/* Transitions and animations */

.nav-item,
.account-icon,
.btn,
.message-row {
  transition: background var(--transition-fast), color var(--transition-fast), opacity var(--transition-fast);
}

.message-row:hover {
  background: var(--bg-surface-hover);
}

/* Focus styles for accessibility */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.message-row:focus-visible,
.nav-item:focus-visible {
  outline-offset: -2px;
}

.message-row.is-focused {
  background: var(--bg-surface-hover);
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}

/* Skip to content link */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: var(--gray-13);
  z-index: 1000;
  font-weight: var(--weight-medium);
}

.skip-link:focus {
  top: 0;
}

/* ARIA-only text */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Keyboard shortcuts overlay */
.shortcuts-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  z-index: 999;
}

.shortcuts-dialog {
  background: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  max-width: 560px;
  width: 90vw;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

.shortcuts-dialog h3 {
  margin-bottom: 1rem;
  font-size: var(--text-lg);
}

.shortcuts-dialog h4 {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0.75rem 0 0.375rem;
}

.shortcuts-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.shortcuts-dialog dl {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.25rem 0.75rem;
  align-items: baseline;
  font-size: var(--text-sm);
}

.shortcuts-dialog dt {
  text-align: right;
}

.shortcuts-dialog dd {
  color: var(--text-secondary);
}

kbd {
  display: inline-block;
  padding: 0.1em 0.4em;
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--bg-surface-raised);
  border: 1px solid var(--border-default);
  border-radius: 3px;
  min-width: 1.5em;
  text-align: center;
}

.shortcuts-footer {
  margin-top: 1rem;
  text-align: center;
  font-size: var(--text-xs);
  color: var(--text-tertiary);
}

/* Smooth page transitions via htmx */
.htmx-swapping {
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.htmx-settling {
  opacity: 1;
  transition: opacity var(--transition-normal);
}

/* Loading indicator */
.htmx-request {
  position: relative;
}

.htmx-request::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
  animation: loading 1.5s ease-in-out infinite;
}

@keyframes loading {
  0% { transform: scaleX(0); transform-origin: left; }
  50% { transform: scaleX(1); transform-origin: left; }
  50.01% { transform-origin: right; }
  100% { transform: scaleX(0); transform-origin: right; }
}

/* Dark mode toggle component */
.theme-toggle {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.theme-toggle-track {
  width: 36px;
  height: 20px;
  border-radius: 10px;
  background: var(--border-default);
  position: relative;
  transition: background var(--transition-normal);
}

.theme-toggle-thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--text-primary);
  transition: transform var(--transition-normal);
}

[data-theme="light"] .theme-toggle-thumb {
  transform: translateX(16px);
}

/* Responsive: mobile layout */
@media (max-width: 768px) {
  .app-shell {
    flex-direction: column;
  }

  .account-bar {
    flex-direction: row;
    width: 100%;
    height: auto;
    padding: 0.375rem 0.5rem;
    overflow-x: auto;
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
  }

  .sidebar {
    width: 100%;
    height: auto;
    max-height: 50vh;
    overflow-y: auto;
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
  }

  .app-main {
    flex-direction: column;
  }

  .content {
    min-height: 0;
    flex: 1;
    overflow-y: auto;
  }

  .shortcuts-grid {
    grid-template-columns: 1fr;
  }

  .compose-editor .tiptap-content {
    min-height: 200px;
  }
}

/* Responsive: tablet */
@media (max-width: 1024px) and (min-width: 769px) {
  :root {
    --sidebar-width: 200px;
  }

  .nav-label {
    font-size: var(--text-xs);
  }
}

/* Print styles */
@media print {
  .account-bar,
  .sidebar,
  .compose-actions,
  .message-actions,
  .nav-compose-btn {
    display: none !important;
  }

  .content {
    margin: 0;
    padding: 1rem;
  }
}

/* Empty states */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem 1rem;
  color: var(--text-tertiary);
  text-align: center;
}

.empty-state p {
  font-size: var(--text-base);
  margin-bottom: 1rem;
}

/* Page header */
.page-header {
  margin-bottom: 1.5rem;
}

.page-subtitle {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  margin-top: 0.25rem;
}

/* Button sizes */
.btn-sm {
  padding: 0.25rem 0.625rem;
  font-size: var(--text-xs);
}