/* ============================================
   Layout — Nav, Containers, Grid
   ============================================ */

/* === Top Navigation === */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 1000;
  display: flex;
  align-items: center;
  padding: 0 var(--space-6);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
  margin-right: var(--space-8);
}

.nav-logo-text {
  font-size: var(--text-sm);
  font-weight: var(--weight-bold);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--color-text-primary);
  white-space: nowrap;
}

.nav-logo-accent {
  color: var(--color-accent);
}

.nav-f1-logo {
  flex-shrink: 0;
  height: 20px;
  width: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex: 1;
}

.nav-link {
  position: relative;
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--color-text-primary);
}

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

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: var(--space-4);
  right: var(--space-4);
  height: 3px;
  background: var(--color-accent);
  border-radius: 3px 3px 0 0;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
  flex-shrink: 0;
}

.nav-icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-icon-btn:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-hover);
}

.nav-icon-btn svg {
  width: 20px;
  height: 20px;
}

.nav-user-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3) var(--space-1) var(--space-1);
  border-radius: var(--radius-full);
  transition: background var(--transition-fast);
}

.nav-user-btn:hover {
  background: var(--color-bg-hover);
}

.nav-avatar {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  background: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-sm);
  font-weight: var(--weight-bold);
  color: white;
}

.nav-user-name {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
}

/* Hamburger (mobile) */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: 8px;
  border-radius: var(--radius-md);
  transition: background var(--transition-fast);
}

.nav-hamburger:hover {
  background: var(--color-bg-hover);
}

.nav-hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text-primary);
  border-radius: 1px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile drawer */
.nav-drawer {
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg-secondary);
  z-index: 999;
  padding: var(--space-4);
  flex-direction: column;
  gap: var(--space-1);
  overflow-y: auto;
  transform: translateX(100%);
  opacity: 0;
  transition: transform 250ms ease, opacity 200ms ease;
  display: flex;
  pointer-events: none;
}

.nav-drawer.open {
  transform: translateX(0);
  opacity: 1;
  pointer-events: auto;
}

.nav-drawer .nav-link {
  font-size: var(--text-md);
  padding: var(--space-4);
  border-radius: var(--radius-md);
}

.nav-drawer .nav-link:hover {
  background: var(--color-bg-hover);
}

.nav-drawer .nav-link.active::after {
  display: none;
}

.nav-drawer .nav-link.active {
  background: var(--color-accent-muted);
  color: var(--color-accent);
}

.nav-drawer-divider {
  height: 1px;
  background: var(--color-divider);
  margin: var(--space-3) 0;
}

/* User dropdown */
.user-dropdown {
  position: absolute;
  top: calc(var(--nav-height) - 4px);
  right: var(--space-6);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  min-width: 200px;
  padding: var(--space-2);
  z-index: 1001;
  display: none;
}

.user-dropdown.open {
  display: block;
}

.user-dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background var(--transition-fast);
  width: 100%;
}

.user-dropdown-item:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-hover);
}

.user-dropdown-item svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.user-dropdown-divider {
  height: 1px;
  background: var(--color-divider);
  margin: var(--space-2) var(--space-4);
}

/* === Page Container === */
.page-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: calc(var(--nav-height) + var(--space-8)) var(--space-6) var(--space-12);
}

.page-container-narrow {
  max-width: var(--container-narrow);
}

/* === Sub-Navigation (tabs) === */
.sub-nav {
  display: flex;
  gap: var(--space-1);
  margin-bottom: var(--space-6);
  border-bottom: 1px solid var(--color-border);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.sub-nav::-webkit-scrollbar {
  display: none;
}

.sub-nav-item {
  position: relative;
  padding: var(--space-3) var(--space-5);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--color-text-muted);
  white-space: nowrap;
  transition: color var(--transition-fast);
  flex-shrink: 0;
}

.sub-nav-item:hover {
  color: var(--color-text-secondary);
}

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

.sub-nav-item.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-accent);
}

/* === Grid Utilities === */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-4);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
}

/* === Flex Utilities === */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

/* === Spacing Utilities === */
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }

/* === Tab content === */
.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeIn var(--transition-base);
}

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

/* === Page transitions === */
.page-view {
  animation: pageIn 300ms ease both;
}

#app.page-exit {
  opacity: 0;
  transition: opacity 120ms ease;
}

@keyframes pageIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}