.bottom-nav-inner {
  max-width: var(--max-content-width);
  margin-left: auto;
  margin-right: auto;
  height: var(--bottom-bar-height);
  display: grid;
  grid-template-columns: 1fr 1fr; /* Strict 2 Tabs: Game & Wallet */
  align-items: center;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
  gap: var(--space-3);
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  height: 52px;
  color: var(--color-text-muted);
  font-size: var(--font-size-label);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-md);
  transition: color var(--duration-fast) var(--ease-standard),
              background-color var(--duration-fast) var(--ease-standard),
              transform var(--duration-fast) var(--ease-standard);
  position: relative;
  background: transparent;
  border: none;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.nav-item:active {
  transform: scale(0.96);
}

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

.nav-item .nav-icon {
  width: 24px;
  height: 24px;
  stroke-width: 2.1;
  transition: transform var(--duration-fast) var(--ease-standard),
              stroke var(--duration-fast) var(--ease-standard);
}

.nav-item.active .nav-icon {
  transform: translateY(-1px);
}

/* Active Indicator Pill / Pip */
.nav-item.active::after {
  content: "";
  position: absolute;
  bottom: 2px;
  width: 16px;
  height: 3px;
  border-radius: var(--radius-full);
  background-color: var(--color-primary);
  box-shadow: 0 1px 4px var(--color-primary-glow);
}

/* ==========================================================================
   4. Utility Grid & Stack Classes
   ========================================================================== */

.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.stack-sm {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.stack-lg {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.row-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-3);
}